1. The I-465 West Leg Reconstruction Project
A presentation of:
Flexible Design
3 Case Studies
March 9, 2011

2. What and Where?
Accelerate 465 is an INDOT project, that will reconstruct 11 miles of I-465 from just south of 56th Street to just south of the I-70 interchange.
This reconstruction will :
Upgrade interchange ramp and mainline capacities.
Replace deteriorating bridges.
Replace deteriorating pavement.
Upgrade geometric conditions to current standards
i.e.: eliminate tight weaving movements, improve sight distances, etc.

3. Why Accelerate 465?
This segment of I-465 was one of the first interstates built in Marion County.
Growth in population, special events, and businesses require expanded transportation resources.
The current design was not sufficient to meet the current use and projected needs.
The lack of north/south routes requires residents to use this segment of I-465 for local trips.
Increased business traffic, interstate traffic, expanded airport traffic and increased special event traffic, all contribute to congestion problems.

4. Project Scope Accelerate 465 reconstruction includes
11 miles of interstate, 4 lanes each way
8 interchanges
46 bridges

5. Right of Way – Urban Corridor
Accelerate 465 Right of Way Requirements
50 Residential Relocations
10 Business Relocations
1 Apartment Relocations
1 Hotel Acquisition
120 acres of Right of Way

6. Case Study No. 1: Promenade Concept
Design Topic
Promenade concept
Safely moving pedestrians through busy interchanges with free-flow ramps
38th Street case study

7. Case Study No. 1: Promenade Concept
Promenade Goals
Pedestrian safety
Community connectivity
Promenade Locations
38th Street, 10th Street, Rockville Road, Washington Street

8. Case Study No. 1: Promenade Concept
Overview – 38th Street

9. Case Study No. 1: Promenade Concept
Concept Images

10. Case Study No. 1: Promenade Concept
Concept Images

11. Case Study No. 1: Promenade Concept
Concept Section

12. Case Study No. 1: Promenade Concept
Design Features
Applicable at partial cloverleaf interchanges
28 ft width provides room for community planters and lighting
Pedestrian Safety
Pedestrians do not cross free-flow directional ramps and loop ramps
Pedestrians cross ramps at stop conditions only
Signalized crosswalks
Barrier protection

13. Case Study No. 1: Promenade Concept
Pedestrian Routing – 38th Street

14. Case Study No. 1: Promenade Concept
Intersection Detail – 38th Street

15. Case Study No. 1: Promenade Concept
Photo - 38th Street

16. Case Study No. 1: Promenade Concept
Photo - 38th Street

17. Case Study No. 1: Promenade Concept
Photo - 38th Street

18. Case Study No. 1: Promenade Concept
Photo - 38th Street

19. Case Study No. 2: Sam Jones Expressway
Design Topic
Interchange type determination
Sam Jones Expressway Interchange Concept Revised…
From semi-directional interchange
To diamond interchange
Impacts
Traffic impacts & cost benefits

20. Case Study No. 2: Sam Jones Expressway
I-465
I-70
The Big Picture

21. Semi-Directional Interchange Layout
Case Study No. 2: Sam Jones Expressway
Semi-Directional Interchange Layout

22. Case Study No. 2: Sam Jones Expressway
Benefits of Semi-directional Interchange
Traffic keeps moving
Limitations of Semi-directional Interchange
Right-of-way & environmental challenges
Substandard geometrics
Changing airport traffic pattern
Heaviest movements are redundant
Three bridges to maintain
Higher cost

23. Diamond Interchange Layout
Case Study No. 2: Sam Jones Expressway
Diamond Interchange Layout

24. Case Study No. 2: Sam Jones Expressway
Benefits of Diamond Interchange
Smaller footprint
Desirable geometrics
Considers airport relocation
Only one bridge to maintain
Lower cost
Limitations of Diamond Interchange
Traffic signals
Future expansion options

