Independent ReviewPoplar St. Bridge

Mission Statement• Provide an independent review of Poplar Street Bridge (PSB)/I-55/I-70 Interchange Project

• Review design options under consideration by MoDOT and IDOT

• Assess possibilities for other design alternatives not considered by the state DOTs

• Develop recommendations on a preferred design alternative and prepare a report that examines the benefits, impacts, and costs of the various options

Directives & Constraints• Work within a totally independent environment, focused

on sound technical engineering principles and guidelines

• Safety is a priority

• Reduce or eliminate the primary causes of congestion, including weaving on the PSB

• Limited funding availability of $55M

• Rigorous examination of the feasibility of keeping the existing Memorial Drive ramp (SB to EB movement)

• Identify options to access IL Route 3 that maintain or improve the existing conditions

Major Tasks

Task Dates

Assemble & review all available data from DOTs and the EWG Council of Governments

7/16 – 8/3

Participate in a four‐day design charette to review existing options and develop additional alternatives

8/6 – 8/10

Prepare draft report of findings and recommendations

8/11 – 8/31

Prepare final report and draft presentation 9/1 – 9/21

Prepare for and deliver the final presentation to the EWG Board

9/26

Project Team

Project ManagerBarry Rolle, PE, VP

Geometrics

Dave Meier, PE, VP

Jay Chiglo, PE, VP

Pat Pechnick, PE, VP

Mike Ecker, PE

Dennis LaRose, PE, LEED AP*

Traffic/Planning

Ralph Batenhorst, PE, VP

Christopher Kinzel, PE

Bridge

Cory Imhoff, PE

* CDI Civil Design, Inc.

Initial Options Studied• Studied by MoDOT and IDOT• Contained in Draft AJR• Five of six at the interchange

Initial Options StudiedOption 1: Ramp B under I‐64 (right exit), inside merge 

Option 2: Ramp B under I‐64 (left exit), inside merge , I‐44 realign

Option 3: Ramp B under I‐64 (right exit), outside merge

Option 5: Ramp B under I‐64 (right exit), outside merge; Memorial realign

7th Street U‐Turn

Alt 2A: Ramp B under I‐64 (right exit), outside merge; I‐44 slight realign; Memorial realign

Conclusions on DOT Options• Geometrically, Option 3 could work

with tweaks but still had significant problems (Ramp merge with I-55, congestion, safety).

• Common theme with all was merge point constraints, safety, congestion. Excavation next to I-64 foundations is unacceptable.

• AJR came to the most logical and most technically sound conclusions given the constraints and original purpose for the project.

Enhancements & New Alternatives• Focused on Ramp B preservation• Three unique options (A, B, C) to preserve

Ramp B• None improved congestion over AJR

recommended alternative

2 lanes

2 lanes

2 lanes

addremove

Memorial Drive braid over SB 44 loop ramp

1 lane

2 lanes2 lanes

1 lane, right exit, from I-44

1 lane, left exit, from I-55

1 lane

2 lanes

2-lane left exit

2 lanes

1 lane

Option A Option B Option C

6 th

I-64 Corridor Lane Imbalance• Currently 3-2-4-4

• AJR 3-2-4-4

• Option A 3-2-5-4

PSB

A

B

3 2 4 4

PSB

64

6 th

3 2 4 4

PSB

A6 th

3 2 5 4

64

64

AB

Can we fix?

One Fix: MLK Connector• E.B. MLK to S.B. IL Route 3• 1 – 2 miles additional travel distance• Reduces travel time in P.M. peak

Existing Ramp B

Potential MLK/IL-3 Connector

55 3

3

N

~1.3mi

~0.9mi

~1.0mi

~1.0mi64

70

70

64

55

• Substructure Modifications• Slide EB Bridge South 9 ft

– Adds 5th EB Lane• Add Crossframes• Infill Orthotropic Decking• One 4-girder bridge• Redundancy, Stiffness,

Improved Performance• Cost-Effective

Two existing two-girder systems (looking east from west bank)

Another Fix: Widen Bridge (Slide)

PSB Slide PerformanceSubstructure & Foundations

• Current - Load In 6’ Caisson = 1691 kips• After Slide – Load In 6’ Caisson = 2022 kips• Approx. 20% Increase• Allowable = 1979 kips• 2% Overstress

What’s the Best Use of 5-Lane PSB?• Widen PSB 3-2-5-5: Does not eliminate No. 1

concern of commuters – I-64 congestion.

