Agenda - Public Works Committee - 04/18/2017

Home

MnIDO7Tizffic Signal Timing and Coordination Manual, Use of posted speed limit is recomnnended. Non - arterial approaches may have lower speeds than the po�edspeed Um�beoausethey are often inastop condition upon the arrival oftraffic. Grades affect the acceleration rate of -the left turner and the stopping distance and speed of the opposing through traffic and are therefore considered inconjunction with speeds, Cross Product: The left turn volume multiplied.by the opposing through volume. The cross product neloeu used are taken from the Wisconsin Department of Transportation (VVimDOT) Traffic Signal Design KHanoo| discussion on left turn conflicts analysis, Chapter 2, Section 3, Subject 4. Cross product used represents a high frequency ofconflicts for left turners looking for gaps in through FYA during Free Operation With the variable -phasing operation of the FYA head, free operation will no longer have an assigned fixed phasing operation. fherefnne,standard free operation will need tn baset up|nthe signal controller so technicians can put signals quickly to FR�E with a standard phasing operation desired at the specific timie. Here is an example of the standard FREE operations that will need to be set up in the signal controller, l. All left turns protected 2, Ail left turns protected/permiysive 3. All left turns permissive 4` Mainline protected, cross street protected permissive 5. Mainline protected, cross street permissive 5. Mainline protected/ponn/soive,cross street protected 7. MuinUneprotaoted/ponnisdme, cross street permissive 8. Mainline permissive, cross street protected — 8. Mainline permissive, crosostTeetprotected/oermisxive Minimum Green Times Minimum Green Times Mn/DOT currently sets the minimum green time based on the type of phasing operation where protected lefts have e7second minimum green and proteo1od/permbsk/e|efty have o G second minimum green. Given the FYA head is a variable phasing operation haoc[ a decision will need to be mode as to if there should be more than one minimum green value that changes with the phasing operation; or if.9 universal minimum green should apply tooUphasing operations. if one minimum green is used, and if a leftturn phase will ever run protected, the left turn minimum green should be set at seconds. If left turn will never run protected (i.e. only run prote ctad/permisn>ve or then permissive), e . EVPPreemption Operation under FYA A. Protected -only Operation When the FYAisnot allowed (protected on|W,thepre-emptiunxxi|(br7ngupthepruteoted/eft1u[n and the adjacent through phase, The opposing PY&will not baallowed during preemption (refer to Exhibit 3-15). Page | 3-31