technical memorandum: interstate 10 and interstate 17 â€œspine

TECHNICAL MEMORANDUM:INTERSTATE 10 AND INTERSTATE 17“SPINE” CORRIDOR SUMMARY

CPHX

Note: This document presents a planning level assessment of the feasibility of various improvementstrategies for consideration when developing MAG’s NextGen RTP. The RTP process would include further technical evaluation and vetting of the strategies with stakeholders and the public.

Central Phoenix Transportation Framework Study

Technical Memorandum: Interstate 10 and Interstate 17 “Spine” Corridor Summary Page i of ii

August, 2013

Table of Contents

1.0 INTRODUCTION .................................................................................................................................................................. 1

1.1 BACKGROUND ............................................................................................................................................................................ 1

1.2 PURPOSE OF THIS REPORT ............................................................................................................................................................. 2

2.0 BACKGROUND.................................................................................................................................................................... 3

2.1 INTERSTATE 10 CORRIDOR IMPROVEMENT STUDY AND DRAFT ENVIRONMENTAL IMPACT STATEMENT/SECTION 4(F) EVALUATION ................... 3

2.2 INTERSTATE 17/BLACK CANYON FREEWAY CORRIDOR STUDY AND DRAFT ENVIRONMENTAL IMPACT STATEMENT/SECTION 4(F) EVALUATION .... 4

2.3 MAG MANAGED LANES NETWORK DEVELOPMENT STRATEGY (PHASE I) ............................................................................................... 4

2.4 SOUTHEAST CORRIDOR MAJOR INVESTMENT STUDY .......................................................................................................................... 9

3.0 OVERVIEW OF CORRIDOR STUDIES PROPOSALS ................................................................................................................ 13

4.0 THOUGHTS REGARDING ALTERNATIVE IMPROVEMENTS TO THE SPINE CORRIDOR .......................................................... 14

1.1 RUNWAY AIRSPACE ................................................................................................................................................................... 15

4.1 COST-CONSTRAINED CONCEPT .................................................................................................................................................... 19

4.2 EXPRESS LANES CONCEPT ........................................................................................................................................................... 20

5.0 WORKSHOP....................................................................................................................................................................... 23

1.1 WORKSHOP PURPOSE AND OBJECTIVES ......................................................................................................................................... 23

5.1 EXAMPLE PROJECTS ................................................................................................................................................................... 23

5.1.1. Interstate64/US-40, St. Louis, Missouri ....................................................................................................................... 23

5.1.2. Interstate 495 Capital Beltway, Washington, DC ........................................................................................................ 24

5.1.3. Interstate 15 Corridor, Salt Lake City, Utah ................................................................................................................. 24

5.1.4. Interstate 5/Columbia River Crossing, Portland, Oregon ............................................................................................ 25

5.2 WORKSHOP DISCUSSION ITEMS ................................................................................................................................................... 25

5.2.1. Consensus .................................................................................................................................................................... 25

5.2.2. Objectives .................................................................................................................................................................... 25

5.3 ALTERNATIVE IDEAS/CONCEPTS DEVELOPMENT .............................................................................................................................. 26

5.3.1. Spend the Available Money ......................................................................................................................................... 26

5.3.2. Should the Long-Term Vision have a “Cap” on the Roadway Footprint? .................................................................... 26

5.3.3. Airport Access .............................................................................................................................................................. 26

5.3.4. Near-Term Improvements ........................................................................................................................................... 26

5.4 SUMMARY OF ALTERNATIVES REVIEW ........................................................................................................................................... 26

6.0 RECOMMENDATIONS FOR PATH FORWARD ..................................................................................................................... 29

1.1 PATH FORWARD: INSTITUTIONAL ARRANGEMENTS FOR SPINE OVERSIGHT .......................................................................................... 29

6.1.1. “Cap the Footprint” ..................................................................................................................................................... 29

6.1.2. Potential Near-term Improvements ............................................................................................................................ 29

6.2 NEXT STEPS .............................................................................................................................................................................. 29

6.2.1. Footprint Definition ..................................................................................................................................................... 29

6.2.2. Project Evaluations ...................................................................................................................................................... 29

6.2.3. Environmental Studies ................................................................................................................................................. 29

6.2.4. Programming .............................................................................................................................................................. 29

Appendices

Appendix A Workshop Handouts

Appendix B Workshop Sign-in-Sheets

Appendix C Workshop PowerPoint Presentations

Appendix D Workshop Roll Plots and Other Exhibits

Appendix E Workshop Notes

Appendix F High-Level Cost Estimates for Conceptual Ideas

Appendix G Workshop Flip Chart Notes - Images


Page ii of ii Technical Memorandum: Interstate 10 and Interstate 17 “Spine” Corridor Summary

August, 2013

List of Figures

Figure 1-1 The “Spine” Corridor .............................................................................................................................................................. 1 Figure 2-1 Capacity Screening: 2031 MAG Regional Freeway Network ................................................................................................. 6 Figure 2-2 Constructabilty Screening: 2031 MAG Regional Freeway Network ..................................................................................... 6 Figure 2-3 Single-Lane High-Occupancy Toll System – Scenario 1.......................................................................................................... 7 Figure 2-4 Dual-Lane High-Occupancy Toll System – Scenario 2 ............................................................................................................ 7 Figure 2-5 Top Performing Segments Single-Lane High-Occupancy Toll System: 2031 ........................................................................ 8 Figure 2-6 Top Performing Segments Dual-Lane High-Occupancy Toll System: 2031 ........................................................................... 8 Figure 2-7 Southeast Corridor Major Investment Study Planning Area ................................................................................................. 9 Figure 2-8 Recommended Bundle of Transportation Improvements................................................................................................... 11 Figure 4-1 Evaluation of Runway Protection Zone: Existing Freeway Configuration .......................................................................... 16 Figure 4-2 Suggested Resolution of Runway Protection Zone Conflicts ............................................................................................... 17 Figure 4-3 Suggested Solution for Traffic Circulation with Redesigned Interchange ........................................................................... 18 Figure 4-4 Cost-Constrained Concept: Candidate Locations for DDIs and DHOVs ............................................................................... 19 Figure 4-5 Express lanes Concept: Candidate Locations for DDIs and DHOVs ..................................................................................... 22

List of Tables

Table 2-1 Travel Demand Projections ................................................................................................................................................... 10 Table 2-2 Recommendations from the Southeast Corridor Major Investment Study.......................................................................... 11 Table 3-1 Interstate 10 and Interstate 17 Corridor Studies Proposal ................................................................................................... 13 Table 4-1 Alternative 1: Cost-Constrained Concept ............................................................................................................................ 19 Table 4-2 Alternative 1 – Cost-Constrained Concept High-Level Probable Construction Costs ........................................................... 21 Table 4-3 Alternative 2 – Express Lanes Concept ................................................................................................................................. 21 Table 4-4 Alternative 2 – Express Lanes Concept High-Level Probable Construction Costs ................................................................. 22


Technical Memorandum: Interstate 10 and Interstate 17 “Spine” Corridor Summary Page 1 of 29

August, 2013

Technical Memorandum

Interstate 10 and Interstate 17 “Spine”

Corridor Summary

1.0 Introduction This Technical Memorandum provides information supporting the need to reexamine planning-level findings associated with

the release of draft environmental reviews conducted by the Federal Highway Administration (FHWA) and the Arizona

Department of Transportation (ADOT) in support of capacity enhancements along Interstate 10 (Maricopa Freeway) and

Interstate 17 (Black Canyon Freeway). These two facilities form a north-south, transportation corridor, which constitutes

“The Spine” of the region over which much of the travel in the Valley occurs (Figure 1-1). Information presented herein was

derived during conduct of an all-day workshop sponsored by the Maricopa Association of Governments (MAG) to examine

the attributes and characteristics of three alternative improvement schemes.

1.1 Background In 2001, the FHWA and the ADOT began developing a Draft Environmental Impact Statement (DEIS) and Section 4(f)

Evaluation in support of expanding Interstate 10 between the SR-51 (Piestewa Freeway)/SR-202L (Red Mountain Freeway),

the “Mini-Stack” system interchange, and SR-202L (Santan/South Mountain Freeways), the “Pecos Stack” system

interchange. The objective of this the DEIS/Section 4(f) process was to gain environmental clearance for the following

reconstruction actions:

Interstate 10/SR-143/48th Street traffic interchange;

Connections to the US-60 (Superstition Freeway) and Interstate 17 (Black Canyon Freeway) system interchanges;

Construction of an additional high occupancy vehicle (HOV) lane between Interstate 17 (Black Canyon Freeway)

and US-60 (Superstition Freeway); and

Implementation of a local-express lane concept, expanding the freeway to as many as 25 lanes for providing

additional capacity along Interstate 10.

In 2009, FHWA and ADOT began developing an DEIS/ Section 4(f) Evaluation in support of expanding Interstate 17

between the Interstate 10 at “The Split” system interchange near Phoenix-Sky Harbor International Airport and the SR-101L

(Agua Fria-Pima Freeway) at the “North Stack” system interchange. The objective of this DEIS/Section 4(f) Evaluation was

to gain environmental clearance for providing additional capacity through reconstruction of one of the oldest freeway

segments in Arizona, enhancements to existing traffic interchanges, and operational improvements to the Black Canyon

Freeway frontage roads.

Both environmental review actions are at significant decision points for the Region relative to continuing development of the

MAG Regional Freeway and Highway Program and the Regional Transportation Plan. As FHWA and ADOT have

completed the drafts of these two studies, MAG realized improvements proposed for both Interstate 10 and 17, which

combined form the critical north-south Spine Corridor, would significantly exceed program budgets identified for both

facilities. Presently, the program includes an allocation of approximately $1.3 billion for improving both freeways, which is

about one-third the total value of improvements under study in both DEIS/Section 4(f) studies. In addition, the

DEIS/Section 4(f) Evaluation resulted in the determination that significant improvements may be needed in the vicinity of

FIGURE 1-1

THE “SPINE” CORRIDOR

PECOS

STACK

SPLIT BROADWAY

CURVE

MINI- STACK

DURANGO

CURVE

STACK

NORTH

STACK

143ARIZONA


Page 2 of 29 Technical Memorandum: Interstate 10 and Interstate 17 “Spine” Corridor Summary

August, 2013

the “The Split” system interchange to accommodate new airspace regulations required by the Federal Aviation

Administration (FAA) for runways at Phoenix Sky Harbor International Airport. Certain mitigating actions are proposed in

the environmental documentation; however, resolution of this critical issue was determined to require further consultations

with FAA officials.

1.2 Purpose of this Report Given the significance of the decision point for MAG, FHWA and ADOT recommended reevaluating the environmental

studies process for both corridors and determining an appropriate direction for expanding capacity along both Interstate 10

and Interstate 17. As the regional transportation planning agency, MAG has had under study two significant projects that

will contribute to the decisions needed in this reevaluation: Southeast Corridor Major Investment Study, and MAG Managed

Lanes Network Development Strategy - Phase I. Preliminary findings have identified alternate cross-sections and priced-

congestion programs that could improve and enhance the capacity of both corridors. MAG is providing this data from these

studies to FHWA and ADOT and is proposing a workshop with the project’s key stakeholders to identify the appropriate

solution for adding capacity to the Interstates 10 and Interstate 17 Spine.

