traffic signals 101
DESCRIPTION
Traffic Signals 101. Topic 1 Why?. Why?. Who initiates a signal? Developer City/County Politician Public State. Why?. Signal Warrants Traffic control signals should not be installed unless one or more of the signal warrants in the MN MUTCD are met - PowerPoint PPT PresentationTRANSCRIPT
2015 Traffic Signals 101
Topic 1Why?
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• Who initiates a signal?• Developer• City/County• Politician• Public• State
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• Signal Warrants• Traffic control signals should not be installed
unless one or more of the signal warrants in the MN MUTCD are met
• The satisfaction of a warrant or warrants is not in itself justification for a signal
• Information should be obtained by means of engineering studies and compared with the requirements set forth in the warrants
• An Intersection Control Evaluation report needs to be prepared (see slide 8)
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• Warrant 1 - Eight-Hour Vehicular Volume• Warrant 2 - Four-Hour Vehicular Volume• Warrant 3 - Peak Hour• Warrant 4 - Pedestrian Volume
Signal Warrants
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• Warrant 5 - School Crossing • Warrant 6 - Coordinated Signal System• Warrant 7 - Crash Experience• Warrant 8 - Roadway Network• Warrant 9 - Intersection Near a Grade
Crossing
Signal Warrants
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• Warrant 1 Example• The Minimum Vehicular Volume, Condition A, is
intended for application at locations where a large volume of intersecting traffic is the principal reason to consider installing a traffic control signal
• The Interruption of Continuous Traffic, Condition B, is intended for application at locations where condition A is not satisfied and where the traffic volume on a major street is so heavy that traffic on a minor intersecting street suffers excessive delay or conflict in entering or crossing the major street
Warrant 1 tables
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TimeTotal of Both Major Street. Approaches
Higher Minor Street Approach
Total of Both Major Street. Approaches
Higher Minor Street Approach
Hour Satisfied?
6:00 to 7:00 650 205 600 200 Yes7:00 to 8:00 690 250 600 200 Yes8:00 to 9:00 640 201 600 200 Yes9:00 to 10:00 600 190 600 200 No10:00 to 11:00 550 100 600 200 No11:00 to 12:00 560 120 600 200 No12:00 to 1:00 600 160 600 200 No1:00 to 2:00 590 130 600 200 No2:00 to 3:00 580 180 600 200 No3:00 to 4:00 600 190 600 200 No4:00 to 5:00 630 220 600 200 Yes5:00 to 6:00 700 250 600 200 Yes6:00 to 7:00 680 230 600 200 Yes7:00 to 8:00 550 200 600 200 No8:00 to 9:00 450 190 600 200 No9:00 to 10:00 400 100 600 200 No
Warrant not met for Condition A (6 of 8 hours met)
Vehicles Per Hour Minimum Required
600 200
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• Intersection Control Evaluation (ICE)• In the past, the only perceived solution to
traffic delay and safety problems for at-grade intersections was the installation of a traffic signal
• Based on Signal Justification Reports (SJR)• Other options including stop control,
roundabouts, and unconventional reduced-access intersections, may be acceptable alternatives
ICE Book
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• ICE Definition• Intersection Control Evaluation, or ICE, is
a process that identifies the best intersection control through a comprehensive analysis and documentation of the technical (safety and operational), economic, and political issues of viable alternatives
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• Purpose of ICE• Evaluate various intersection designs• Select the optimal control for an
intersection based on an objective analysis for the existing conditions and future needs
• Document all technical, financial, and political issues in the ICE Report
• Replaces the SJR
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• Cover ManualsSignal & Lighting
Certification
Roadway LightingDesign Manual
Minnesota Manualon Uniform Traffic
Control Devices(MN MUTCD)
Signal Design Manual(Update in 2014)
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• Cover Manuals
StandardSpecifications
Traffic EngineeringManual (TEM)
Signal Optimizationand Timing Manual
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• For up-to-date information, visit:• http://www.dot.state.mn.us/trafficeng/