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King County Metro

Columbia Street Transit Priority Improvements Alternative Analysis

Downtown Southend Transit Study

May 2014

Parametrix

Columbia Street Transit Priority Improvements Alternative Analysis Downtown Southend Pathways i May 2014

Table of Contents

Introduction .............................................................................................................. 1

Methodology ............................................................................................................. 1

Study Area ................................................................................................... 1

Traffic Volume and Roadway Assumptions ................................................. 2

Transit Service Assumptions ....................................................................... 3

Traffic Operations Models ........................................................................... 3

Existing Conditions .................................................................................................... 4

Existing Roadway Configuration .................................................................. 4

Existing Transit Operations.......................................................................... 5

Existing Intersection Operations ................................................................. 5

Options Evaluated ..................................................................................................... 8

Without the Proposed Project .................................................................... 8

With the Proposed Project .......................................................................... 9

Future Analysis ........................................................................................................ 12

Operational Analysis .................................................................................. 12

Without the Project ................................................................................... 12

With the Project ........................................................................................ 12

Driveway, Alley, and Off‐Street Loading Zone Access .............................. 20

On‐Street Parking ...................................................................................... 22

Pedestrian Facilities ................................................................................... 22

Summary of Findings ............................................................................................... 23

References ............................................................................................................... 24

Columbia Street Transit Priority Improvements Alternative Analysis Downtown Southend Pathways ii May 2014

List of Figures Figure 1. Study Area ......................................................................................................... 2

Figure 2. Columbia Street Existing Roadway Configuration ..................................... 5

Figure 3. Existing Year A.M. Peak Hour Intersection Level of Service .................. 6

Figure 4. Existing Year P.M. Peak Hour Intersection LOS ....................................... 6

Figure 5. Existing Year A.M. Peak Hour 95th Percentile Queues ............................. 7

Figure 6. Existing Year P.M. Peak Hour 95th Percentile Queues ............................. 8

Figure 9. Future Year A.M. Peak Hour HCM Intersection Level of Service

(Synchro) – Without Project, Option 1, Option 2 and Option 2 –

Transit Only .................................................................................................... 14

Figure 10. Future Year P.M. Peak Hour HCM Intersection Level of Service

(Synchro) – Without Project, Option 1, Option 2 and Option 2 –

Transit Only .................................................................................................... 15

Figure 11. Future Year a.m. Peak Hour 95th Percentile Queues (VISSIM) –

Without Project, Option 1, Option 2 and Option 2 – Transit Only ..... 16

Figure 12. Future Year P.M. Peak Hour 95th Percentile Queues (VISSIM) –

Without Project, Option 1, Option 2 and Option 2 – Transit Only ..... 17

Figure 13. General Purpose and Transit A.M. Peak Hour Travel Times -minutes

(VISSIM) – Without Project, Option 1, Option 2 and Option 2 –

Transit Only .................................................................................................... 18

Figure 14. General Purpose and Transit P.M. Peak Hour Travel Times - minutes

(VISSIM) – Without Project, Option 1, Option 2 and Option 2 –

Transit Only .................................................................................................... 19

Figure 15. Driveway, Alley, and Loading Zone Detail – Option 2........................... 21

List of Tables Table 1. Future Year Options .................................................................................. 11

Table 2. Driveway Delays (seconds) ....................................................................... 22

Table 3. Future Year Options Performance Measures ........................................... 23

Columbia Street Transit Priority Improvements Alternative Analysis Downtown Southend Pathways iii May 2014

List of Appendices A Traffic Volume Forecasts

B Intersection LOS and Delay

C Building Owner Concerns

Columbia Street Transit Priority Improvements Alternative Analysis Downtown Southend Pathways 1 May 2014

INTRODUCTION King County Metro (Metro) is the largest transit service agency providing bus service in and through downtown Seattle. The removal of the SR 99 Viaduct and reconstruction of Alaskan Way as part of the Waterfront Seattle project presented the need for evaluating new transit service pathways for bus service connections to West Seattle, Delridge and South King County. One of the major existing southend pathways uses the SR 99 Viaduct with access along Columbia Street (outbound) and Seneca Street (inbound).

A new pathway along Alaskan Way to support local and express service, including Metro’s RapidRide service to West Seattle is needed. King County Metro has conducted a Southend Pathways study, which evaluated a number of pathways connecting to the 3rd Avenue Transit Spine. The preferred solution is to provide two-way transit operations on Columbia Street and transit only lanes on Alaskan Way. This corridor was selected primarily because it had the fastest and most reliable transit travel time among the options considered. The two-way Columbia Street option also aligned with King County Metro’s goals to provide a high degree of service excellence, transit maneuverability and performance, accessibility, transit coverage, and multimodal connections. This pathway also had a reduced footprint for neighborhood and stakeholder impacts compared to other pathways evaluated.