To facilitate reevaluation of information and findings presented in the DEIS/Section 4(f) Evaluation documentation, FHWA

and ADOT suspended the DEIS/Section 4(f) studies for both Interstate 10 and Interstate 17 in anticipation of additional

information from the MAG studies and the need for a more appropriate solution. Data developed and efforts completed

thus far will be incorporated into future environmental review actions needed to define and implement a solution for both

freeways. Also, as this reevaluation is under consideration, MAG, ADOT, and FHWA will be identifying interim “spot”

improvements along both Interstates 10 and 17 to ease existing congestion and improve travel through known bottlenecks.



August, 2013

2.0 Background The workshop began with presentations about existing transportation planning and environmental studies that were either in

process or recently completed in the vicinity of the Interstate 10 and Interstate 17 corridor. The following sections provide

summaries of those study efforts as well as information discussed by workshop participants about the anticipated outcomes

and/or recommendations.

2.1 Interstate 10 Corridor Improvement Study and Draft Environmental Impact Statement/Section 4(f) Evaluation

This I-10 Corridor Improvement Study, State Route 51 to Santan Freeway, was initiated in 2001. It examined the potential

for providing mainline widening and a local-express lane system for Interstate 10 between its junction with SR-51 (Piestewa

Freeway) and SR-202L (Red Mountain Freeway) northeast of downtown Phoenix – “Mini-Stack” – and the SR-202L

(Santan/South Mountain Freeway) – “Pecos Stack.” The distance of between these two system interchanges is

approximately 13 miles. The key feature of this conceptual plan to expand the capacity of Interstate 10 is development of a

collector-distributor (C-D) roadway and ramps between 40th Street and Baseline Road. This roadway is expected to reduce

significant traffic weaving movements that presently occur, due to separate, but fairly close, system interchanges with SR-143

(Hohokam Expressway) and US-60 (Superstition Freeway). This segment of Interstate 10, generally referred to as the

“Broadway Curve,” has been the subject of

past studies by ADOT to identify a solution

to the weaving movements. The studies

culminated in 1988 with the

recommendation to expand the C-D system

into a local-express lane system and extend

the area of improvement to the Interstate

10 junction with Interstate 17 – “The Split”

system interchange. This local-express lane

system was the primary focus of the

DEIS/Section 4(f) environmental studies

process that supported the I-10 Corridor

Improvement Study.

The local-express lane system consists of

general purpose lanes flanked by special

lanes designed to facilitate access to various

intersecting roadways. The general purpose

lanes in the center, not being encumbered

by exiting and entering traffic offer

“express” through movement. The special

lanes flanking the express lanes allow traffic

to exit and enter with less interference and

reduced weaving to access ramps. In

addition, the proposed local-express system

includes HOV lanes at the very center of the freeway. This concept, while clearly adding substantial capacity to Interstate 10,

requires a footprint that would be as wide as 25-lanes between SR-143 and US-60 – the “Broadway Curve.” As plans for this

segment of freeway were coming to light, stakeholders in the corridor questioned the overall wisdom of constructing the

freeway as proposed. Specifically, the City of Tempe, which is where the widest segments of the improved corridor would be

constructed, was concerned about potential environmental impacts upon adjacent businesses and residences. The City asked

MAG to look at whether other regional and multi-modal alternatives could be considered for the Broadway Curve and

Interstate 10 in general. Based on this request, MAG undertook and completed the Southeast Corridor Major Investment Study

(MIS) to address concerns raised by the ADOT proposal and evaluate potential alternative solutions to the need for

additional capacity on Interstate 10. Information relating to this study is summarized in a subsequent section of this

memorandum.

In the environmental review process for Interstate 10 between the “Pecos Stack” and “Mini-Stack,” ADOT identified

impacts to both the built and natural environments. As reported in the DEIS, most impacts could be mitigated and the

expanded freeway cross-section could successfully be integrated into the surrounding urban system that bordered the

Maricopa Freeway. Nevertheless, a significant potential issue was raised in March, 2010, by the FAA, which reviewed the

DEIS. The FAA found that the Build Alternative include a design for the “The Split” system interchange that violates

recently adopted airspace regulations relating to clearances required for runways at Phoenix Sky Harbor International Airport.

The DEIS identifies mitigation measures to satisfy FAA concerns. One would involve construction of a retaining wall to

minimize encroachment in to airport property. Another measure would involve construction of tunnels to accommodate

certain ramps associated with the proposed redesign of “The Split” system interchange to mitigate the airspace conflicts. All

measures added considerable cost to the proposed Build Alternative under study in the DEIS preparation process. The

DEIS notes that discussions with the FAA, ADOT, and the City of Phoenix, owner/operator of the airport, would continue

as the project move forward in an effort to find an acceptable resolution to the issue.

Regardless of the airspace conflict associated with redesign of “The Split” system interchange, which, ultimately, must be

resolved for the project to be implemented, the current MAG Regional Transportation Plan (RTP) only provides funding for

a portion of the improvements being studied within the context of the Interstate 10 Corridor Improvement Study and

assessed in the DEIS/Section 4(f) Evaluation. Specifically, $648.5 million is programmed in the current RTP, beginning in

Fiscal Year (FY) 2019, to widen Interstate 10 between 32nd Street and SR-202L (Santan/South Mountain Freeway) – the

“Pecos Stack.” The estimated cost of improvements under study in the DEIS is approximately $1.5 billion. This cost does

not account for actions to mitigate identified airspace conflicts associated with modifications at “The Split” system

interchange. Even assuming improvements at “The Split” system interchange can be put off to a future time, MAG still has

concerns about constructing the proposed 25-lane freeway east and south of 32nd Street through the Broadway Curve, when

there is no identified funding for improving the corridor to the north and west of 32nd Street to “The Split” system

interchange. There is a very real concern that widening Interstate 10 east of 32nd Street potentially will result in a traffic

bottleneck at the Salt River overcrossing, as inbound traffic entering Central Phoenix merges back down to the existing six

lanes.

Given these developments, MAG and ADOT, with concurrence from FHWA, suspended in July 2012 the

DEIS/Section 4(F) Evaluation process relating to proposed Interstate 10 improvements. There were two primary reasons

cited in support of suspension. First, the ability to construct the entire local-express land system, as envisioned in the

Interstate 10 Corridor Improvement Study and evaluated in the DEIS, is under considerable scrutiny, given that MAG has

had to balance out more than $7 billion worth of Regional Freeway and Highway Program improvements during the past

three years. Second, information from the Southeast Corridor Major Investment Study (MIS) conducted by MAG suggests a

narrower footprint, incorporating additional direct HOV (DHOV) traffic interchanges, and the potential for congestion

pricing could lead to better traffic flow along Interstate 10. These findings merit additional study.



August, 2013

2.2 Interstate 17/Black Canyon Freeway Corridor Study and Draft Environmental Impact State-ment/Section 4(f) Evaluation

This study began in 2009 and examined the potential for widening Interstate 17 from its junction with Interstate 10 at “The

Split” system interchange, southwest of Phoenix-Sky Harbor International Airport, to the “North Stack” system interchange

at SR-101L (Agua Fria/Pima Freeway), a distance of approximately 20 miles. The portion of Interstate 17 under study is

located entirely within the City of Phoenix.

Segments of Interstate 17 represent the

oldest portions of Arizona’s freeway

system. The earliest southern sections

opened in 1957 as Arizona State Route 69

(prior to receiving Interstate designation),

and the final northern sections were

completed in 1964. Since opening, the

Interstate 17 (Black Canyon Freeway) has

been widened to provide an additional

general purpose lane in each direction, and

HOV lanes were added in both directions

between McDowell Road and SR-101L

(Agua Fria/Pima Freeway) – “North

Stack.” Recent traffic counts by ADOT

indicate traffic volumes along this segment

of Interstate 17 range between 90,000 and

194,000 vehicles per day. Sections with

the highest traffic volumes are located

directly south of the system interchange at

SR-101L (Agua Fria/Pima Freeway).

The MAG RTP includes widening of this

segment of the Interstate 17 corridor

throughout its entire 20-mile length.

Although the actual lane count identified

in the RTP varies, the following

improvements are identified:

Add one HOV lane and one general purpose lane in each direction between the Interstate 10/Interstate 17 system

interchange southeast of downtown Phoenix – “The Split” – and the Interstate 10/Interstate 17 system interchange

northwest of downtown Phoenix – “The Stack;”

Rehabilitation of the facility to replace structures and pavement nearing the end of recommended/useful service life;

Add general purpose lanes in each direction between the “The Stack” and the Arizona Canal (number of lanes to be

identified through the DEIS/Section 4(f) Evaluation process);

Add one general purpose lane in each direction between the Arizona Canal and the “North Stack;” and

Rehabilitation of the facility to replace structures and pavement nearing the end of recommended/useful service life.

When the RTP was adopted November, 2003, the MAG Regional Council identified a program amount of $1.13 billion to

accomplish the improvements described above. This program amount was maintained through the 2009 rebalancing effort,

when $6.6 billion of the RFHP was moved to later years due to design cost over-runs and revenue shortages. However, this

segment of Interstate 17 did loose approximately $300 million in programmed improvements, when the Regional Council

adopted a rebalanced RFHP in 2012 developed in response to continuing revenue shortages. Therefore, the current amount

now in the RFHP for Interstate 17 (Black Canyon Freeway) improvements is $821.6 million.

Alternatives being generated for the Interstate 17/Black Canyon Freeway Corridor Improvement Study and being review

through the Federal DEIS/Section 4(f) Evaluation process were approaching an implementation amount in excess of

$2.5 billion; an amount well in excess of the RFHP amount for the adopted as part of the MAG RTP. The primary reason

for the high cost of alternatives costs is the right-of-way (ROW) acquisition associated with extensive widening of Interstate

17 north of the “The Stack.” The proposed widening project would occur along some of the densest commercial

development in the City of Phoenix. In addition to the extreme acquisition impacts associated with the proposed widening

and a cost far in excess of regional resources, it was recognized by ADOT, FHWA, and MAG that potential airspace

conflicts at the “The Split” system interchange, as noted by the Federal Aviation Administration, would significantly affect

any improvements to the Black Canyon Freeway. Therefore, the FHWA and ADOT suspended further work on the

DEIS/Section 4(f) Evaluation to permit additional assessment of alternative capacity enhancement proposals.

2.3 MAG Managed Lanes Network Development Strategy (Phase I) Arizona House Bill (HB) 2396, passed by the Arizona Legislature and signed by Governor Brewer on July 13, 2009, enables

the state, through ADOT, to consider the use of Public-Private-Partnerships (P3) as a tool for financing transportation

infrastructure in Arizona. This new law grants ADOT broad authority to partner with the private sector to build or improve

Arizona transportation facilities. Since the program’s inception, ADOT has established an Office of P3 Initiatives to

establish program guidelines and create a process for implementing the program.