• 3-3-5-5 would address I-64 congestion. How to get there?

PSB

A3 2 5 5

64

?

6 th

6 th

What’s the Best Use of 5-Lane PSB?• Widen PSB 3-2-5-5: Does not eliminate No. 1

concern of commuters – I-64 congestion

• 3-3-5-5 would address I-64 congestion. How to get there?

PSB

A3 3 5 5

64

Third Lane on I‐64

I-64 Capacity Enhancement• Slide PSB• Modify Sixth Street ramps –create third lane on I-64• Eliminates I-64 congestion

Exit includes 3rd EB thru lane

3rd thru lane rejoins I-64

6th St on-ramp joins as 4th lane then tapers

2-lane ramp becomes 4th/5th EB lanes

2 lanes2 lanes

Approximate Sixth Street Ramp Departure Point

Potential 3rd Lane Rejoin Point

New Ramp for 3rd LaneN

64

To PSB

• Slide PSB• Modify Sixth Street ramps –create third lane on I-64• Eliminates I-64 congestion

I-64 Capacity EnhancementExit includes 3rd EB thru lane

3rd thru lane rejoins I-64

6th St on-ramp joins as 4th lane then tapers

2-lane ramp becomes 4th/5th EB lanes

2 lanes2 lanes

Cost Estimation: Evaluation• Evaluated estimates for original design options

• Recent bids lower than original estimate

• Miscellaneous items and contingencies further inflate prices

Cost Estimation: Components of OptionsOption

Estimated by

Subtotal(millions)

Grand Total *(millions)

Base – AJR Alt. 8MoDOTHDR

$32.6$22.3

$49.5$33.9

Option 3MoDOTHDR

$31.0$19.4

$47.1$29.5

Split 64 – InitialSplit 64 – Final 

HDRHDR

$5.1$20.7

$7.7$31.5

Option A (Loop Ramp) HDR $18.0 $27.3

PSB Slide HDR $14.1 $21.4

Option B (I‐44/I‐55 Split) HDR $36.7 $55.7

Option C (I‐55 Left Exit) HDR $34.3 $52.1

MLK/IL‐3 Connector HDR $10.8 $16.9

* Includes removals, mobilization, surveying, engineering, construction administration, and contingency

32% reduction

Cost Estimation: Options

Options ComponentsEstimated 

bySubtotal(millions)

Grand Total (millions)*

Option 3 Base + Option 3MoDOTHDR

$63.6$41.7

$96.6$63.4

Base, MLK Base + MLK Connector HDR $33.1 $50.8

Alt D, initialBase + MLK + PSB Slide + Split 64 ‐Initial

HDR $52.3 $79.9

Alt D, finalBase + MLK + PSB Slide + Split 64 – Initial + Split 64 ‐ Final

HDR $73.0 $111.4

Option AOption A+

Base + Option ABase + Option A + PSB Slide

HDRHDR

$40.4$54.4

$61.3$82.6

Option BOption B+

Base + Option BBase + Option B + PSB Slide

HDRHDR

$59.0$73.1

$89.7$111.0

Option COption C+

Base + Option CBase + Option C + PSB Slide

HDRHDR

$56.7$70.7

$86.1$107.4

* Includes removals, mobilization, surveying, engineering, construction administration, and contingency

Recommendations• Based on the findings of this analysis, the study

team recommends a program of phased improvements

• Initial project will alleviate an existing problem, but can also provide a long term, positive, regional benefit in terms of reduced congestion and increased accessibility

• Improves congestion and safety better than all study alternatives

Recommendations

PSB

MLK

MLK connector

Upgrade C & D, Remove B

1

1

$17.0M

$25.7M

CB

D

TOTALS1 $42.7M 2015

Recommendations

PSB

MLK

MLK connector

Upgrade C & D, Remove B

PSB Slide

I‐64 Split Initial

1

1

2

2

$17.0M

$25.7M

CB

Upgrade A

DA

2$7.7M

$8.3M$21.3M

TOTALS1 $42.7M2 $37.3M 2016

2015

Recommendations

PSB

MLK

MLK connector

Upgrade C & D, Remove B

PSB Slide

I‐64 Split Initial

I‐64SplitFinal

1

1

2

2

3

$17.0M

$25.7M

CB

Upgrade A

DA

2$7.7M

$8.3M$21.3M

$31.0M

TOTALS1 $42.7M2 $37.3M3 $31.0M

$111.0M

unfunded

2016

2015