This report summarizes the traffic analysis for two-way Columbia Street operation. It focuses on the transportation effects of reconfiguring Columbia Street to add an eastbound transit-only contra-flow lane between Alaskan Way and 3rd Avenue, and a westbound transit-only lane between 3rd Avenue and Alaskan Way.

METHODOLOGY This section outlines the methodology and assumptions used to evaluate the project’s effects on transportation operations. This includes the study area, existing and future transportation analyses, impact criteria, and mitigation evaluation.

Study Area To evaluate the effects on the transportation network, the study area includes all intersections on Columbia Street between Alaskan Way and 6th Avenue, and Alaskan Way/Yesler Way intersections. Currently, buses access the SR 99 Viaduct from the ramp at the Columbia Street/1st Avenue intersection, therefore intersections west of 1st Avenue were not evaluated for existing conditions. The study area is shown in Figure 1.


Figure 1. Study Area

Traffic Volume and Roadway Assumptions Existing year (2013) and future year (2030) a.m. and p.m. peak hour traffic volumes were developed for all intersections in the study area using information from the following sources:

The City of Seattle’s Synchro Model (year 2006, p.m. peak hour); The Alaskan Way Viaduct (AWV) Replacement Project Final Environmental Impact Statement (FHWA

et al. 2011) Synchro Models (year 2015 with AWV, and year 2030 toll free, a.m. and p.m. peak hour);

Turning movement counts (year 2009, p.m. peak hour); and, The City of Seattle’s Traffic Flow Data Maps1 (years 2006 – 2011, average annual weekday daily

traffic).

All future year options assume that the SR 99 Viaduct has been removed, and that Columbia Street connects to the reconstructed Alaskan Way. The removal of the SR 99 Viaduct and reconstruction of Alaskan Way


changes traffic patterns on streets connecting to Alaskan Way because more options for accessing the downtown grid are available to drivers compared to today, where vehicles are concentrated to Columbia and Seneca Streets. Through traffic on the SR 99 Viaduct would divert to the new SR 99 tunnel, and local traffic to Downtown Seattle would divert to the reconstructed surface Alaskan Way and other streets in Downtown Seattle. Traffic that currently uses Columbia Street to access the SR 99 Viaduct would divert to the reconstructed surface Alaskan Way or other surface streets in Downtown Seattle.

Traffic volumes on Columbia Street, and the north-south cross streets were assumed to be the same for all future year options. Future traffic volumes for all options assume some traffic diversion from Columbia Street to other east-west streets because of travel pattern changes from the Alaskan Way Viaduct Replacement Project. This is accounted for in the future traffic volumes used in this analysis. Existing and future year traffic volumes are shown in Appendix A.

Transit Service Assumptions Existing transit schedules and routes through the study area are based on King County Metro’s September 2013 service schedule. Columbia Street provides one bus zone at 2nd Avenue that serves routes to West Seattle and Burien; transit routes serving this bus stop include:

RapidRide C Line (all day service) 21 Express (p.m. only service) 55 (p.m. only service) 56 Express (p.m. only service) 57 (p.m. only) 120 (all day service) 125 (all day service)

There are approximately 13 buses per hour during the a.m. peak hour (8 – 9 a.m.) and 31 buses per hour during the p.m. peak hour (4:30 – 5:30 p.m.) serving this bus stop.

The following routes also serve West Seattle and Burien:

37 (p.m. only service) 113 (p.m. only service) 121 (a.m. and p.m. service) 122 (p.m. only service) 123 (p.m. only service)

The above routes operate southbound on 2nd Avenue to Columbia Street and northbound from Seneca Street via 1st Avenue to Virginia Street and Third Avenue, except for Route 37, which operates northbound via 1st Avenue S and 4th Avenue S to 3rd Avenue and southbound via 2nd Avenue to Columbia Street.


In the future year, all of the above mentioned routes were assumed to operate on Columbia Street. Routes for outbound service would remain the same as today. Currently, inbound service uses the Seneca Street ramp, in the future, all inbound service was assumed to operate on the new eastbound transit lane on Columbia Street. In the future year, 40 buses per hour were assumed in the peak direction (a.m. peak inbound, p.m. peak outbound).

Traffic Operations Models VISSIM (Version 5.4) was used to analyze vehicle queues and general purpose vehicle and transit travel times. VISSIM simulates multimodal traffic operations, while accounting for a variety of influences found in urban locations, such as pedestrians, bicyclists, on-street parking, alleys, driveways, and transit stops.