Often when a P3 project is established, the public sector partners with the private sector to develop the transportation

project. Typically, funding for the project comes from both sectors. In an exchange for managing the risk of developing the

transportation project, the public sector grants a concession agreement to the private sector for a set period to allow recovery

of their funding with interest. During this set period, which can range from 30- to 100-years, the private sector is responsible

for operation and maintenance of the infrastructure. While the private sector funding recovery can be accomplished through

a variety of methods, the most common is the imposition of tolls on the transportation project during the set period.

Throughout the set period, and at the conclusion of the concession agreement, the public sector maintains ownership of the

transportation project.

In the Phoenix metropolitan area, ADOT has been coordinating with MAG to identify the potential for using P3 as a tool

for funding transportation improvements, especially in light of recent shortfalls that have been realized by declining

Proposition 400 revenues.1 Starting in June 2010 and continuing into September 2010, the Transportation Policy Committee

received presentations from MAG staff, ADOT staff, and P3 experts, including former USDOT Transportation Secretary

Mary Peters, about the potential for employing this financing method for the construction of managed lanes in the region.

The Transportation Policy Committee considered the topic and identified three policy issues related to P3 projects:

1 On November 2, 2004, the voters of Maricopa County passed Proposition 400 (formally known as the Maricopa County Transportation Excise Tax), which authorized the

continuation of an existing half-cent sales tax to support transportation system improvements in the MAG region. Proposition 400 provides a 20-year extension of the half-cent sales tax through calendar year 2025 to implement projects and programs identified in the MAG RTP. As a result of the global and national economic downturn, revenues have fallen short of projections requiring downward adjustments in project funding.



August, 2013

Does the MAG Region want to explore the use of P3, and tolls specifically, in the context of the overall

transportation system?

What is the potential pool of projects that might be considered? Should projects include those from Proposition

400?

How should the region use potential net revenues from P3 projects?

As these policy issues were identified, it was noted that P3 projects could cover a variety of transportation infrastructure,

including operations and maintenance of the existing system, expansion and improvements for transit, and adding new

highway capacity. During the course of Transportation Policy Committee discussions, a presentation was made to consider

Managed Lanes that would provide new capacity along the MAG Regional Freeway Network as an introduction to P3

opportunities for the Region. Managed Lanes could be implemented to supplement corridor capacity and would not require

all users to pay a toll to travel along freeway

corridors.

Often referred to as High-Occupancy Toll

(HOT) Lanes, these lanes are either

converted HOV lanes, or new lanes

constructed along existing freeway corridors.

The lanes are signed free for carpoolers and

busses and also are offered for use to toll-

paying single-occupant vehicles (SOVs). In

most locations, tolls are varied electronically

based upon demand for the managed lanes.

If the free general-purpose lanes are

congested, then tolls are raised. Increasing

the toll decreases the number of “choice”

drivers and keeps travel within the managed

lanes as free-flow as possible. This

management of the lanes keeps the trip time

reliable for the carpoolers, busses, and the

toll-paying SOV commuter. The general

purpose lanes remain toll-free to all commuters not willing to pay for an uncongested travel time.

Managed Lanes are in various stages of development in 19 urban areas of the United States. Of these locations, eight urban

areas presently have Managed Lanes open to traffic and in operation; another three locations are under construction. The

most ambitious project being developed as a P3 operation by the Virginia Department of Transportation (VDOT) and

TransUrban Corporation is along the southwest leg of Interstate 495 – the Capital Beltway, between Interstates 95 and 395

and the Potomac River. The key promise of this $2 billion project is not only to provide 56 new lane-miles of capacity, but

to replace over 50 aging and deficient overcrossing structures of the freeway that would have taken the VDOT decades to

complete through conventional methods.

While it is possible to develop Managed Lane facilities along individual corridors, it might be difficult to assess the ability of

an individual corridor to function within the context of the entire MAG Regional Freeway System. Given this opportunity, a

multi-phase MAG Managed Lanes Network Development Strategy has been initiated to establish the feasibility for

introducing this concept to the Phoenix metropolitan area. A request was presented to the MAG Transportation Policy

Committee to conduct the first phase of this proposed Development Strategy by conducting a System-Wide Managed Lanes

Feasibility Study. The following tasks have been defined for Phase 1:

Assessment of Existing and Future HOV Lane use;

Identification of critical gaps in the system;

Assessment of basic soundness of a Managed Lanes Network in the MAG Region;

Formulation of a MAG Managed Lanes policy; and

Selection of corridors for a pilot Managed Lane project.

Pending acceptance of the findings from this first phase, the MAG Managed Lanes Network Development Strategy could

continue into additional phases. A second phase is envisioned to analyze the pilot Managed Lanes corridors identified in the

initial effort. A third and final phase would analyze other promising freeway corridors to assess feasibility for implementing

the Managed Lanes concept. In both of these latter two phases, work programs would encompass preparing demand

projections, preparing revenue projections, assessing investment options, and drafting a corridor implementation strategy.

As the System-Wide Managed Lanes Feasibility Study is under development, an outreach program also would be conducted

to identify the public’s attitudes towards the possible introduction of tolling to the MAG Region. This project would be

separate from the feasibility study and conducted by a consultant versed in public opinion gathering and analysis. The goal of

this outreach effort would be to provide information to the Transportation Policy Committee related to the three policy

issues associated with a potential P3 program in the MAG Region, as cited earlier.

On November 15, 2010, the MAG Regional Council authorized procurement of consultant services to implement Phase 1 of

the MAG Managed Lanes Network Development Strategy. Phase 1 will provide information needed for consideration by

MAG of P3 opportunities as part of an overall Managed Lanes strategy in the Phoenix metropolitan area, which could

facilitate the operation of existing HOV lanes as HOT lanes. The Phase 1study consultant has developed seven planning

papers addressing the following topics:

Project Goals and Objectives;

Legal and Regulatory Issues;

HOV Hours of Operation;

HOV Occupancy;

HOV Separation Treatment;

Pricing and Tolling Methods; and

Active Traffic Management and Managed Freeways.

A summary of suggestions presented in these papers is attached to this memorandum, and links to the papers themselves can

be found on the MAG Website at: http://www.azmag.gov/Projects/Project.asp?CMSID=4190.

Recent, related efforts include a Tier 1 screening of the MAG Regional Freeway system to identify segments that could be

suitable for development of the Managed Lanes operating concept. The Tier 1 screening considered existing and projected

HOV demand, available capacity, and constructability as parameters for the assessment. The overall result of this screening

reveals that the most favorable attributes for capacity and operations tend to contribute to the least favorable characteristics

for constructability. For example, the Tier 1 screening of SR-51 (Piestewa Freeway) suggests that existing and future travel

demand would be very favorable for toll pricing under a Managed Lanes concept. However, Managed Lanes would be

difficult to construct to full design standards between the freeway’s interchange with Interstate 10 and SR-202L (Red

Mountain Freeway) – “Mini-Stack” – and Northern Avenue (see Figures 2-1 and 2-2). Figures 2-3 through 2-6 show the

most promising freeway corridors for implementing single- and dual-lane Managed Lanes – or HOT lanes – systems.

Figure 2-6 specifically shows the entire length of the Spine Corridor is forecast to consist of top performing segments in

2031.

http://www.azmag.gov/Projects/Project.asp?CMSID=4190.



August, 2013

Source: Managed Lanes Concept Tier 1 Screening of the MAG Regional Freeway System, MAG Managed Lanes Network Development

Strategy.

FIGURE 2-2

CONSTRUCTABILTY SCREENING: 2031 MAG REGIONAL FREEWAY NETWORK

FIGURE 2-1

CAPACITY SCREENING: 2031 MAG REGIONAL FREEWAY NETWORK


Strategy.



August, 2013


Strategy.

FIGURE 2-4

DUAL-LANE HIGH-OCCUPANCY TOLL SYSTEM – SCENARIO 2


Strategy.

FIGURE 2-3

SINGLE-LANE HIGH-OCCUPANCY TOLL SYSTEM – SCENARIO 1



August, 2013

FIGURE 2-6

TOP PERFORMING SEGMENTS DUAL-LANE HIGH-OCCUPANCY TOLL SYSTEM: 2031


Strategy. Source: Managed Lanes Concept Tier 1 Screening of the MAG Regional Freeway System, MAG Managed Lanes Network Development

Strategy.

FIGURE 2-5

TOP PERFORMING SEGMENTS SINGLE-LANE HIGH-OCCUPANCY TOLL SYSTEM: 2031



August, 2013

2.4 Southeast Corridor Major Investment Study During the course of the Interstate 10 Corridor Improvement Study and supporting DEIS/Section 4(f) Evaluation, MAG

member agencies raised questions about the investment being made in this corridor. There were deemed to be needed

alternate transportation options, in addition to ADOT’s proposal to widen Interstate 10 and improve system and traffic

interchanges to accommodate growing travel demand between the East Valley and Central Phoenix. The Southeast Corridor

MIS has been one response by MAG to the concerns raised. The area of study and corridors that received focused attention

are shown in Figure 2-7. The Southeast Corridor MIS planning area is bounded by Interstate 10 (Papago Freeway) and SR-

202L (Red Mountain Freeway) on the north, SR-101L (Price Freeway) on the east, the Gila River Indian Community border

on the south, and Interstate 17 (Black Canyon Freeway) and the 23rd Avenue alignment on the west. The study area includes

the Town of Guadalupe and parts of Phoenix, Tempe, and Chandler. The Southeast Corridor MIS work program included

the following tasks:

Review of all transportation investments proposed for the Southeast Corridor, including those proposed along other

parallel facilities, such as SR-101L (Price Freeway) and SR-202L (Red Mountain Freeway);

Study of demand in the travelshed between the East Valley and Central Phoenix to identify the potential for

alternative transportation mode strategies to accommodate demand in addition to freeway widening scenarios;

Consultation with project stakeholders on the project’s findings and recommendations; and

Development of a preferred investment strategy for the Southeast Corridor.

Subsequent to receiving notice to proceed in June, 2010, the study team developed, studied, and analyzed three bundles of

more than 25 different transportation mode alternatives to accommodate travel demand forecasts developed for the planning

area that reaches from Downtown Phoenix to Downtown Chandler. Information generated by this study benefited not only

the MIS effort, but has also significantly contributed valuable information to the DEISs prepared for Interstate 10 Corridor

Improvement Study and SR-202L (South Mountain Freeway).

The Southeast Corridor MIS identifies compatible transportation elements designed to improve overall mobility within a

planning area that includes a major portion of the Spine Corridor, which is the subject of this Technical Memorandum. The

transportation system recommendations of the Southeast Corridor MIS would provide connections between many of

Maricopa County’s major activity centers, as well as access to regional, national, and international destinations. At present,

freeways and roadways in the planning area experience recurring weekday congestion, and the area’s population is expected

to double between 2010 and 2030, placing increased demand on its transportation infrastructure.

