intersection control evaluation (ice). outline background ice process impacts current status

Intersection Control Intersection Control Evaluation (ICE)Evaluation (ICE)

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


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


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


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


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


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


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


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


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


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)


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


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


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


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


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


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)


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)

QUESTIONS?QUESTIONS?

intersection control evaluation (ice). outline background ice process impacts current status

Documents

yearthe ice processphase

projectthe ice processphase

softwarethe ice processphase

viable alternative

acceptable level of

appropriate level of

crash history

approvalall decisions