office of roadway engineering - ohio department of ......interchange operations study (ios) reports...

Interchange Operations Study (IOS) reports will be submitted to, reviewed, and approved by the Office of Roadway Engineering Projects That Require an IOS (Interchange Operations Study)

• Changing lane configurations at a ramp intersection approach, including: 1. Adding a left or right turn lane along the crossroad 2. Adding a thru lane on the crossroad 3. Adding turn lanes to the exit ramp 4. Changing lane assignments without altering the number of lanes

a. Example: Changing a 2-lane approach from (Left / Thru-Right) to (Left-Thru / Right)

5. Implementing a Road Diet – reducing the number of lanes on the crossroad 6. “Squaring” up a continuous right turn lane from the ramp/crossroad and putting it

thru the signal

• Changing the exit or entrance ramp terminus point with the mainline by: 1. Creating an optional exit lane 2. Creating a 2-lane exit 3. Creating a 2-lane entrance

• Shifting a ramp’s location within the same interchange configuration without changing the ramp type

• Changing traffic control type at the ramp/crossroad intersection: 1. Example: Revising from signalized/unsignalized condition to a roundabout

• Adding an auxiliary lane between two adjacent interchange ramps (preferably less than 1 mile) where the single auxiliary lane does not function as a mainline travel lane

• Altering access between managed lanes and general purpose lanes on the Interstate

For all other modifications to the interchange or mainline that result in significant changes to the operations that are not covered above and do not warrant an Interchange Modification Study, please contact the Office of Roadway Engineering.

03/24/2015 Interchange Operations Study (IOS) - ODOT Office of Roadway Engineering of 13

Analysis Points for:

• IMS (Interchange Modification Study)

• IOS (Interchange Operations Study)

• Comparison of IMS vs. IOS analysis points


Traffic Academy: IJS & IMS

Analysis Points for IMS

Interchange

being studied

Mainline Analysis

**

*

*

Weave Analysis (if applicable)

Merge Analysis

*

Diverge Analysis

½ m

ile½

mileIntersection Analysis

Example #1

Certified Traffic Limits



Analysis Points for IOS (1 Intersection)

Mainline Analysis

*


Merge Analysis

*

Diverge Analysis Next

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Intersection

being modified

Intersection Analysis

Example #1

Certified Traffic LimitsObtain all counts within

limits


Not Required

Next

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Comparison: IMS vs. IOS (Example #1)

Mainline Analysis

*


Merge Analysis

*


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Intersection

being modified


Analysis Points Removed



Analysis Points for IOS (2 Intersections)

Mainline Analysis

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Merge Analysis

*


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Next

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Example #2

Intersection

being modified

Intersection

being modified

Certified Traffic LimitsObtain all counts within

limits


Sample IOS (Interchange Operations Study)


ERI-SR2 & US250 INTERCHANGE OPERATIONS STUDY

Project Summary

Location SR2 & US250 Interchange

near Sandusky, Ohio

Erie County

PID 88407

Study Sponsor ODOT, District 3

Proposed Work Add a WB Rt. @ WB SR2 & US250 Exit Ramp

Study Area

HCS Analysis Points:

Freeway Analysis

• WB SR2, upstream of the US250 Diverge

• WB SR2, downstream of US250 Merge

Ramp Analysis

• WB SR2 Diverge to US250

• WB SR2 Merge from US250


• WB SR2 Ramps & US250

• EB SR2 Ramps & US250

• US250 & Walmart/Applebee’s Intersection

Proposed Improvement:

Add a WB Rt. @WB SR2 &

US250 Ramps



Problem Description

US250 is a major corridor serving various recreational destinations in northern Ohio including

Cedar Point Amusement Park, Kalahari Water Park, Kelleys Island, and Lake Erie. As part

of that corridor, the SR2 & US250 Interchange is a primary access junction to this area.

A recent Safety Study of the US250 Corridor by Mannik & Smith, extending from Bogart Rd.

to US6, identified US250 as a high crash area. One of the proposed strategies recommended

by the Safety Study was to increase capacity at the WB SR2 & US250 exit ramp. This

Interchange Study documents the addition of a 3rd lane on the WB SR2 exit ramp. The existing

WB SR2 exit ramp approach consists of a single lane that opens up to a shared, Thru-Right

lane and an exclusive Left turn bay at the intersection with US250.