The Southeast Corridor MIS identifies multimodal transportation investment options to the currently planned widening of

Interstate 10 between the Interstate 10/Interstate 17 system interchange – “The Stack” – and the Interstate 10 system

interchange with SR-202L (Santan Freeway) – the “Pecos Stack,” including the Broadway Curve. Transportation investment

options were explored to address projected increases in area employment and population and the resulting increase in

roadway congestion levels, as demonstrated by the following findings from previous studies:

The 2006 MAG Freeway Level of Service Study indicates every freeway within the Southeast Corridor MIS planning

area currently experiences recurring congestion; and

A major increase in the number of congested intersections operating at level of service (LOS) E and F will occur

between 2012 and 2030, despite construction of arterial improvements identified in the current RTP.

Transportation performance measures, including traffic congestion, travel speeds, and transit utilization, indicate the general

need for additional or alternative investment in transportation infrastructure and services. Key transportation performance

findings documented in the MAG Southeast Corridor MIS study include:

Previous studies indicate that every freeway within the study area experiences some recurring congestion;

The most significant freeway delays are found on Interstate 10 northbound between Chandler Boulevard and US-60

and on US-60 westbound between Mill Avenue and Priest Drive during the AM peak period. During the PM peak

period, the most significant bottlenecks in the planning area are on Interstate 10 eastbound between Interstate 17

and Guadalupe Road and on eastbound US-60 between Interstate 10 and Rural Road (Scottsdale Road);

FIGURE 2-7

SOUTHEAST CORRIDOR MAJOR INVESTMENT STUDY PLANNING AREA

Source: Southeast Corridor Major Investment Study, MAG, July, 2010.

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Slightly higher average speeds are experienced during peak hours on the HOV facilities than on the general purpose

freeway lanes;

Arterial congestion primarily is a peak-hour problem, where through traffic experiences significant delays at

numerous intersections during the morning peak hours, and even more intersections during the afternoon peak

hours;

Within the planning area, local fixed-route bus service carried more passengers than any other transit mode in Fiscal

Year (FY) 2009, followed by light rail transit (LRT), circulator bus, and express bus;

Local bus routes with the highest ridership in the planning area operate within or through the central Phoenix area;

however, south Phoenix and Tempe east-west crosstown routes (Broadway Road, Southern Avenue, and Baseline

Road) have strong existing ridership; and

The Interstate 10 East RAPID (Ahwatukee to downtown Phoenix Express) accounts for more than one third

(37 percent) of the express route ridership in the planning area, while the three Chandler Express routes (540, 541,

and 542) account for approximately 24 percent of the express bus ridership.

Travel demand projections provide a general indication of future travel patterns within and through the study area. Results

from the MAG 2030 travel demand model indicate the following trends (see Table 2-1):

The top general destinations for trips from the south Tempe, Chandler, and Northern Pinal County area include:

o Southeast and east valley areas (Mesa, Gilbert and Pinal County);

o North Tempe (north of Baseline Road); and

o Central Phoenix north area (including Sky Harbor International Airport, Uptown Phoenix, and

Camelback/Biltmore area).

TABLE 2-1 TRAVEL DEMAND PROJECTIONS

Completed June 2012

Sub-Area 2010 Percent of Trips 2030 Percent of Trips

Study Area Person Trips From Study Area

Southeast and East Valley Areas 43% 44%

North Tempe 25% 20%

Central Phoenix North Area 18% 17%

All Other Areas Combined 13% 19%

Total 100% 100%

Study Area Person Trips To Study Area

Southeast and East Valley Areas 69% 75%

North Tempe 13% 10%

All Other Areas Combined 18% 16%

Total 100% 100%

Source: Southeast Corridor Major Investment Study, Maricopa Association of Governments (MAG), July 2012.

The areas of the region that generate the most trips destined to the south Tempe, Chandler, and Northern Pinal

County area include:

o Southeast and east valley area (Mesa, Gilbert and Pinal County); and

o North Tempe (north of Baseline Road).

Trips from the central Phoenix north area, which is considered a leading destination, represents only six percent of

the total daily person trips; however, it should be noted that a significant number of trips, approximately two-thirds

in 2010 and three-quarters in 2030, are from the southeast and east valley areas.

Approximately one-fifth (20.4 percent in 2010 and 19.5 percent in 2030) of the peak period trips destined for the

downtown Tempe/ASU area are from the south Tempe, Chandler and Northern Pinal County area.

Other areas that have a high level of trips destined for the downtown Tempe/ASU area include:

o Southeast valley area (Mesa and Apache Junction); and

o Central Phoenix north area (including Sky Harbor Airport, Uptown Phoenix, and Camelback/Biltmore area).

Areas that have a high level of trips destined for the downtown Phoenix include:

o Nearly 40 percent of the trips destined for the downtown Phoenix area are from the Central Phoenix north area

in both 2010 and 2030.

o All east valley areas combined (excluding Scottsdale) comprise approximately 20 percent of the trips; and

o Trips from the south Tempe, Chandler and Northern Pinal County area comprise only approximately eight

percent of the trips to downtown Phoenix.

Key findings of the Southeast Corridor MIS serve as an outline of the primary elements required to develop a recommended

bundle of transportation investment options. The transportation improvement options included in the recommended bundle

offer a relatively high level of performance (average freeway travel speeds, average freeway volumes, and new system-wide

transit riders) and efficiency (benefit/cost and transit boarding per revenue mile) compared to the other transportation

improvement options considered. In addition, the improvements generally performed well with respect to the evaluation

criteria.

The recommended bundle of transportation options includes Managed Lanes on Interstate 10/Interstate 17 (including

DHOV ramps) and exclusive guideway transit service on Southern and Central Avenues between the Phoenix central

business district (CBD) and Rural Road (Table 2-2 and Figure 2-8). Other transportation improvement options included in

the recommended bundle include extension of the modern streetcar in Tempe along Rio Salado Parkway and Southern

Avenue, as well as potential exclusive guideway transit extensions to Chandler’s CBD via Rural Road or Arizona Avenue.

Excluding the optional exclusive guideway transit extension to the Chandler CBD, the total estimated capital and operating

cost (operating cost for transit only) for the recommended bundle is $2.96 billion. Approximately 75% of the total estimated

cost is for public transit investments ($2.23 billion) including 20‑year operating costs. The total estimated capital cost per

corridor mile constructed (Managed Lanes + transit) is approximately $68.6 million. The recommended transportation

investment options will provide enhanced access to local and regional activity centers, provide expanded multimodal

transportation options, and offer potential user benefits based on personal time and fuel savings



August, 2013

.

TABLE 2-2 RECOMMENDATIONS FROM THE SOUTHEAST CORRIDOR MAJOR INVESTMENT STUDY

Completed June 2012

Concept Description/Location

Length in

Study Area

(miles)

Managed Lanes Interstate 10 and Interstate 17 - Pecos Stack TI to Stack TI 20.0

New DHOV Ramps Interstate 17/Washington Street

Interstate 17/Central Avenue

Interstate 10/SR-143

Interstate 10/Carver Road

Interstate 10/Galveston Road

---

Exclusive Guideway Transit Southern Avenue/Central Avenue – Phoenix CBD to Rural Road 11.5

Exclusive Guideway Transit Rural Road – Southern Avenue to University Drive 2.0

Potential Exclusive Guideway Transit Arizona Avenue – Chandler CBD to Rural Road and Southern

Avenue via Arizona Avenue

2.01

Potential Exclusive Guideway Transit Rural Road – Chandler CBD to Rural Road and Southern

Avenue via Rural Road

8.01

Modern Streetcar Rio Salado Pkwy - Extension from Mill Avenue to SR-101L 3.5

Modern Streetcar Southern Avenue - Extension from Mill Avenue to Rural Road 1.0

1 Total miles of extension (within study area + outside of study area) = ~11.0 miles

Source: Southeast Corridor Major Investment Study, Maricopa Association of Governments (MAG), July 2012.

FIGURE 2-8

RECOMMENDED BUNDLE OF TRANSPORTATION IMPROVEMENTS

Source: Southeast Corridor Major Investment Study, MAG, July, 2010.

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3.0 Overview of Corridor Studies Proposals Table 3-1 summarizes the proposed improvements recommended by the Corridor Improvement Studies conducted for

Interstate 10 and Interstate 17 and evaluated in the supporting DEIS/Section 4(f) Evaluation process. Graphics displaying

these proposed improvements to The Spine Corridor are provided in the Appendix of this report. Generally, proposed

improvements to Interstate 17 would involve widening the freeway to include two new general purpose (GP) lanes with a

new HOV lane south of Van Buren Street. Improvements proposed for Interstate 10 also would involve substantially

widening the freeway with to include a varying combination of new GP, HOV, and collector/distributor (C/D) lanes.

TABLE 3-1 INTERSTATE 10 AND INTERSTATE 17 CORRIDOR STUDIES PROPOSAL

Location Eastbound/Southbound Westbound/Northbound

SR-101L North Stack to Thomas Rd

Thomas Rd to Van Buren St VARIES VARIES

Van Buren St to Interstate

10/Interstate 17 Split

Interstate 10/Interstate 17 Split to

40th

St

40th

St to SR-143

SR-143 to US-60

US-60 to Baseline Rd

Baseline Rd to SR-202L Pecos Stack

LEGEND: Existing GP Lane Existing HOV Lane New GP Lane New HOV Lane New C/D Lane

The two corridor improvement studies, the recommendations of which were subject to environmental review in the DEISs,

also propose several key spot improvement elements, such as:

New flyover Direct Connector ramps linking Interstate 10 with SR-143/Hohokam Expressway to accommodate

eastbound-to-northbound traffic and southbound-to-eastbound traffic.

New HOV ramps at ”The Split” system interchange connecting Interstate 10 HOV lanes to new Interstate 17 HOV

lanes.

New DHOV ramps on Interstate 17 at:

o Central Avenue

o Jefferson /Adams Streets

o Between the Arizona Canal and Peoria Avenue

o Between Greenway Road and Bell Road.

New Direct Connector HOV ramps linking SR-101L (Agua Fria Freeway) with Interstate 17 to accommodate

eastbound-to-southbound traffic and northbound-to-westbound traffic.

It is worth noting that construction of Direct Connector HOV ramps at the system interchange of Interstate 10 with

SR-202L (Santan Freeway) – the “Pecos Stack” – recently was completed.



August, 2013




August, 2013

4.0 Thoughts Regarding Alternative Improvements to The Spine Corridor As evident from information presented earlier, there are major constraints to consider along The Spine Corridor. These

include funding feasibility, runaway airspace compatibility, right-of-way availability, adjacent development, and sensitive

environmental receptors. The two corridor studies prepared for Interstate10 and Interstate 17 considered many of these

constraints in detail. However, as noted above, those studies did not address the constraint of funding feasibility nor directly

address the issue of airspace compatibility.

To facilitate future efforts related to development of a conceptual master plan for The Spine Corridor, MAG assigned their

consultant team, Wilson & Company, to develop two conceptual ideas for the corridor that provide some preliminary

consideration of each of these two significant constraints. Wilson & Company is currently consultant to MAG for delivering

the Central Phoenix Transportation Framework Study (CPHX), which has the purpose of identifying a long-range vision for

transportation facilities in the central portion of the MAG region. The CPHX study area, bounded by SR-101L on the west,

north, and east, and the existing and proposed SR-202L on the south, fully incorporates The Spine Corridor.

