intersection control evaluation (ice). outline background ice process impacts current status
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OutlineOutline
BackgroundBackground ICE ProcessICE Process ImpactsImpacts Current StatusCurrent Status
BackgroundBackground
Signal Justification ReportsSignal Justification Reports– Completed during final designCompleted during final design– Document warrantsDocument warrants– Straightforward, but no consideration of Straightforward, but no consideration of
other alternativesother alternatives
BackgroundBackground
Increased Traffic Control OptionsIncreased Traffic Control Options– All-way stopAll-way stop– SignalSignal– RoundaboutRoundabout– Access ManagementAccess Management– Grade SeparationGrade Separation– Non-TraditionalNon-Traditional
Continuous flowContinuous flow Michigan leftMichigan left
BackgroundBackground
Need process to analyze intersection Need process to analyze intersection traffic control optionstraffic control options
Document analysis and selection of Document analysis and selection of preferred alternativepreferred alternative
Why Change?Why Change?
All intersection control decisions All intersection control decisions documenteddocumented
Early decisions help limit scope creepEarly decisions help limit scope creep Improve coordination and Improve coordination and
collaboration with local agenciescollaboration with local agencies All intersection control options All intersection control options
considered on an equal basisconsidered on an equal basis
The ICE ProcessThe ICE Process
Required on all trunk highwaysRequired on all trunk highways State-Aid is considering adoptionState-Aid is considering adoption Not required for two-way stop or Not required for two-way stop or
uncontrolled intersectionsuncontrolled intersections Written by licensed engineerWritten by licensed engineer Approved by the District Traffic Approved by the District Traffic
EngineerEngineer
The ICE ProcessThe ICE Process
Goal:Goal:– Consider technical, financial, and Consider technical, financial, and
political aspects of each control political aspects of each control alternativealternative
– Select optimal intersection controlSelect optimal intersection control
The ICE ProcessThe ICE Process
Phase 1- ScopingPhase 1- Scoping– Complete as early in the project Complete as early in the project
development process as possibledevelopment process as possible– Can occur prior to project programmingCan occur prior to project programming– Determine feasibility of traffic control Determine feasibility of traffic control
optionsoptions Phase 2- Alternative SelectionPhase 2- Alternative Selection
– Layout developmentLayout development– Identify recommended traffic controlIdentify recommended traffic control
The ICE ProcessThe ICE Process
Phase 1- ScopingPhase 1- Scoping– Conduct a technical analysis of optionsConduct a technical analysis of options– Initial public acceptability of optionsInitial public acceptability of options– Interim report and recommendationsInterim report and recommendations
The ICE ProcessThe ICE Process
Phase 1- ScopingPhase 1- Scoping– Warrant analysisWarrant analysis
Traffic volumes Traffic volumes (vehicle/pedestrian/bicycle), crash (vehicle/pedestrian/bicycle), crash history, delayhistory, delay– All-way stopAll-way stop– SignalSignal– Roundabout considered warranted if meets Roundabout considered warranted if meets
either AWS or signal warrantseither AWS or signal warrants
The ICE ProcessThe ICE Process
Phase 1- ScopingPhase 1- Scoping– JustificationJustification
SafetySafety CongestionCongestion Intersection spacingIntersection spacing Future traffic volumesFuture traffic volumes Percentage of turning trafficPercentage of turning traffic Vehicle types and percentagesVehicle types and percentages Sight distanceSight distance Right of WayRight of Way Available fundsAvailable funds Local supportLocal support
The ICE ProcessThe ICE Process
Phase 1- ScopingPhase 1- Scoping– Crash EvaluationCrash Evaluation
Crash diagram with most recent 3 years of Crash diagram with most recent 3 years of data for existing intersectionsdata for existing intersections
Estimate anticipated crashes for each traffic Estimate anticipated crashes for each traffic control alternativecontrol alternative
Calculate crash reductions per yearCalculate crash reductions per year Calculate crash cost reduction per yearCalculate crash cost reduction per year
The ICE ProcessThe ICE Process
Phase 1- ScopingPhase 1- Scoping– Capacity EvaluationCapacity Evaluation
Existing AM and PM peak hour volumesExisting AM and PM peak hour volumes Design year AM and PM peak hour volumesDesign year AM and PM peak hour volumes Existing and design year pedestrian and Existing and design year pedestrian and
bicycle volumesbicycle volumes Design vehicleDesign vehicle Horizontal, vertical, and site constraintsHorizontal, vertical, and site constraints
