Intersection Control Evaluation (ICE)

1. Intersection Control Evaluation (ICE)

2. Outline • Background • ICE Process • Impacts • Current Status

3. Background • Signal Justification Reports • Completed during final design • Document warrants • Straightforward, but no consideration of other alternatives

4. Background • Increased Traffic Control Options • All-way stop • Signal • Roundabout • Access Management • Grade Separation • Non-Traditional • Continuous flow • Michigan left

5. Background • Need process to analyze intersection traffic control options • Document analysis and selection of preferred alternative

6. Why Change? • All intersection control decisions documented • Early decisions help limit scope creep • Improve coordination and collaboration with local agencies • All intersection control options considered on an equal basis

7. The ICE Process • Required on all trunk highways • State-Aid is considering adoption • Not required for two-way stop or uncontrolled intersections • Written by licensed engineer • Approved by the District Traffic Engineer

8. The ICE Process • Goal: • Consider technical, financial, and political aspects of each control alternative • Select optimal intersection control

9. The ICE Process • Phase 1- Scoping • Complete as early in the project development process as possible • Can occur prior to project programming • Determine feasibility of traffic control options • Phase 2- Alternative Selection • Layout development • Identify recommended traffic control

10. The ICE Process

11. The ICE Process • Phase 1- Scoping • Conduct a technical analysis of options • Initial public acceptability of options • Interim report and recommendations

12. The ICE Process • Phase 1- Scoping • Warrant analysis • Traffic volumes (vehicle/pedestrian/bicycle), crash history, delay • All-way stop • Signal • Roundabout considered warranted if meets either AWS or signal warrants

13. The ICE Process • Phase 1- Scoping • Justification • Safety • Congestion • Intersection spacing • Future traffic volumes • Percentage of turning traffic • Vehicle types and percentages • Sight distance • Right of Way • Available funds • Local support

14. The ICE Process • Phase 1- Scoping • Crash Evaluation • Crash diagram with most recent 3 years of data for existing intersections • Estimate anticipated crashes for each traffic control alternative • Calculate crash reductions per year • Calculate crash cost reduction per year

15. The ICE Process • Phase 1- Scoping • Capacity Evaluation • Existing AM and PM peak hour volumes • Design year AM and PM peak hour volumes • Existing and design year pedestrian and bicycle volumes • Design vehicle • Horizontal, vertical, and site constraints • District Traffic Engineer to determine acceptable level of analysis (including software)

16. The ICE Process • Phase 1- Scoping • If only one viable alternative comes out of Phase 1, ICE is complete • For corridor or planning study, Phase 1 evaluation may be sufficient • District Traffic Engineer to determine appropriate level of analysis for each project

17. The ICE Process • Phase 1- Scoping • Preservation projects and signal revisions still require memo/letter to be submitted for approval • All decisions and evaluation should be documented in final ICE report

18. The ICE Process • Phase 2- Alternative Selection • Develop conceptual layouts • Determine ROW impacts and estimated costs • Estimate construction costs • Assess public involvement and acceptance • Prepare final ICE document

19. The ICE Process • Phase 2- Alternative Selection • Other considerations • Skew angle • Offset approaches • Odd number of approaches • Closely spaced intersections • Approach grades

20. The ICE Process • Phase 2- Alternative Selection • More detailed capacity analysis • AWS- Synchro/SimTraffic • Signals- Synchro/SimTraffic • Roundabouts- RODEL • Roundabouts in series or roundabouts within traffic control system- VISSIM

21. The ICE Process • Phase 2- Alternative Selection • RODEL is a roundabout design tool (empirically based) • Synchro/SimTraffic and VISSIM are analysis tools (gap acceptance based)

22. The ICE Process • Phase 2- Alternative Selection • Other considerations • Coordinated signal systems • Interregional Corridors (IRC) • Compare to recommendations of corridor study • Address impacts on IRC performance

23. Mn/DOT Impacts • Dependent upon two major factors • Project origin • Size and/or type of project • For internal project, Mn/DOT completes analysis and ICE report • For external project, outside agency or consultant completes ICE • District makes decision on the scope/detail of the analysis

24. Mn/DOT Impacts • Internal Project Roles • Capacity and safety analysis (Traffic) • Public involvement (District) • Conceptual layouts and impacts (Design) • Final report documentation (Traffic)

25. Other Impacts • Program and Project Management System (PPMS) modification • New software and training • Increased internal and external coordination • Districts document their process (warrants and justification)

26. Current Status • Technical Memo No. 07-02-T-01 (03/20/07) • Actions in Metro • Purchase of Rodel and VISSIM • Drafting a detail of “how to” complete and ICE study • Simplifying the capacity analysis

27. Current Status • Actions in Metro • Reviewing ICE documents • Timing of implementation (FY 2008)

28. QUESTIONS?