The initial focus of the supplementary planning effort by Wilson & Company was examination of design and configuration

changes at “The Split” system interchange to mitigate airspace infringement. Wilson & Company also generated a

cost-constrained concept for improving The Spine Corridor that recognizes constraints on available funding, based on the

MAG RTP. In addition, MAG requested its consultant to prepare a second concept focusing on a network of Managed

Lanes, as described earlier. Each concept includes modifications to Interstate 10 and Interstate 17 between the “North

Stack” and “Pecos Stack” and includes recommended modifications to “The Split” system interchange as well as

accommodation of the 24th Street traffic interchange, which provides access to the west end of the airport. Graphic

illustrations of each corridor improvement concept are provided in the Appendix.

1.1 Runway Airspace The south runway (Runway 7R/25L) of Phoenix Sky Harbor International Airport was constructed in 1998. Its construction

resulted in portions of “The Split” system interchange infringing on the navigable airspace required for safe landing and

take-off based on FAA regulations. As of today, portions of the northbound I-17 and eastbound I-10 lanes at “The Split”

system interchange are located within the Runway Protection Zone (RPZ) and Runway Obstacle Free Area (OFA). The

RPZ is a trapezoidal surface area off the end of the runway defined to enhance protection of people and property on the

ground. The OFA is an area at the end of the runway free of above ground objects except for objects needed for airport

functions. Freeway lane infringements were not noted at the time the south runway was constructed.

As the Interstate 10 Corridor Improvement Study and preparation of the DEIS/Section 4(f) documentation proceeded, FAA

Form 7460-1, Notice of Proposed Construction or Alternation, was submitted to the FAA for review. This form provides

information to the FAA regarding proposed structures that might affect airport operations. The FAA uses the information

to determine whether development actions would pose safety concerns for airport operations. The FAA review of the draft

Form 7460-1 submittal for the express/local lanes concept, as proposed under the Build Alternative, was approved in the

summer of 2004. A second Form 7460-1 was submitted by ADOT presenting evaluation of design options for

accommodating westbound I-10 local lanes within the requirements of FAA regulations; it was approved by the FAA in

August, 2009. Subsequent to the August approval, the FAA adopted new airspace regulations pertaining to “one engine

inoperable procedures,” which were accompanied by decisions regarding an enhanced enforcement policy. The

DEIS/Section 4(f) Evaluation prepared for I-10 Corridor Improvement Study includes assessments of two design options –

Retaining Wall and Covered Roadway – to address concerns raised by the FAA. MAG recognized in 2005 potential conflicts

of the proposed freeway design with existing regulations. MAG raised the issue again in 2009, indicating to ADOT that

alteration of “The Split” system interchange would require conformance to the FAA regulations. In March, 2010,

responding to the new airspace regulations, the FAA raised objections to the proposed improvements associated with the

Build Alternative, which resulted in development of the Retaining Wall and Covered Roadway design options.

As part of the development of transportation system improvement alternatives for the CPHX study area, one goal was to

provide a potential solution to the conflicts of the south runway Phoenix Sky Harbor International Airport relative to the

new airspace regulations. Solutions developed and presented in the Interstate 10 Corridor Improvement Study

DEIS/Section 4(f) Evaluation only noted potential conflicts with the Interstate 10/Interstate 17 system interchange and 24th

Street traffic interchange providing access to the airport. Further examination of this subject revealed specific conflicts of the

ramps and other components of the proposed redesign of “The Split” system interchange with respect to vertical and

horizontal requirements for the Runway Protection Zone (RPZ) and the Object Free Area (OFA) of the south runway.

These conflicts are illustrated in Figure 4-1. The Interstate 17 northbound lanes, which fly over the Interstate 10 westbound

lanes, are in conflict with the south runway RPZ. It is clear from Figure 4-1 that portions of Interstate 17, Interstate 10, and

24th Street also are located within the designated OFA, which extends 2,700 feet beyond the end of south runway along the

runway centerline. Redesign of this system interchange contemplated by the Interstate 10 Corridor Improvement Study

Build Alternative would increase the degree and magnitude of the airspace conflicts rather than mitigate them. Therefore,

additional study of the redesign and potential mitigation design options is appropriate.

Figure 4-2 illustrates a potential solution that was developed by Wilson & Company to address both vertical and horizontal

issues associated with the south runway. Violating elements of “The Split” system interchange would be shifted slightly

south and west out of the OFA. The current alignment of 24th Street, south of Sky Harbor Circle, which crosses through the

OFA, would be abandoned, and the 24th Street traffic interchange with Interstate 10 would be eliminated. Shifting the

alignment of “The Split” system interchange also would help with construction of the depressed lanes on Interstate 10. More

importantly, this concept for modifying the system interchange can be constructed within the same right-of-way

requirements identified for Build Alternative design options while removing the airspace conflicts.

The vertical profile of “The Split” system interchange would be lowered by depressing the Interstate 10 mainline (i.e.,

General Purpose lanes) and HOV/HOT lanes (Grade -1). In addition, 21st Street would be extended north of Interstate 17

to Sky Harbor Circle South at the same grade. The Interstate 17 mainline and new HOV/HOT Direct Connector ramps

would be constructed at-grade (Grade 0), and the southbound (east) Interstate 17 to westbound (north) Interstate 10 flyover

ramp would become the highest point of the system interchange just one level above grade (Grade +1). Still, there would be

a need to install special low-mast lighting (similar to that installed along SR-143 at the east end of the airport) on this highest

flyover ramp to assure compliance with the 62:1 slope requirement for the runway flight path.

As noted above, the existing portion of 24th Street between Interstate10 and Sky Harbor Circle South violates the OFA.

Elimination of this roadway potentially would have a negative impact on airport access. Therefore, the redesigned system

interchange would route westbound Interstate 10 and northbound 24th Street traffic bound for the airport in one of two

ways, as illustrated in Figure 4-3. A new off-ramp could be constructed around the corner, so to speak (shown as dashed line

in Figure 4-3), along the east side of Interstate 10. This ramp would be at the grade of the Interstate 10 mainline (Grade -1),

as described above. It would be outside the RPA and OFA. A second route would involve the new connection/extension of

21st Street from University Drive north to Sky Harbor Circle South and Buckeye Road on the west side of the system

interchange. University Drive would connect from 21st Street eastward to a new traffic interchange at Interstate 10 southwest

of the Old Tower, where traffic would have access to Interstate 10 and Old Tower Road.



August, 2013

Conflict with Object Free Area

FIGURE 4-1

EVALUATION OF RUNWAY PROTECTION ZONE: EXISTING FREEWAY CONFIGURATION



August, 2013

FIGURE 4-2

SUGGESTED RESOLUTION OF RUNWAY PROTECTION ZONE CONFLICTS



August, 2013

FIGURE 4-3

SUGGESTED SOLUTION FOR TRAFFIC CIRCULATION WITH REDESIGNED INTERCHANGE



August, 2013

FIGURE 4-4

COST-CONSTRAINED CONCEPT: CANDIDATE LOCATIONS FOR DDIS AND DHOVS

Cost-Constrained Concept Improvements

Candidate DDI Conversion Location

Candidate DHOV Locations

4.1 Cost-Constrained Concept Table 4-1 provides a summary of the geometry associated with the Cost-Constrained concept. As indicated earlier, this

concept does not include any new lanes on Interstate 17 north of “The Stack” system interchange. Between “The Stack” and

“The Split” system interchanges, one general purpose (GP) lane and two HOV lanes would be added. Improvements to

Interstate 10 vary, but generally consist of an additional GP lane.

TABLE 4-1 ALTERNATIVE 1: COST-CONSTRAINED CONCEPT


SR-101L North Stack to Interstate

10/I17 Stack

Interstate 10/Interstate 17 Stack to

Interstate 10/Interstate 17 Split

Interstate 10/Interstate 17 Split to

24th

St

24th

St to 32nd

St

32nd

St to SR-143

SR-143 to US-60

US-60 to SR-202L Pecos Stack

LEGEND: Existing GP Lane Existing HOV Lane New GP Lane New HOV Lane New C/D Lane

In addition to these mainline improvements, the Cost-Constrained concept also incorporates several spot improvements,

including:

New flyover ramps for SR-143 for eastbound-northbound traffic and southbound-eastbound traffic.

Modifications to the “The Split” system interchange and 24th Street traffic interchange to conform to airspace

requirements. These modifications require depressing Interstate 10 and eliminating existing 24th Street traffic

interchange. Collector/distributor lanes are not included in this concept, due to clearance issues associated with

south runway of Phoenix Sky Harbor International Airport.

Candidate locations along Interstate 10 for converting existing interchanges into Diverging Diamond Interchanges

(DDIs) (Figure 4-4):

o Chandler Boulevard

o Ray Road

o Warner Road

o Elliot Road

o 32nd Street.



August, 2013

Candidate DHOV locations include:

o Interstate 10 -

Galveston Street

Carver Road

o Interstate 17 -

Central Avenue

15th Avenue

Van Buren Street

Mountain View Road

Paradise Lane

Yorkshire Drive/Utopia Road.

Candidate Direct Connector HOV Ramps:

o Interstate 10 at SR-143/Hohokam Expressway (westbound to northbound and southbound to eastbound)

o “The Split” – Interstate 10 westbound to Interstate 17 northbound (west) and Interstate 17 southbound (east) to

Interstate 10 eastbound

o Interstate 17 at SR-101L (Agua Fria Freeway) – “North Stack” (eastbound to southbound and northbound to

westbound).

Candidate Two-Lane exit ramps (“Choice Lanes”) along Interstate 10 Westbound:2

o Ray Road

o Warner Road

o Elliot Road

o Broadway Road

o SR-143 and 40th Street.

Candidate Two-Lane (Choice Lane) exit ramps along Interstate 10 Eastbound:

o 32nd Street

o 40th Street

o Elliot Road

o Warner Road

o Ray Road

o Chandler Boulevard.

Candidate Two-Lane (Choice Lane) exit ramps along Interstate 17 Northbound:

o Indian School Road

2 “Choice Lanes” include an exit-only lane and an inside through-exit lane.

o Camelback Road

o Bethany Home Road

o Peoria Avenue

o Union Hills Drive.

Candidate Two-Lane (Choice Lane) exit ramps along Interstate 17 Southbound:

o Peoria Avenue

o Bethany Home Road

o Camelback Road

o Thomas Road.

Active Traffic Management Measures, such as variable speed limits and improved ramp metering.

Braiding the westbound Baseline Road on-ramp and US-60 exit ramp.

Table 4-2 represents high-level preliminary construction costs based on the improvements described above. The total

estimate cost of the three separate potential improvement segments is $1,263,646,000. The estimate does not include any

costs associated with possible right-of-way acquisition and/or relocations. Also, this estimate does not include a contingency

factor of 30 percent, generally added to ADOT project cost estimates. The ADOT contingency roughly equate to

$38 million. The costs shown in Table 4-2 are stated in 2012 dollars with no escalation for inflation.

