Agenda - Council - 07/27/1999 - Laserfiche WebLink

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July 1, 1994 TRAFI~IC ENGINEERING MANUAL 9-5.00 (Continued) Warrant 7: Current Mn/DOT interpretation of Warrant 7 is that its intent is the use of a signal to pull traffic away from other intersections, "to encourage concentration and organization of traffic flow networks." Therefore, policy is that Warrant 7 does not apply to isolated intersections, but rather to intersections in urban grid systems. Warrant 8: Warrant 8 allows the combination of any two of Warrants 1, 2, and 3. Therefore, if a report addresses the combination of Warrant I and Warrant 2, the mainline criterion of Warrant 2 with the cross- street combination of Warrant 1 is the proper combination. Note the MN MUTCD requires "adequate trial of less restrictive remedies" before signalization under Warrant 8. Signalized intersections that do not meet 80 percent of the volume requirements of MN MUTCD Warrant 1 or 2, but meet 60 percent of the volume requirements of Warrant I are in the gray area and should be considered for signal removal. Additional studies, findings, engineering judgement and documentation beyond the volume requirements will be needed to justify retaining the signal. Signalized intersections that do no meet 60 percent of the volume requirements of MN MUTCD Warrants 1 and meet no other Warrant should be considered unjustified traffic control signals and should be removed. The traffic signal removal decision process shall be followed as set forth in the "User Guide for Removal of Not Needed Traffic Signals,FHWA- IP-80-12, November 1980. O Warrants 9-11: These warrants may' not be addressed by projected or hypothetical volumes, or In the traffic signal removal process, the traffic for as-yet-unbuilt intersections. Actual on-site engineer considers all the findings and the studies are required, decision is made whether or not to remove the " traffic signal. The final decision concerning There is not enough evidence at hand to determine signal removal is a blend of analytical a mean value or 85th percentile values for peak procedures and political considerations coupled hour and fourth-highest hour, particularly for sites with professional judgement. However, the with sharp-peaking distributions. ' technical findings from the analysis should ,~ provide a strong factual basis for reaching, 1) Justification for revision of existing Traffic supporting and defending the final decision or Control Signals recommendation. A Signal justification report shall be prepared for Ail findings of the decision process .shall be existing signals that are: summarized by the traffic engineer in a signal · Completely rebuilt Revised: updating to meet current standard; phase chang.es or coordination changes requiring rewiring, pole or mast arm changes and controller change out; adding or removing an approach or turn lane to an intersection A Signal Justification Reports are not required for: Minor work caused by road construction: pole or cabinet relocation Adding new loops for detection Revising a signal head · Changing out controller cabinet only for maintenance reasons · Adding Emergency Vehicle Preemption 'and it is obvious to the traffic engineer that the signal meets one of the MN MUTCD warrants. Signal Removal Justification Reports shall be prepared for all existing signals that are determined to be removed. 2) Justification Criteria: Signalized intersections that meet 80 percent of the volume requirements of MN MUTCD Warrant 1 or 2 should be considered justified. justification report or a signal removal justification report, if so determined. All traffic signals that are determined to be retained shall be revised to meet current standards. These traffic signals should be prioritized along with other traffic signal projects and scheduled for revision as permitted. Flashing beacons include beacons mounted on span wire directly over an intersection, and beacons mounted on pedestal above stop signs (red) and intersections ahead symbols signs (yellow). Both overhead pedestal mounted beacons have advantages and disadvantages. Overhead beacons maybe confused with all way flashing red signals indicating or may distract the motodst from roadway signing, but they aid the motorist in locating the intersection. Pedestal mounted beacons help draw attention to stop and intersection ahead signing, but do not heip locate the intersection for the mainline driver who sees only flashing yellow mounted on an intersection ahead sign, somewhere in advance of the intersection itself. Sight distance or geometry may also tend to favor one system over another. In any case, any flashing beacon must be justified under one or more of the following warrants. .9_14 O~4~