Synchro (Version 8) was used to calculate intersection level of service, and develop signal timing plans for the future year options. Synchro calculates intersection delays based on signal timing and volume to capacity ratios.

The existing condition a.m. and p.m. peak hour VISSIM models were developed and calibrated to match existing volumes and observed vehicle queues. The VISSIM model includes existing transit routes consistent with schedule and route data provided on Metro’s website in September 2013. Each route was modeled separately to account for the effect of multiple buses arriving at a transit stop at the same time. Bicycles, parking vehicles, pedestrians, and vehicles accessing alleys and driveways were also included in the model; however these elements were included primarily to determine their effect on general purpose and transit operations.

The calibrated model was then modified to reflect the future conditions with and without the project, using the optimized signal timing plans developed in Synchro. Intersection level of service and delay, travel times, vehicle queues and delays at alleys and driveways were used to compare the future options.

EXISTING CONDITIONS This section summarizes the existing transportation characteristics within the study area. It describes the existing road network, traffic volumes, bus operations, parking, and includes an assessment of existing roadway and transit performance.

Existing Roadway Configuration Columbia Street is a one-way westbound arterial in the central business district of Seattle connecting from 6th Avenue to the SR 99 Viaduct. East of 3rd Avenue, Columbia Street has three travel lanes with on-street parking and loading zones on both sides of the street (as illustrated on Figure 2). Between 3rd Avenue and 1st Avenue, there are four travel lanes with an exclusive left turn lane provided at 2nd Avenue, and a transit only lane between 3rd Avenue and the SR 99 Viaduct. A transit queue jump signal phase is provided at 2ndAvenue and 1st Avenue along Columbia Street. West of 1st Avenue, transit accesses the SR 99 Viaduct using an elevated ramp. There is a downhill grade of greater than 10 percent on Columbia Street between 6thAvenue and 1st Avenue.


Figure 2. Columbia Street Existing Roadway Configuration

Existing Transit Operations A westbound transit queue jump lane and signal is provided at 2nd Avenue to facilitate buses merging over one lane to the left to access the SR 99 Viaduct at 1st Avenue. Transit queue jumps allow buses to proceed through an intersection (‘get a green light’) before general purpose traffic. A transit only lane and a transit queue jump are also provided at 1st Avenue for situations when congestion on Columbia Street may prevent a bus from changing lanes after the 2nd Avenue queue jump. The transit lane and queue jumps on Columbia Street improve transit speed and reliability in the corridor.

Existing Intersection Operations Intersection operations are reported using a level of service (commonly referred to as LOS) and used to report how well, or poorly, intersections are operating. LOS is expressed as a letter grade from A through F. The letter A indicates the least amount of congestion and best operations; the letter F indicates the highest amount of congestion and worst operations.

The Columbia Street/1st Avenue intersection operates at level of service (LOS) E during the p.m. peak hour, and is the only study intersection that operates worse than LOS D, as illustrated in Figures 3 and 4. See Appendix B for detailed LOS and intersection delay information.


Figure 3. Existing Year A.M. Peak Hour Intersection Level of Service

Figure 4. Existing Year P.M. Peak Hour Intersection LOS


Vehicle queues for the a.m. and p.m. peak hour are shown in Figures 5 and 6. As illustrated in Figure 6, p.m. peak hour queues at some intersections extend back to adjacent intersections. This can temporarily block the intersection until the queued vehicles exit the intersection. When queued vehicles block intersections, delay and travel times increase because vehicles are stopped during a green light waiting for the intersection to clear.

Figure 5. Existing Year A.M. Peak Hour 95th Percentile Queues


Figure 6. Existing Year P.M. Peak Hour 95th Percentile Queues

OPTIONS EVALUATED This section describes the anticipated future year transportation conditions of the study area and summarizes impacts on vehicle and transit operations. Future year conditions without the proposed project were evaluated as well as two options and one sub option. As part of the Waterfront Seattle project, all future options include a new outbound bus zone on westbound Columbia Street between Western Avenue and Alaskan Way, and a new inbound bus zone on northbound Alaskan Way between Yesler Way and Columbia Street. Outbound buses from Seattle would continue to use Columbia Street to access the reconstructed Alaskan Way. Inbound bus routes to Seattle would vary depending on the future option, as described below.

Without the Proposed Project Columbia Street is assumed to be the same as existing conditions east of 2nd Avenue. West of 2nd Avenue, the street would be three lanes with two general purpose lanes and a shared right turn only/transit through lane. The transit queue jumps at 2nd Avenue and 1st Avenue could be evaluated for removal because buses could turn onto southbound Alaskan Way from the curb lane. Inbound buses to Seattle are assumed to be routed to another pathway outside of the study area because the Seneca Street ramp would be removed and Columbia Street would remain one-way westbound. On street parking and loading on Columbia Street is anticipated to be removed west of 1st Avenue to accommodate three westbound travel lanes.