4.2 Express Lanes Concept The Express Lanes concept idea focuses on increasing capacity through conversion of existing HOV lanes to HOT lanes,

providing additional HOT lanes, generally adding one GP lane, and constructing C/D lanes along a limited section of

Interstate 10. This concept allows for an opportunity to explore other funding options by introducing the potential for

generating revenue through congestion-pricing applied to the HOT lanes with respect to SOVs (Table 4-3.)

Similar to the Cost-Constrained concept, the Express Lanes concept also contains several spot improvements, including:

New flyover ramps to SR-143 for eastbound-northbound traffic and southbound-eastbound traffic.

Modifications to the “The Split” system interchange and 24th Street traffic interchange to conform to airspace

requirements. These modifications require depressing Interstate 10 and eliminating existing 24th Street traffic

interchange. Collector/distributor lanes are not included in this concept, due to clearance issues associated with

south runway of Phoenix Sky Harbor International Airport.

Candidate locations along Interstate 10 for converting existing interchanges into Diverging Diamond Interchanges

(DDIs) (Figure 4-5):

o Chandler Boulevard

o Ray Road

o Warner Road

o Elliot Road

o 32nd Street.



August, 2013

TABLE 4-2

ALTERNATIVE 1 – COST-CONSTRAINED CONCEPT HIGH-LEVEL PROBABLE CONSTRUCTION COSTS

Major Item Description

Potential Interstate 17/Interstate 10 Spine Segment

SR-101L to

McDowell McDowell to Baseline

Baseline to

SR-202L

Earthwork $ 3,821,000 $ 28,763,000 $ 7,771,000

Base and Surface Treatment $ 1,663,000 $ 60,299,000 $ 11,784,000

Drainage $ 6,000,000 $ 29,400,000 $ 10,660,000

Structures $ 74,531,000 $ 187,517,000 $ 13,937,000

Traffic $ 25,725,000 $ 58,125,000 $ 20,288,000

Roadside Development $ 3,051,000 $ 6,615,000 $ 2,399,000

Incidentals $ 121,055,000 $ 390,950,000 $ 70,487,000

Other Project Costs

Utility Relocations (1%) $ 2,358,000 $ 7,617,000 $ 1,373,000

Pavement Incentives (3.5% of Pvmt) $ 58,000 $ 2,110,000 $ 412,000

Design Engineering (10%) $ 23,826,000 $ 77,140,000 $ 13,911,000

TOTAL $ 262,088,000 $ 848,536,000 $ 153,022,000

NOTE: A contingency factor of 30 percent, generally added to ADOT total project cost estimates has not been included. The ADOT

contingency roughly equates to $38 million.

TABLE 4-3 ALTERNATIVE 2 – EXPRESS LANES CONCEPT


SR-101L North Stack to Thomas Rd

Thomas Rd to Van Buren St VARIES VARIES

Van Buren St to Interstate 10/Interstate 17

Split

Interstate 10/Interstate 17 Split to 32nd

St

32nd

St to SR-143

SR-143 to US-60

US-60 to Baseline Rd

Baseline Rd to Warner Rd

Warner Rd to SR-202L Pecos Stack

LEGEND: Existing GP Lane Convert HOV Lane to HOT Lane New GP Lane New HOT Lane New C/D Lane

Candidate DHOV locations include:

o Interstate 10 -

Galveston Street

Carver Road

o Interstate 17 -

Central Avenue

15th Avenue

Van Buren Street

Grand Avenue

Mountain View Road

Paradise Lane

Yorkshire Drive/Utopia Road.

Candidate Direct Connector Ramps:

o Interstate 10 at SR-143/Hohokam Expressway (westbound to northbound and southbound to eastbound)

o “The Split” – Interstate 10 westbound to Interstate 17 northbound (west) and Interstate 17 southbound (east) to

Interstate 10 eastbound

o Interstate 17 at SR-101L (Agua Fria Freeway) – “North Stack” (eastbound to southbound and northbound to

westbound).

Candidate Two-Lane (Choice Lane) exit ramps along Interstate 10 Westbound:

o Ray Road

o Warner Road

o Elliot Road

o Broadway Road

o SR-143 and 40th Street.

Candidate Two-Lane (Choice Lane) exit ramps along Interstate 10 Eastbound:

o 32nd Street

o 40th Street

o Elliot Road

o Warner Road

o Ray Road

o Chandler Boulevard.



August, 2013

o

Candidate Two-Lane (Choice Lane) exit ramps along Interstate 17 Northbound:

o Indian School Road

o Camelback Road

o Bethany Home Road

o Peoria Avenue

o Union Hills Drive.

Candidate Two-Lane (Choice Lane) exit ramps along Interstate 17 Southbound:

o Peoria Avenue

o Bethany Home Road

o Camelback Road

o Thomas Road.

Active Traffic Management Measures, such as variable speed limits and improved ramp metering.

Braiding the westbound Baseline Road on-ramp and US-60 exit ramp.

Table 4-4 represents high-level preliminary construction costs based on the improvements described above. The total

estimate cost of the three separate potential improvement segments is $1,951,514,000. The estimate does not include any

costs associated with possible right-of-way acquisition and/or relocations. Also, this estimate does not include a contingency

factor of 30 percent, generally added to ADOT project cost estimates. The ADOT contingency roughly equate to

$59 million. The costs shown in Table 4-4 are stated in 2012 dollars with no escalation for inflation.

TABLE 4-4

ALTERNATIVE 2 – EXPRESS LANES CONCEPT HIGH-LEVEL PROBABLE CONSTRUCTION COSTS

Major Item Description

Potential Interstate 17/Interstate 10 Spine Segment

SR-101L to

McDowell McDowell to Baseline

Baseline to

SR-202L

Earthwork $ 28,083,000 $ 34,244,000 $ 8,112,000

Base and Surface Treatment $ 66,816,000 $ 98,352,000 $ 12,934,000

Drainage $ 28,240,000 $ 29,400,000 $ 10,660,000

Structures $ 168,691,000 $ 199,085,000 $ 13,937,000

Traffic $ 56,150,000 $ 60,375,000 $ 21,488,000

Roadside Development $ 6,354,000 $ 6,615,000 $ 2,399,000

Incidentals $ 373,672,000 $ 451,433,000 $ 73,325,000

Other Project Costs

Utility Relocations (1%) $ 7,280,000 $ 8,795,000 $ 1,429,000

Pavement Incentives (3.5% of Pvmt) $ 2,339,000 $ 3,442,000 $ 453,000

Design Engineering (10%) $ 73,763,000 $ 89,174,000 $ 14,474,000

TOTAL $ 811,388,000 $ 980,915,000 $ 159,211,000

NOTE: A contingency factor of 30 percent, generally added to ADOT total project cost estimates has not been included. The ADOT

contingency roughly equates to $59 million.

FIGURE 4-5

EXPRESS LANES CONCEPT: CANDIDATE LOCATIONS FOR DDIS AND DHOVS

Express Lanes Concept Improvements

Candidate DDI Conversion Location

Candidate DHOV Locations



August, 2013

5.0 Workshop On October 31, 2012, Maricopa Association of Governments (MAG) held a workshop, facilitated by Wilson & Company, to

address concepts and future plans for developing and expanding both Interstate 10 and Interstate 17. The following is a

summary of the proceedings from this workshop that was attended by representatives from the following agencies:

Arizona Department of Transportation

Federal Highway Administration – Arizona Division

City of Phoenix – Streets Department

City of Phoenix – Aviation Department

City of Phoenix – Transit Department

City of Tempe

City of Chandler

Valley Metro/Regional Public Transportation Authority.

Copies of the agenda, handouts, and sign in sheets are provided in the Appendix.

1.1 Workshop Purpose and Objectives The primary objective of the workshop was to build

consensus for the path forward in developing a vision

and conceptual master plan for improvements to (1)

Interstate 10 from the “Pecos Stack”to its junction with

Interstate 17 at “The Split” system interchange, and (2)

Interstate 17 from “The Split” to the “North Stack.”

These segments of the two freeways have been

recognized locally as The Spine Corridor. Ultimately,

the long-range vision must adhere to regional goals,

which must first be defined in the context of The Spine

Corridor.

Traditionally, a primary goal has been identification of

necessary improvements to achieve acceptable levels of

service in area corridors. However, previous study

efforts have resulted in proposals that are not fiscally

achievable, given current RTP funding levels and expected future funding levels. Furthermore, proposed improvements at

“The Split” system interchange do not conform to FAA airspace requirements established for Runway 7R/25L at Phoenix

Sky Harbor International Airport. Therefore, it may be necessary to redefine goals with respect to improvements in these

two critical freeway corridors to develop an implementable, cost-effective solution. In addition to defining and adopting a

long-range vision for The Spine Corridor, it also will be necessary to define an achievable, prioritized, and phased

implementation program and, thereby, create an integrated Conceptual Master Plan. Each of these objectives must be

considered as alternative solutions are developed and evaluated.

Workshop Guiding Principles for Alternatives Development

When building consensus for a conceptual master plan for The Spine Corridor, there are several guiding principles that must

be considered to ensure stakeholder and public acceptance of the proposed master plan and related implementation

strategies.

First and foremost is the need to address public anticipation and sensitivity. The expiration of Proposition 400 is growing

nearer, and the public deserves improvements for the taxes they have paid. If an implementation plan is not developed to

ensure timely and expedited project delivery, public skepticism may undermine future revenue initiatives. A potential strategy

for a customer-focused approach may be to brand and promote future initiatives for The Spine Corridor.

In order to make the best use of Proposition 400 funds and garner public support for future revenue initiatives, proposed

solutions must be feasible to construct with available budget and also ensure the lowest possible future operations and

maintenance costs. There are several operations solutions that could be readily incorporated at relatively low cost, including

dynamic and active traffic management, ITS, direct access for HOV lanes and/or express lanes. Maintenance must be easy,

efficient, and cost-effective.

Of course, proposed improvements must also optimize network safety and performance to the greatest extent feasible with

available funding sources. Performance of transportation systems and services introduced in The Spine Corridor is vital to

the region’s economic vitality. Performance can be defined not only in terms of vehicular travel through the corridor, but

also in terms of opportunities to enhance alternate travel modes. Multimodal solutions need to be considered and must be

included as integral to improving transportation efficiency and effectiveness in The Spine Corridor. The ultimate goal is to

provide travel choices and reliability relative to both freeway facilities forming The Spine Corridors as well as any parallel or

connecting corridors.

It will also be necessary during development of alternatives to consider potential environmental effects of proposed

solutions. As the path forward for development of solutions in The Spine Corridor is defined, strategies should rely to the

greatest extent possible on environmental data already assembled in conjunction with the two freeway corridor studies and

DEISs accomplished by ADOT. This will ensure continuity in approach and speed project delivery.

Ultimately, a policy will need to be developed to address future improvements within The Spine Corridor. This policy should

build on existing policies, where available, and identify gaps in those current policies.