Traffic Analysis

Posted Speed Limits (of Roadways within the Study Area):

• Mainline, SR2 – 65 mph

• Crossroad, US250 (Milan Rd.) – 40 mph

• Adjacent Intersection, Park Place/Applebee’s - 25 mph

Freeway Analysis Results:

SR2 WB

Mainline

2036 AM

No-Build

2036 AM

Build

2036 PM

No-Build

2036 PM

Build

LOS Density

(pc/mi/ln)

LOS Density

(pc/mi/ln)

LOS Density

(pc/mi/ln)

LOS Density

(pc/mi/ln)

WB SR2, E. of

US250 Exit

B 17.6 B 17.6 A 5.1 A 5.1

WB SR2, W. of

US250 Entrance

B 13.1 B 13.1 A 5.9 A 5.9

Ramp Analysis Results:

SR2 WB

Ramp

Analysis

2036 AM No-Build 2036 AM Build 2036 PM No-Build 2036 PM Build

LOS Density

(pc/mi/ln)

LOS Density

(pc/mi/ln)

LOS Density

(pc/mi/ln)

LOS Density

(pc/mi/ln)

US250 Diverge C 21.9 C 21.9 A 6.2 A 6.2

US250 Merge C 20.9 C 20.9 A 8.8 A 8.8



Intersection Analysis Results:

US250

Signalized

Intersections

2036 AM

No-Build

2036 AM

Build

2036 PM

No Build

2036 PM

Build

LOS Delay

(sec/veh)

LOS Delay

(sec/veh)

LOS Delay

(sec/veh)

LOS Delay

(sec/veh)

US250& WB SR2 Ramp (using 90 sec cycle) US250& WB SR2 Ramp (using 90 sec cycle)

WB Appoach 24.0 C 21.0 C 44.7 D 32.3 C

NB Approach 11.3 B 14.2 B 9.7 A 12.4 B

SB Approach 23.5 C 21.1 C 44.7 D 32.2 C

Overall

Intersection

18.1 B 18.0 B 32.4 C 25.2 C

US250 & EB SR2 Ramp (using 90 sec cycle) US250 & EB SR2 Ramp (using 110 sec cycle)

EB Approach 15.7 B 14.5 B 20.3 C 19.9 B

NB Approach 15.8 B 15.0 B 20.6 C 17.6 B

SB Approach 12.2 B 13.6 B 19.2 B 19.9 B

Overall

Intersection

14.9 B 14.5 B 20.0 B 19.0 B

US250 & Applebee’s/Park Place (using 90 sec cycle) US250 & Applebee’s /Park Place (using 110

sec cycle)

EB Approach C 24.7 C 24.7 C 31.6 C 24.7

WB Approach C 21.3 C 21.3 D 38.0 C 21.3

NB Approach C 25.1 C 25.1 D 38.9 C 25.1

SB Approach A 9.3 A 9.3 C 27.1 A 9.3

Overall

Intersection

B 19.5 B 19.5 C 33.0 B 19.5



Storage Lengths:

Intersection/Turn

Lane

2038 DHV for

Turn Lane

Required

Turn

Lane

Storage

Potential

Thru

Backup

Existing

Turn

Lane

Length#

Proposed

Turn Lane

Length# AM

veh/hr

PM

veh/hr

US250 & WB SR2

Ramp

90 sec

cycle

110 sec

cycle

WB Lt 50 90 150’ 200’ 315’ 200’

WB Rt. (2 lanes) 330 340 200’ 200’ - 200’

NB Lt 120 110 175’ 532’ 200’ 200’^

US250 & EB SR2

Ramp

90 sec

Cycle

110 sec

Cycle

EB Lt. (2 lanes) 170 310 375’ 350’ 900’/430’ 900’/430’

EB Rt. 160 280 350’ - 815’ 815’

US250 &

Applebee’s/Park Pl.

90 sec

cycle

110 sec

cycle

NB Rt. 30 110 100’ 625’ 180’ 180’**

# Does not include 50’ taper

^ Existing piers limit distance

**Obtaining the required length is beyond the scope of the project.

The proposed Build for the WB ramp exits SR2 mainline as a single lane & then widens out on both

sides simultaneously to form 3 lanes at the intersection with US250. The 3 lanes consist of a (Lt. –

Thru & Rt. – Rt.).



No-Build WB SR2 & US250 Exit Ramp

Build WB SR2 & US250 Exit Ramp



APPEND ALL ANALYSES FILES

Conclusion:

The IMS verifies that the level of service is not degraded between the design year no-build

condition and the design year build condition. The study meets the requirements of the

Ohio Department of Transportation.


office of roadway engineering - ohio department of ......interchange operations study (ios) reports...

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