With the Proposed Project The proposed project would create a new eastbound transit only lane on Columbia Street between Alaskan Way and 3rd Avenue. A new bus zone would also be provided on the south side of Columbia Street between 2nd Avenue and 3rd Avenue to serve inbound buses. Two options and one sub option were evaluated, and are shown in Figures 7 and 8 and summarized in Table 1.

Option 1 maintains a 3-lane roadway between 3rd Avenue and Alaskan Way, but converts one westbound general purpose lane to an eastbound transit lane. In the eastbound direction, the transit lane would allow general purpose traffic for local access between 1st Avenue and 2nd Avenue only. General purpose vehicles in this block would be forced to turn right at 2nd Avenue.

Option 2 also converts one westbound general purpose lane to an eastbound transit lane, and general purpose vehicles are allowed in the new eastbound lane for local access between 1st Avenue and 2nd Avenue only. General purpose vehicles in this block would be forced to turn right at 2nd Avenue. Option 2 also provides an exclusive westbound left turn lane at 2nd Avenue, and an exclusive westbound right turn lane at 1st Avenue, creating a 4-lane roadway between 3rd Avenue and 1st Avenue.

The sub option, Option 2 – Transit Only, provides the same lane configuration as Option 2, but general purpose traffic is not allowed in the eastbound transit lane.

Both Option 1 and 2 would require the 3rd Avenue/Columbia Street intersection traffic signal to be modified to add a protected eastbound left turn phase (similar to the existing signal at the 3rd Avenue/Seneca Street intersection).


Table 1. Future Year Options

Option 1 Option 2 Option 2 – Transit Only

General Purpose Traffic

Westbound

East of 4th Avenue – no change compared to conditions without the project West of 4th Avenue – merge to a single through lane, no turn pockets are provided, right turns allowed from transit lane

East of 4th Avenue – the shared through, right turn lane at 4th Avenue would be changed to a right turn only lane West of 4th Avenue – merge to a single through lane, but provide an exclusive left turn lane at 2nd Avenue, and an exclusive right turn lane at 1st Avenue

Same as Option 2

Eastbound

Right turn only at 2nd Avenue Provides increased access to buildings on the south side of Columbia Street between 1st Avenue and 2nd Avenue compared to Option 2 – Transit Only

Same as Option 1

No Access Provides less access to buildings on the south side of Columbia Street between 1st Avenue and 2nd Avenue compared to Options 1 and 2

Transit

Westbound – right turn only/transit through lane between 3rd Avenue and Western Avenue. Transit only lane from Western Avenue to Alaskan Way. Eastbound –transit only lane between Alaskan Way and 3rd Avenue and general purpose right turns allowed at 2nd Avenue

Westbound – the same as Option 1, except for buses shift left one-lane between 2nd and 1st Avenue to go through

Same as Option 1

Westbound - same as Option 2

Eastbound – Transit only lane between Alaskan Way and 3rd Avenue

Alley and Driveway Access

North side of Columbia Street – access would occur from the right turn only/transit through lane (westbound only). Left turns to and from driveways would not be permitted. South side of Columbia Street – westbound vehicles would cross the eastbound transit lane to enter driveways. General purpose vehicles would be allowed to turn right onto eastbound Columbia Street between 1st Avenue and 2nd Avenue only, but would be forced to turn right at 2nd Avenue.

Same as Option 1

Same as Option 1 except no general purpose vehicle access from the south side of Columbia Street to and from the eastbound transit lane


FUTURE ANALYSIS This section describes the operational analysis; driveway, alley, and loading access conditions; parking impacts; and nonmotorized characteristics of the study area with and without the proposed project.

Operational Analysis This section describes the future year intersection operations for all options. LOS for the a.m. and p.m. peak hours are shown in Figures 9 and 10, and detailed intersection LOS and delay are included in Appendix B. Vehicle queues are shown in Figures 11 and 12, and travel times are summarized in Figures 13 and 14. The operational characteristics for each option are described below.

Without the Project All intersections are anticipated to operate at LOS D or better during the a.m. and p.m. peak hours (see Without Project in Figures 9 and 10). During the p.m. peak hour, overall intersection delay at the 1st Avenue and 2nd Avenue intersections improve compared to existing conditions, from LOS D to C and E to C, respectively. This reduction in intersection delay results from lower anticipated volumes on Columbia Street because of other east-west street connections to Alaskan Way. Traffic queues during the a.m. peak hour on Columbia Street are similar to existing conditions west of 3rd Avenue, and slightly longer east of 3rd Avenue (see Without Project in Figures 11 and 12). Traffic queues on the northbound and southbound approaches to Columbia Street increase slightly compared to existing conditions due to the anticipated traffic volume increases.