5.1 Example Projects The workshop included discussion of successful examples of similar corridor improvement projects in the United States that

were financially challenged and had major design constraints.

5.1.1. Interstate64/US-40, St. Louis, Missouri

Missouri DOT (MoDOT) officially launched

“The New Interstate 64” project in 2000.

MoDOT used findings from the 1997 Major

Transportation Investment Analysis (MTIA),

conducted by the East-West Gateway Council

of Governments (EWGCOG) and approved

by the Board approved in 1997, as the starting

point for the project.

The MTIA report identified transportation

problems along Interstate 64 and

Interstate 170 and pinpointed concerns related

to neighborhood impacts, funding, safety and

security, air quality, and noise. The report



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included broad recommendations to reconstruct Interstate 64, along with proposals to improve specific interchanges along

the route. It also recommended the location of future MetroLink alignments, (including the Shrewsbury Line that opened in

August 2006), reconstruction of Interstate 64's pavement and bridges, improvement to interchanges, and addition of one lane

in each direction from Interstate 270 to Interstate 170 (not east of Interstate 170). and not extending Interstate 170 south of

Interstate 64.

The results of this study were used by EWGCOG to program federal transportation funding for the Interstate 64

improvement project. The initial project cost estimate of $2.5 billion was rejected by EWGCOG. MoDOT engaged the

engineering and construction industry in a dialogue to encourage them to find solutions with a substantially reduced budget.

In July 2005, The revised Interstate 64 project was funded by EWGCOG at a budget of $535 million. The final approved

project included:

Rebuilding and upgrading all pavement, bridges, and interchanges between Spoede Road in St. Louis County and

Kingshighway Boulevard in St. Louis City.

New high quality connection between Interstate 64 and Interstate 170.

Addition of one lane in each direction between Spoede Road and Interstate 170.

Increasing traffic flow through better design, by eliminating short, tight entrance/exit ramps and merges, and adding

dedicated exit lanes.

5.1.2. Interstate 495 Capital Beltway, Washington, DC

This project involved rehabilitation and reconstruction of the circumferential freeway serving the Washington, D.C. area,

which connects with many radial high-capacity highways, such as Interstate 270, US-29, Interstate 95, Interstate 295, and

US-50. Initial studies by both the Virginia and Maryland Departments of Transportation indicated the need for more

capacity, due to the expanding Washington, DC suburbs and the need for regional access into the Washington DC

metropolitan complex.

The Interstate 495/Capital Beltway provides an important highway link to many of the region's other transportation services

including:

Three regional airports –

Baltimore-Washington International, Reagan

National, and Dulles;

Transit/rail facilities – Washington

Metropolitan Area Transit Authroity (WMATA)

Metrorail and Metrobus services and the Maryland

Rail Commuter (MARC) service; and

Port terminals.

Because of the extensive linkages with other

transportation facilities in the region, severe traffic

congestion on the Capital Beltway has cumulative

effects on regional mobility. In addition, projected

increases in population and employment will place

considerable additional pressure on the regional

transportation network to provide adequate

accessibility between suburban residential and business communities. Current traffic volumes exceed 200,000 vehicles per

day in some sections and traffic volumes are projected to increase to about 250,000 vehicles per day by 2030.

Understanding that total project costs could not be funded by Virginia and Maryland DOT’s, it was concluded that the

addition of new capacity on the beltway would require another funding source: the two DOTs turned to private investment

(P3) opportunities and tolling. In exchange for an 85-year P3 concession, tolled Managed Lanes are being added to the

Capital Beltway to help offset costs of the freeway rehabilitation project.

5.1.3. Interstate 15 Corridor, Salt Lake City, Utah

Reconstruction of Interstate 15 was the first design-build procurement initiated by the Utah Department of Transportation

(UDOT). The project involved reconstruction of 16.2 miles of the Interstate’s mainline and addition of new general purpose

and HOV lanes through the Salt Lake City metropolitan area. The project also included: construction or reconstruction of

more than 130 bridges; reconstruction of seven urban interchanges; and reconstruction of three major junctions with other

Interstate routes, including Interstate 80 and Interstate 215. In addition, the project provided for construction of an

extensive region-wide advanced traffic management system.

UDOT's decision to use the design-build procurement process was

motivated by two factors. The first was strong public support for

completing the project as soon as possible to minimize the period of

severe traffic congestion resulting from diversion of more than half of

the traffic from Interstate 15 during the construction period. The

second factor was the need to have the project completed before the

2002 Winter Olympics scheduled to be held in Salt Lake City.

It generally was accepted that use of the design-build procurement

process was the only way to satisfy these goals. The design-build

approach relieved UDOT of many problems associated with the

coordination of the design and construction of multiple individual

projects in a congested urban setting. State procurement laws were

modified to clearly authorize UDOT to employ the design-build

procurement process for contracting. This permitted the awarding of

a contract to a firm that provided the "best value" proposal to the

State, even if another firm bid a lower initial cost. The Interstate 15

design-build contract included provisions for payments of up to $50

million in incentive bonuses for timely performance, quality of work,

complying with project management requirements, community

relations, and maintenance of traffic.

While this approach was attractive to the project owner – UDOT, it

created problems for potential contractors, who were not accustomed to bidding for work that included the performance of

required maintenance of the facility for up to 25 years. When efforts to sufficiently raise the comfort level of the proposers

failed, the maintenance period was reduced to a maximum of 10 years – an initial five-year maintenance option and five one-

year renewable options covering years six through 10. Maintenance requirements and standards were restricted to pavement

surfaces, structures, and drainage facilities and did not include any routine maintenance activities.



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5.1.4. Interstate 5/Columbia River Crossing, Portland, Oregon

This proposed bridge replacement project will include additional lanes for enhanced traffic operations (merging movements)

and two LRT tracks. Specific elements of the project are:

Three through-lanes in each direction on a segment of Interstate 5;

A phased LRT loop in Clark County;

An additional span or a replacement bridge for crossing of the Columbia River, with up to two additional lanes for

merging and two LRT tracks;

Interchange improvements;

Capacity improvements for rail freight operations; and

Bi-state coordination of land use and management of the transportation system to reduce demand

These proposed improvements will help eliminate severe congestion problems that have plagued the region. Four to six

hours of congestion occurs daily, a condition forecast to grow to 15 hours per day by 2030. Congestion makes travel time

unreliable and increases both social and commercial

costs. A major contributor to congestion is the

operation of a lift bridge – 459 lifts occurred per year

on average over the last five years. Bridge lifts cause

traffic to stop for up to 20 minutes and the resulting

backup can take hours to clear. Congestion, due to

bridge lifts, collisions, and other causes, results in some

drivers cutting through neighborhoods on local roads,

which creates traffic and safety problems.

With regard to safety, about one crash per day occurs

on the highway, due to closely spaced interchanges,

merging and weaving, and poor sight lines. Crashes

increase significantly with congestion, and collisions

are projected to increase to 750 per year by 2030.

During bridge lifts, there is a three to four fold

increase in the occurrence of crashes. In addition, the existing Interstate 5 Bridge does not have safety shoulders or room to

move disabled vehicles out of the traffic flow.

Key success factors supporting this project are bi-state/multi-municipal cooperation and discussions on the final bridge

height. The bridge height must balance a number of varied interests and concerns, among them: river users; freight mobility;

flight paths over the bridge to Portland International Airport and Pearson Airfield; connections to downtown Vancouver;

and cost and schedule of the project. Changes in the character of

river traffic in the past two years led some river users to request a

bridge taller than the proposed design height of approximately

95 feet. As part of the Columbia River Crossing project’s

ongoing work to prepare a bridge permit application for the

replacement bridge, project staff conducted further analysis of a mid-

range (95 to 110-foot) bridge identified in the Locally Preferred

Alternative. In addition, staff completed new analyses of the

feasibility of 115-, 120-, and 125-foot bridge options. The analyses

considered river use, vessel impacts, freight mobility, highway safety and efficiency, transit efficiency, landside impacts, air

safety, economic impacts and costs associated with various bridge heights.

According to the project Web site, columbiarivercrossing.org, a Record of Decision (ROD) has been awarded, and the states

are actively seeking funding. Officials overseeing the Interstate 5/Columbia River Crossing project are targeting funding

from three major sources: Federal government (FHWA for bridge and highway funds and the Federal Transit

Administration (FTA) for the LRT tracks), states of Washington and Oregon, and toll revenue associated with utilization of

the new Interstate 5 bridge. The project planning, engineering, and contracting staffs continue to coordinate with the

Oregon and Washington state legislatures, state transportation commissions, and federal agencies regarding the availability

and feasibility of tapping identified funding sources. Project staff will continue to refine the project’s financial plan to reflect

the amount and timing of both state and federal funding contributions to the project. The Web site notes there is additional

work needed “…to establish the toll rate setting process, the timing of pre-completion tolling and to test base toll rate

assumptions.” An investment-grade financial analysis must be completed prior to the issuance of bonds to finance the

bridge, the construction of which that will be supported, in part, by toll revenue. A Request for Proposals to complete this

analysis to evaluate forecasted traffic levels and projected toll revenue was jointly issued in the summer of 2012 by the two

states.

5.2 Workshop Discussion Items Throughout the presentation of the two initial ideas for the corridor, the group offered discussion and guidance on several

items. Details regarding specific issues are available for review in the Appendix. Key elements of the discussion, as

summarized below, were influential in later discussions of the vision and path forward for The Spine Corridor.

5.2.1. Consensus

Evident throughout the workshop was concern over building consensus on the vision and path forward for improving The

Spine Corridor. FHWA officials expressed concern regarding public perception, particularly for the Interstate 10 portion of

The Spine Corridor. After ten years of executing the planning, preliminary engineering, and environmental studies, the

public may be concerned about a new direction for the corridor. The group, as a whole, concurred that a long-term vision

would be beneficial. However, there was concern regarding the need to revisit the environmental review process, as this

might retard implementation of some near-term

improvements that could provide assurance to the

public that some progress was being made to improve

the corridor. The group also concurred that it would be

important to prioritize the constraints and objectives in

order to assist in identification and prioritization of

near-term, spot improvements.

5.2.2. Objectives

Discussions addressed whether the process should look

to other measures of effectiveness rather than focusing

on level of service (LOS) goals when determining the

vision for The Spine Corridor. For example, if only

spot improvements were implemented, versus actual

capacity enhancements, would these actions increase

people’s use of alternate modes? Other potential

measures suggested for consideration to improve travel

http://www.columbiarivercrossing.org/FileLibrary/BridgeWorkplan2012.pdf



August, 2013

in the corridor included: lane restrictions for freight, improving the local roadway network to complement the freeway

system, and implementing DHOV improvements at appropriate places.

5.3 Alternative Ideas/Concepts Development Prior to generation of additional alternative ideas or concepts for improving The Spine Corridor, the workshop participants

were presented three questions and asked to respond to them as residents of the Valley rather than as representatives of their

agency.

Do we simply identify a spot improvement (through 2016) strategy?

Do we consider a near-term (through 2026) strategy to spend what is in the RTP?