– District Traffic Engineer to determine District Traffic Engineer to determine acceptable level of analysis (including acceptable level of analysis (including software)software)
The ICE ProcessThe ICE Process
Phase 1- ScopingPhase 1- Scoping– If only one viable alternative comes out If only one viable alternative comes out
of Phase 1, ICE is completeof Phase 1, ICE is complete– For corridor or planning study, Phase 1 For corridor or planning study, Phase 1
evaluation may be sufficientevaluation may be sufficient– District Traffic Engineer to determine District Traffic Engineer to determine
appropriate level of analysis for each appropriate level of analysis for each projectproject
The ICE ProcessThe ICE Process
Phase 1- ScopingPhase 1- Scoping– Preservation projects and signal Preservation projects and signal
revisions still require memo/letter to be revisions still require memo/letter to be submitted for approvalsubmitted for approval
– All decisions and evaluation should be All decisions and evaluation should be documented in final ICE reportdocumented in final ICE report
The ICE ProcessThe ICE Process
Phase 2- Alternative SelectionPhase 2- Alternative Selection– Develop conceptual layouts Develop conceptual layouts – Determine ROW impacts and estimated Determine ROW impacts and estimated
costscosts– Estimate construction costsEstimate construction costs– Assess public involvement and Assess public involvement and
acceptanceacceptance– Prepare final ICE document Prepare final ICE document
The ICE ProcessThe ICE Process
Phase 2- Alternative SelectionPhase 2- Alternative Selection– Other considerations Other considerations
Skew angleSkew angleOffset approachesOffset approachesOdd number of approachesOdd number of approachesClosely spaced intersectionsClosely spaced intersectionsApproach gradesApproach grades
The ICE ProcessThe ICE Process
Phase 2- Alternative SelectionPhase 2- Alternative Selection– More detailed capacity analysis More detailed capacity analysis
AWS- Synchro/SimTrafficAWS- Synchro/SimTrafficSignals- Synchro/SimTrafficSignals- Synchro/SimTrafficRoundabouts- RODELRoundabouts- RODELRoundabouts in series or roundabouts within Roundabouts in series or roundabouts within
traffic control system- VISSIMtraffic control system- VISSIM
The ICE ProcessThe ICE Process
Phase 2- Alternative SelectionPhase 2- Alternative Selection– RODEL is a roundabout design tool RODEL is a roundabout design tool
(empirically based)(empirically based)– Synchro/SimTraffic and VISSIM are Synchro/SimTraffic and VISSIM are
analysis tools (gap acceptance based)analysis tools (gap acceptance based)
The ICE ProcessThe ICE Process
Phase 2- Alternative SelectionPhase 2- Alternative Selection– Other considerationsOther considerations
Coordinated signal systemsCoordinated signal systemsInterregional Corridors (IRC)Interregional Corridors (IRC)
– Compare to recommendations of corridor Compare to recommendations of corridor studystudy
– Address impacts on IRC performanceAddress impacts on IRC performance
Mn/DOT Impacts Mn/DOT Impacts
Dependent upon two major factorsDependent upon two major factors– Project originProject origin– Size and/or type of projectSize and/or type of project
For internal project, Mn/DOT For internal project, Mn/DOT completes analysis and ICE reportcompletes analysis and ICE report
For external project, outside agency For external project, outside agency or consultant completes ICEor consultant completes ICE
District makes decision on the District makes decision on the scope/detail of the analysisscope/detail of the analysis
Mn/DOT Impacts Mn/DOT Impacts
Internal Project Roles Internal Project Roles – Capacity and safety analysis (Traffic)Capacity and safety analysis (Traffic)– Public involvement (District)Public involvement (District)– Conceptual layouts and impacts Conceptual layouts and impacts
(Design)(Design)– Final report documentation (Traffic)Final report documentation (Traffic)
Other ImpactsOther Impacts
Program and Project Management Program and Project Management System (PPMS) modificationSystem (PPMS) modification
New software and trainingNew software and training Increased internal and external Increased internal and external
coordinationcoordination Districts document their process Districts document their process
(warrants and justification)(warrants and justification)
Current StatusCurrent Status
Technical Memo No. 07-02-T-01 Technical Memo No. 07-02-T-01 (03/20/07)(03/20/07)
Actions in MetroActions in Metro– Purchase of Rodel and VISSIMPurchase of Rodel and VISSIM– Drafting a detail of “how to” complete Drafting a detail of “how to” complete
and ICE study and ICE study – Simplifying the capacity analysis Simplifying the capacity analysis
Current StatusCurrent Status
Actions in MetroActions in Metro– Reviewing ICE documentsReviewing ICE documents– Timing of implementation (FY 2008)Timing of implementation (FY 2008)