With the Project As shown in Figures 9 through 14, there is very little operational difference between Option 2 and Option 2 – Transit Only. In the following discussion, references to Option 2 will refer to both Option 2 and Option 2 – Transit Only.

The primary roadway channelization and operational difference between Option 1 and Option 2 is the exclusive left turn lane at 2nd Avenue included in Option 2. Left turning vehicles must yield to high pedestrian crossing volumes, and the exclusive left turn lane in Option 2 prevents left turning vehicles from blocking through vehicles. In Option 1, which provides a shared through/left turn lane at 2nd Avenue, left turning vehicles block through vehicles and increase general purpose traffic delays, queues and travel times are shown in Figures 9 through 14.

Option 2 also provides an exclusive right turn lane at 1st Avenue, which provides a refuge for right-turning vehicles waiting for crossing pedestrians and would not block the transit lane. This refuge also provides space for morning queues from the parking garage entrance off 1st Avenue north of Columbia Street. This parking garage is located outside of the study area, but the exclusive right turn lane in Option 2 prevents the queue from blocking transit, improving bus speed and reliability compared to Option 1.

All intersections are anticipated to operate at LOS D or better in both the a.m. and p.m. peak hours for all options with the exception of the Columbia Street and 2nd Avenue intersection for Options 1 and 2. This is


because of the high traffic volume on the southbound (2nd Avenue) approach and the reduced general purpose lane capacity on Columbia Street compared to without the project.

As shown in Figures 11 and 12, most intersection queue lengths are similar because queues in both options extend to the limits of the modeled study area. When this condition occurs, one method of measuring the difference among the options is evaluating the number of unserved vehicles. This provides a modeled estimate of the number of vehicles queued beyond the modeled study area and is an indication of whether traffic diversion could occur. During the a.m. and p.m. peak hour, Option 1 has more unserved vehicles compared to Option 2. During the a.m. peak hour, Option 1 leaves 1,670 vehicles unserved, compared to 130 with Option 2, and in the p.m. peak hour, Option 1 leaves 840 vehicles unserved compared to 70 with Option 2: It is likely that Option 1 would result in more traffic diversion than Option 2, which could increase delays and travel times on other Downtown Seattle streets.

As shown in Figures 13 and 14, general purpose travel times on Columbia Street are approximately 5 to 9 minutes longer with Option 1 than with Option 2. Transit travel times on Columbia Street are similar between Option 1 and Option 2 and improve by up to a minute compared to without the project. The transit lane on westbound Columbia Street allows buses to avoid the effects of congestion in the general purpose lanes and maintain speed and reliability in both Options.

With the project, intersection level of service is slightly worse than without the project, but all intersections still operate at LOS D or better during both peaks with the exception of the Columbia Street and 2nd Avenue intersection. Queues, and general purpose travel times are also worse than without the project, but the project provides benefits to transit, including better speed and reliability for inbound and outbound buses. Without the project, inbound buses would need to use another pathway to access the 3rd Avenue transit spine. Transit riders would board and alight their buses on different corridors reducing the ease of use and visibility of the transit service. Locating inbound and outbound bus stops on the same street with the project reduces rider confusion.


Figure 9. Future Year A.M. Peak Hour HCM Intersection Level of Service (Synchro) – Without Project, Option 1, Option 2 and Option 2 – Transit Only


Figure 10. Future Year P.M. Peak Hour HCM Intersection Level of Service (Synchro) – Without Project, Option 1, Option 2 and Option 2 – Transit Only


Figure 11. Future Year a.m. Peak Hour 95th Percentile Queues (VISSIM) – Without Project, Option 1, Option 2 and Option 2 – Transit Only


Figure 12. Future Year P.M. Peak Hour 95th Percentile Queues (VISSIM) – Without Project, Option 1, Option 2 and Option 2 – Transit Only


Figure 13. General Purpose and Transit A.M. Peak Hour Travel Times -minutes (VISSIM) – Without Project, Option 1, Option 2 and Option 2 – Transit Only


Figure 14. General Purpose and Transit P.M. Peak Hour Travel Times - minutes (VISSIM) – Without Project, Option 1, Option 2 and Option 2 – Transit Only


Driveway, Alley, and Off-Street Loading Zone Access Columbia Street provides access to driveways, alleys, and off-street loading zones for a number of buildings. Alternatives to these existing access points are limited making it important to maintain this access.