Do we need a longer-term vision (improvements over a 30-year period) for The Spine Corridor?

Participants provided a variety of answers to these questions and responses were thoroughly discussed. Eventually,

workshop participants reached a consensus that all three questions must be addressed, because they are dependent on one

another. Therefore, it would be necessary to examine each condition and the interactions between conditions to be fiscally

responsible, assure the economic vitality of the region, and provide for the future transportation needs of the traveling public.

Details regarding the various responses to these questions are provided in the Appendix.

Following the discussion of responses to the questions above, a fourth question was posed: “What do we do now?” The

subsequent discussions and conclusions revolved around several topics, as summarized below.

5.3.1. Spend the Available Money

There is approximately $648.5 million of Proposition 400 funding set aside for improvements to the Interstate 10 corridor

and $821.6 million for improvements to the Interstate 17 corridor. Workshop participants agreed that improvement projects

must be initiated and completed to maintain public support for any future extension of the countywide transportation excise

tax. Several potential options were identified to allocate these funds, including:

Reconstruct “The Split” system interchange;

Reconstruct Interstate 17 from “The Split” system interchange to “The Stack” system interchange;

Reconstruct Interstate 10 between SR-143 (Hohokam Expressway) and US-60 (Superstition Freeway) – the

Broadway Curve;

Construct one additional GP lane from the “Pecos Stack” system interchange to ”The Split” system interchange;

Construct new DHOV traffic interchanges;

Reconstruct existing diamond interchanges to DDIs, where appropriate, to improve the efficiency of traffic flows;

Reconstruct the freeway mainline to provide Choice Lane Exit ramps; and

Implement Active Traffic Management Strategies.

The list above demonstrates there clearly is a wide range of options that could be implemented as “spot” improvements.

However, the complexity and cost of each strategy varies greatly. Therefore, it was concluded that it would be necessary to

define the ultimate vision for The Spine Corridor, then develop a prioritized implementation strategy based on the ultimate

vision and adopted path forward.

5.3.2. Should the Long-Term Vision have a “Cap” on the Roadway Footprint?

Workshop participants discussed the feasibility of and potential benefits associated with “capping” the roadway horizontal

alignment) for The Spine Corridor, although various options for utilizing the “capped” footprint potentially footprint. The

primary objective of this concept would be to establish a maximum geometric footprint defining the ultimate extent of the

cross-section available for all roadway elements, such as: additional general purpose lanes, additional HOV lanes, new

express or managed lanes, and new collector/distributor lanes. Workshop participants agreed that a “cap the footprint”

strategy represented a reasonable concept that should be evaluated when considering options for improving freeway system

capacity. However, this concept ultimately must be compared to other reasonable strategies through comprehensive

alternative analysis before it can be established as the most appropriate solution.

5.3.3. Airport Access

Regardless of the selected path forward, the majority of the workshop participants concurred with the need to ensure good

ingress and egress to the airport, as it is a primary economic engine in the MAG region.

5.3.4. Near-Term Improvements

Discussions by the workshop participants also addressed potential near-term improvement options. Near-term

improvements would serve to assure the public that progress is begin made to improve the efficiency and safety of the

Interstate 10 and Interstate 17 corridors, as promised when voters ratified Proposition 400. Options identified as potential

near-term improvements, which would be quickly implemented while additional studies are completed for larger projects,

include:

Improve traffic operations through reassignment of lanes or new construction – an example of the latter would be to

eliminate direct entry of southbound SR 143/Hohokam Expressway traffic on to Intestate 10 within the Broadway

curve by extending the on-ramp south along the west side of the freeway to the US -60 (Superstition Freeway)

system interchange, which would eliminate the weave with eastbound (south) Interstate 10 traffic accessing the

Direct Connector Ramps to eastbound US-60 (Note: the extended ramp would permit access to US-60 eastbound);

Intelligent Transportation Systems (ITS) Measures – possibly a regionalized Traffic Operations Center (TOC) that

integrates ADOT freeway management functions with ITS functions of cities traversed by Interstate 10 and

Interstate 17 traverse;

ADOT officials also noted that improvements to Pinnacle Peak Road and Happy Valley Road traffic interchanges

with Interstate 17 just north of SR-101L (Agua Fria/Pima Freeway) are being considered.

Workshop participants agreed that sufficient study must be accomplished to assure there is a defensible rationale for any spot

improvements selected for implementation.

5.4 Summary of Alternatives Review The workshop concluded with a summary of pertinent items discussed and conclusions reached. It culminated in a

presentation to executives present from MAG, FHWA, and ADOT. The workshop resulted in a consensus of participants

regarding recommended next steps – the path forward for defining the long-term vision for The Spine Corridor and

developing a feasible Conceptual Master Plan.

The first step forward will be identification and prioritization of viable spot improvements projects with specific attention to

pinch points and bottlenecks. This action would facilitate early identification of effective measures for near-term

implementation, illustrate to the public that progress is being made to improve travel in The Spine Corridor.

Based on the earlier discussions, it was agreed that a policy should be established to “cap the footprint.” In order to adopt

this policy, a justification study would be needed. Such a study could include review of peer cities that have implemented

similar policies, such as Seattle, Denver, and Minneapolis. In order to garner support for the policy, it would also be



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necessary to illustrate the benefits of “capped footprints,” such as minimizing the loss of property which affects the economy

and reduces the tax base.

Once the justification study is complete and recommendations for the “capped footprint” are identified and approved, an

amendment to the RTP would be required. Following adoption of the policy to “cap the footprint,” environmental analyses

of future corridor improvements could resume. The publically-vetted policy to “cap the footprint” is a necessary aspect of

the environmental analyses, as the policy would be referenced as an alternative to building improvements that would solve

congestion issues in the corridor. This is to say, the policy and the justification study would provide the rationale for defining

a bundle of improvements that can be implemented within the adopted footprint; however, the restrictions on improvements

would reduce but not fully accommodate forecasted traffic volumes and attendant congestion.

The recommended path forward begins with ADOT officially rescinding the current products of the DEIS/Section 4(f)

Evaluation undertaken in support of the freeway corridor studies that focused on Interstate 10 and Interstate 17. Then, The

Spine Corridor would be segmented for purposes of further analyses. The group recommended logical termini be identified

as follows:

Interstate 17 at SR-101L (Agua Fria/Pima Freeway) to McDowell Road – an Environmental Assessment (EA) is

recommended for this segment;

Interstate 17/McDowell Road to Interstate 10/Baseline Road – a DEIS is recommended for this segment; and

Interstate 10/Baseline Road to Interstate 10 at SR-202L (Santan/South Mountain Freeway) – an EA is

recommended for this segment.

Further discussion occurred regarding options for the current DEIS/Section 4(f) Evaluation effort related to the Interstate

17 Freeway Corridor Improvement Study. Workshop participants identified two options: (1) rescind the current effort and

re-file with new limits or (2) re-file as an EA with new limits. All of the new EAs would rely heavily on work previously

completed for the two DEISs, thereby minimizing the effort typically required for commencing a new environmental

process. Simultaneous with restarting the environmental analyses and DEIS/Section 4(f) Evaluation process, a Conceptual

Master Plan for The Spine Corridor would be developed. Findings and recommendations from this Conceptual Master Plan

then would be incorporated in the next update of the MAG RTP.

Workshop participants also agreed the following resources would be necessary to ensure successful execution of the path

forward:

1. MAG Regional Council;

2. Executive Working Group (ADOT, MAG, FHWA, Cities of Phoenix, Tempe, Chandler, Guadalupe); and

3. Technical Team.



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6.0 Recommendations for Path Forward Following the workshop, a presentation was made to executives from MAG, FHWA, and ADOT. The presentation

highlighted the consensus-based approach established by workshop participants. The following provides the content of the

proposed approach.

1.1 Path Forward: Institutional Arrangements for Spine Oversight Workshop participants recommended the following arrangements be made to ensure necessary support for development of

the Spine Master Plan:

Corridor Charter;

Executive Working Group;

Spine Technical Partners; and

Multimodal Coordination.

6.1.1. “Cap the Footprint”

As presented above, a policy to “cap the footprint” was considered to be a reasonable option for addressing issues associated

with improving the freeway system while minimizing potential impacts. It was recognized that such an option would be

required to justify subsequent improvement recommendations that would not entirely alleviate forecast congestion in the

corridor. Nevertheless, this concept ultimately must be compared to other reasonable strategies through comprehensive

alternative analysis before it can be established as the most appropriate solution. Successful development of this policy

would require several elements, including:

Peer review of best practices;

Definition of the footprint;

Environmental streamlining;

Illustration of the benefits related to the “capping of the footprint;” and

Policy recommendation from Regional Council.

Proposed corridor segmentation with regard to subsequent environmental review processes, as outlined above, was shared

with the Executives.

6.1.2. Potential Near-term Improvements

In addition to development of a policy to “cap the footprint,” workshop participants recommended that near-term “spot

improvements” also be investigated and prioritized. Implementation of near-term projects would illustrate to the public that

progress is being in identifying projects and allocating Proposition 400 funding approved by the voters. Potential near-term

“spot improvements” that may be considered include:

Development of an ATM Master Plan and Policy;

Constructing new DHOV traffic interchanges and related transit enhancements;

Construction of SR-143 Interim Ramps;

Interchange Improvements, such as conversion of existing diamond interchanges to DDIs to improve traffic flow

efficiency;

Construction of two-lane exit ramps at appropriate locations in The Spine Corridor;

Adding one general purpose lane from Interstate 17/SR-101L (Agua Fria/Pima Freeway), “North Stack” system

interchange, to Interstate 17/McDowell Rd and from Interstate 10/Baseline Rd to Interstate 10/SR-202L

(Santan/South Mountain Freeway), “Pecos Stack” system interchange;

Reconfiguring SR-143/Hohokam Expressway access to Interstate 10 to eliminate the weave with eastbound

Interstate 10 traffic accessing eastbound US-60;

Reconstructing Interstate 17 from McDowell Rd to “The Split” system interchange.

6.2 Next steps Based on the recommended path forward, workshop participants agreed on an outline for near-term steps to achieve

identified objectives in The Spine Corridor.

6.2.1. Footprint Definition

The defined footprint for The Spine Corridor would correspond to the adopted long-term vision and provide the foundation

for formulating a policy to “cap the footprint.”

6.2.2. Project Evaluations

Spot improvements could be considered over the following two to three months to identify more immediate, lower cost

solutions for enhancing travel in the corridor. Potential near-term “spot improvements,” presented above, likely would

require a four- to eight-month evaluation period.

6.2.3. Environmental Studies

Once a policy for “capping the footprint” has been fully reviewed approved, subsequent environmental analyses for

identified corridor segments, as discussed above, could commence. As there is substantial information already available for

the prior DEIS/Section 4(f) Evaluation efforts, it is estimated that these studies could be completed in fewer than 36

months.

6.2.4. Programming

All resulting recommendations could then be programmed for construction based on the implementation timeframes

established with each study effort.

technical memorandum: interstate 10 and interstate 17 â€œspine

Documents