25. Case Study No. 2: Sam Jones Expressway
Traffic Analysis
Impact to commuters
Triple-left turn for SB to EB [a.m. peak movement]
Operates at LOS “C” in design year
Turning roadway for WB to NB [p.m. peak movement]
Less desirable alternate route for EB I-70 commuters

26. Case Study No. 2: Sam Jones Expressway
Impacts to I-70 interchange
Concerns about diverted drivers
SB to EB loop design year traffic 480 vph in peak hour
Loop has capacity to handle additional 1420 vph
That is 70% of peak hour traffic from Sam Jones SB to EB movement

27. Case Study No. 2: Sam Jones Expressway
Cost Savings
18% reduction in pavement area
43% reduction in bridge area
22% reduction in retaining walls
Net savings $6 million

28. Case Study No. 2: Sam Jones Expressway
Construction is well under way!

29. Case Study No. 3: I-74 Interchange
Design Topic
Bridge shoulder orientation
I-74 Single-Lane left turning directional ramp EB I-74 to NB I-465
“Flipping the shoulders”
Two Design Exceptions – Shoulder Width and Stopping Sight Distance
Impacts
Driver expectancy & Cost benefits

30. Original Interchange Layout
Case Study No. 2: I-74 Interchange
Original Interchange Layout

31. Final Interchange Layout
Case Study No. 2: I-74 Interchange
Final Interchange Layout

32. Modified Bridge Location
Case Study No. 3: I-74 Interchange
Modified Bridge Location

33. Case Study No. 3: I-74 Interchange
Proposed Design Features
16 ft Ramp Driving Lane
10 ft Left Shoulder [incl. barrier offset]
6 ft Right Shoulder [incl. barrier offset]
32 ft Clear Roadway Width
Design Exceptions Required
Shoulder Width [Right Shoulder]
HSSD [Left Shoulder]

34. Bridge Typical Section – Ramp “REN”
Case Study No. 3: I-74 Interchange
Bridge Typical Section – Ramp “REN”

35. Case Study No. 3: I-74 Interchange
Ramp Design Data
AADT 2006 – 4,385 vpd, 4% trucks
AADT 2026 – 6,785 vpd, 4% trucks
Design Speed – 45 mph
HSSD Required – 360 ft
Right Shoulder Width
10 ft Standard width is 8 ft + 2 ft barrier offset
Provides ‘break down’ area
Driver expectation

36. Case Study No. 3: I-74 Interchange
HSSD Analysis for Left Shoulder/Barrier [With 6 ft Right Shoulder]
Design Speed
45 mph
40 mph
35 mph
Shoulder Width
21.3 ft
13.6 ft
7.2 ft
Added Cost
$1,890,000
$604,800 $0
HSSD Analysis for Left Shoulder/Barrier [With10 ft Right Shoulder]
Design Speed
45 mph
40 mph
35 mph
Shoulder Width
21.3 ft
13.6 ft
7.2 ft
Added Cost
$2,562,000
$1,276,800
$201,600

37. Case Study No. 3: I-74 Interchange
HSSD Summary
With 10 ft left shoulder…
HSSD provided is 290 ft.
Equates to operating speed 38 mph
Remedial Actions
Cautionary signage – 35 mph

38. Case Study No. 3: I-74 Interchange
How important is added right shoulder width in this example? Consider the following…
“Break-down” area is provided on left
32 ft clear roadway width maintained
Short overall length of condition – 850 ft
Interchange will be lighted
Driver awareness is increased in an urban interchange
Lowest cost option

39. Case Study No. 3: I-74 Interchange
Other DOT’s Using This Concept
WisDOT – Marquette Interchange
WisDOT – Big Zoo Interchange
ODOT – 71/670 Interchange
Design exception was approved
I-74 interchange construction is well underway!

40. Case Study No. 3: I-74 Interchange
Another example, from Australia…

41. Thank You On behalf of INDOT and the Accelerate I-465 Project Team,
for the opportunity to present this information.
Questions?