The proposed eastbound transit lane (Options 1 and 2) would affect access to a number of driveways, alleys, and loading zones currently on Columbia Street between 1st Avenue and 3rd Avenue. On the south side of Columbia Street, the new eastbound transit lane would eliminate current loading and parking zones and modify access to alleys at the Millennium Tower, and at 215 Columbia, as illustrated in Figure 15. On the north side of Columbia Street, access to the parking garage and alley at the Seattle Metropolitan Credit Union (SMCU), and to the loading dock at the Norton Building would be the same as today.

Contacted building owners provided comments about the accessibility and operational impacts of the proposed Options: specific concerns from each building owner are included in Appendix C, and summarized as follows:

Accommodate existing and potential future loading zone functions: Options 1 and 2 would remove on-street parking and loading zones between Alaskan Way and 3rd Avenue to accommodate the eastbound and westbound transit lanes. This includes loading zones in front of 215 Columbia and Millennium Tower, and three parking spaces, as illustrated in Figure 15. Loading zones could be evaluated for relocation to other nearby streets.

Maintain Access to Parking Garage Driveways, Alleys, and Off Street Loading Areas: Access to parking garage driveways, alleys, and loading docks on the north side of Columbia Street would remain the same as with existing conditions. Access on the south side of Columbia Street would change, as westbound vehicles, and vehicles exiting garages and alleys, would conflict with buses in the eastbound transit lane (approximately 40 buses per hour during the peak, or 1 bus every 1.5 minutes). A benefit of Option 1 and Option 2 is general purpose vehicles would be able to use eastbound Columbia Street between 1st Avenue and 2nd Avenue for local circulation, but would be required to turn right at 2nd Avenue.

Maintain circulation to I-5 with turn movements at 1st Avenue, 2nd Avenue and 3rd Avenue: Both Options would maintain existing access to 2nd Avenue and 1st Avenue. Option 1 and Option 2 would also allow eastbound right turns for general purpose vehicles at 2nd Avenue.


Figure 15. Driveway, Alley, and Loading Zone Detail – Option 2


Delays at driveways and alleys were worse in Option 1 compared to Option 2, but both options increase delay compared to without the project, as shown in Table 2. The operations at driveways and alleys are difficult to accurately model because driver behavior varies and is impacted by localized traffic conditions. In the VISSIM model, through vehicles on Columbia Street were permitted to yield to vehicles exiting driveways to prevent long queues forming on the driveways – these assumptions were based on observation and engineering judgment.

Table 2 Driveway Delay -seconds (VISSIM)

Existing Year (2013) Without Project Option 1 Option 2 Option 2 –

Transit Only

a.m. peak hour

4th & Columbia Parking In 4 4 60 11 8 Out 19 20 59 26 22

Pacific Building In 6 5 88 13 13 Out 20 23 71 27 24

SMCU Building In 4 5 5 6 6

Out 14 14 45 24 20

Millennium Tower In 3 3 5 6 4 Out 8 10 10 10 11

p.m. peak hour

4th & Columbia Parking In 5 5 47 11 10

Out 28 21 70 24 28

Pacific Building In 6 7 74 16 22

Out 32 24 69 29 27

SMCU Building In 18 12 16 10 9

Out 86 46 103 27 29

Millennium Tower In 4 3 7 8 9

Out 14 11 14 43 55

On-Street Parking Without the project, seven parking spaces, one 3-minute passenger loading zone, and three 30-minute loading zones on the south side of Columbia Street would be removed to accommodate the 3-lane roadway between 2nd Avenue and Alaskan Way as part of the Seattle Waterfront Program. With all Options, three additional parking spaces and one loading zone on the south side of Columbia Street between 2nd Avenue and 1st Avenue would be removed.

Pedestrian Facilities Pedestrian facilities on Columbia Street would remain the same as existing conditions without the project. Bus passengers would access outbound bus service on Columbia Street between 3rd Avenue and 2nd Avenue and inbound bus service on another pathway. Pedestrian facilities west of 1st Avenue would be reconstructed as part of the Waterfront Seattle Program.

With the project, all Options would construct a new bus zone on eastbound Columbia Street between 3rd Avenue and 2nd Avenue. The addition of the eastbound bus zone would improve transit visibility and ease of


use compared to existing conditions because access to inbound and outbound bus service would be on the same street. Option 1 could provide wider sidewalks (4-5 feet wider on each side) between 1st Avenue and 3rd Avenue because the roadway is only three lanes, compared to four lanes with Option 2. The wider sidewalks with Option 1 would improve the pedestrian capacity and comfort, especially at bus zones between 2nd Avenue and 3rd Avenue.

Sidewalk congestion at Columbia Street bus zones is anticipated to be reduced because of the new bus stops provided on Alaskan Way to serve the Pioneer Square area.

With Option 2, the corridor could include improvements to improve the pedestrian environment such as consolidating signs, removing shelters in favor of awnings on buildings, and covering open areaways with new sidewalks where possible.

SUMMARY OF FINDINGS This analysis demonstrates that providing four travel lanes on Columbia Street between 1st Avenue and 3rd Avenue (Option 2) allows for exclusive left turn lanes and provides faster travel times, less delay and less vehicle queuing for general purpose traffic compared to Option 1. Table 3 provides a summary of the results by performance measure.

Table 3. Future Year Options Performance Measures


REFERENCES

1. http://www.seattle.gov/transportation/tfdmaps.htm

APPENDIX A

TRAFFIC VOLUME FORECASTS

Columbia Street Transit Priority Improvements Alternative Analysis Downtown Southend Pathways A-1 May 2014

Existing Year a.m. Peak Hour Traffic Volumes


Existing Year p.m. Peak Hour Traffic Volumes


Future Year a.m. Peak Hour Traffic Volumes


Future Year p.m. Peak Hour Traffic Volumes

APPENDIX B

INTERSECTION LOS AND DELAY (SYNCHRO)

Columbia Street Transit Priority Improvements Alternative Analysis Downtown Southend Pathways B-1 May 2014

Existing Year Intersection HCM LOS and Delay (Synchro) a.m. peak hour p.m. peak hour

LOS Delay (sec/veh) LOS Delay (sec/veh)

Columbia Street and 5th Avenue C 21 B 17

Westbound C 24 B 18

Southbound B 18 B 16

I-5 Express Lane Ramp D 40 - -

Columbia Street and 4th Avenue B 19 B 16

Westbound C 29 B 19

Northbound B 15 B 14

Columbia Street and 3rd Avenue B 12 B 13

Westbound B 11 B 15

Northbound A 8 A 8

Southbound B 17 A 8

Columbia Street and 2nd Avenue A 8 D 45

Westbound B 12 F 107

Southbound A 7 A 9

Columbia Street and 1st Avenue C 29 E 58

Westbound C 27 C 22

Northbound C 25 B 15

Southbound D 39 F 161

Notes: Approach delay includes general purpose and transit delay

Delay is rounded to the nearest second. In some cases the same delay will have a different LOS, for example, 9.9 seconds of delay (LOS A) and 10.1 seconds of delay (LOS B) will be shown as 10 seconds of delay.


Future Year a.m. Peak Hour Intersection HCM LOS and Delay (Synchro)

Without Project Option 1 Option 2 Option 2 – Transit Only

LOS Delay sec/veh

LOS Delay sec/veh

LOS Delay sec/veh LOS Delay

sec/veh

Columbia Street and 5th Avenue C 28 C 28 C 28 C 28

Westbound C 26 C 26 C 26 C 26

Southbound C 27 C 27 C 27 C 27

I-5 Express Lane Ramp D 40 D 40 D 40 D 40

Columbia Street and 4th Avenue D 51 D 51 D 53 D 53

Westbound C 27 C 27 C 32 C 32

Northbound E 59 E 59 E 59 E 59

Columbia Street and 3rd Avenue A 10 B 14 B 13 B 12

Eastbound - - D 42 D 44 C 35

Westbound A 8 A 9 A 6 A 6

Northbound A 8 B 18 B 18 B 18

Southbound B 16 B 15 B 17 B 17

Columbia Street and 2nd Avenue B 14 F 91 C 29 C 28

Eastbound - - A 9 B 14 A 0

Westbound B 18 F 287 D 41 D 41

Southbound B 12 C 25 C 25 C 25

Columbia Street and 1st Avenue C 22 C 21 C 23 C 24

Eastbound - - A 7 A 4 C 29

Westbound A 8 A 5 A 10 A 10

Northbound C 25 C 26 C 26 C 26

Southbound A 34 C 35 C 35 C 35

Columbia Street and Western Avenue A 10 B 11 B 11 B 12

Eastbound - - B 13 B 13 C 23

Westbound B 10 B 14 B 15 B 16

Northbound A 10 A 9 A 9 A 10

Southbound A 9 A 9 A 9 A 9

Columbia Street and Alaskan Way A 6 A 6 A 6 A 6

Westbound D 35 D 37 D 37 D 38



Alaskan Way and Yesler Way D 50 D 50 D 50 D 50

Eastbound D 44 D 44 D 44 D 44

Westbound F 88 F 88 F 88 F 88

Northbound E 70 E 70 E 70 E 70

Southbound B 13 B 13 B 13 B 13

Notes: - Approach delay includes general purpose and transit delay - Delay is rounded to the nearest second. In some cases the same delay will have a different LOS, for example, 9.9 seconds of delay (LOS A) and

10.1 seconds of delay (LOS B) will be shown as 10 seconds of delay.


Future Year a.m. Peak Hour Intersection HCM LOS and Delay (Synchro)

Without Project Option 1 Option 2 Option 2 – Transit Only

LOS Delay sec/veh

LOS Delay sec/veh

LOS Delay sec/veh LOS Delay

sec/veh

Columbia Street and 5th Avenue C 21 C 21 C 21 C 21

Westbound B 20 B 20 B 20 B 20

Southbound C 21 C 21 C 21 C 21

I-5 Express Lane Ramp - - - - - - Columbia Street and 4th Avenue C 26 C 26 C 29 C 29

Westbound C 22 C 23 D 37 D 37


Columbia Street and 3rd Avenue B 11 D 53 B 12 B 13

Eastbound - - D 50 D 51 D 53

Westbound B 12 E 79 A 5 A 5

Northbound B 13 C 25 C 25 C 25

Southbound A 7 B 14 B 14 B 14

Columbia Street and 2nd Avenue C 22 F 149 E 76 E 77

Eastbound - - A 8 A 9 B 18

Westbound D 37 F 304 D 47 D 47

Southbound B 15 F 91 F 91 F 91

Columbia Street and 1st Avenue C 23 C 34 D 36 D 35

Eastbound - - A 9 A 9 B 16

Westbound A 7 D 50 E 61 E 57


Southbound D 41 D 41 D 41 D 41

Columbia Street and Western Avenue B 12 B 15 B 15 B 15

Eastbound - - B 15 B 15 C 25

Westbound B 15 C 25 C 25 C 24

Northbound B 10 B 10 B 10 B 10


Columbia Street and Alaskan Way A 10 B 17 B 17 B 17

Westbound D 41 F 87 F 87 F 87


Southbound A 9 B 12 B 12 B 12

Alaskan Way and Yesler Way D 44 D 46 D 46 D 46

Eastbound D 39 D 39 D 39 D 39

Westbound E 75 E 75 E 75 E 75

Northbound D 42 D 42 D 42 D 42

Southbound D 45 D 51 D 51 D 51

Notes: - Approach delay includes general purpose and transit delay - Delay is rounded to the nearest second. In some cases the same delay will have a different LOS, for example, 9.9 seconds of delay (LOS A) and

10.1 seconds of delay (LOS B) will be shown as 10 seconds of delay.

APPENDIX C

BUILDING OWNER CONCERNS

Columbia Street Transit Priority Improvements Alternative Analysis Downtown Southend Pathways C-1 May 2014

Summary of Key Issues – Columbia Street Properties

Location Key Issues SEIU Building 215 Columbia Street

1) Continue to accommodate loading and unloading on Columbia Street near building entrance.

2) Passenger drop-off activities are currently occurring on 3rd Avenue. This may be accommodated by a load/unload zone north of the existing Metro bus stop.

Pacific Building 720 Third Avenue

1) Preserve load zone on Columbia Street between 3rd and 4th currently used for daily deliveries.

2) Maintain ingress and egress into Pacific Building garage on Columbia Street between 3rd and 4th Avenues. Access for users to and from I-5.

3) Current back-ups on Columbia Street back up the garage. Allowing a left turn onto 3rd Avenue or other option may help alleviate this.

Seattle Metropolitan Credit Union 801 Third Avenue

1) Preserve left turn from Columbia Street onto 2nd Avenue to allow cars exiting garage to access I-5 and points south.

2) Parking garage queue backs up onto Columbia Street. Norton Building

801 Second Avenue

1) Preserve loading dock access on Columbia Street between 1st and 2nd Avenue.

2) Maintain ingress and egress at parking garage on 1st Avenue. 3) Loading zone on south side of Columbia between 1st and 2nd Avenues is

sometimes used for deliveries at Norton Building. Millennium Tower 715 Second Avenue

1) Conflicts between buses and cars accessing Millennium Tower garage on the south side of Columbia Street, between 1st and 2nd.

2) Change in current traffic patterns for vehicles accessing southbound 1st Avenue from the Millennium Tower.

3) Reduced sightlines that inhibit potential garage users from seeing parking rates or accessing the garage.

4) Safety for pedestrians and drivers including movement of drivers across oncoming traffic and visibility of pedestrians crossing garage or alley entrance.

5) Preservation of on-street loading zone south side on Columbia Street between 1st and 2nd Avenues. Removal of loading to impact truck volumes using the building’s loading dock.

6) Impacts of bus noise on building tenants and effect on lease rates.

king county metro street transit priority improvements ... · columbia street transit priority...

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