Pedestrian and bicycle accommodations on superstreets.

PDFTech ReportFHWA/NC/2012-13Signalized intersectionsCrosswalksPedestrian safetyBicycle safetyMicrosimulationU turnsTravel timeStopped time delayTraffic signal cycleNorth CarolinaNorth Carolina. Dept. of Transportation. Research and Analysis GroupHummer, Joseph E.Holzem, Anne M.Rouphail, Nagui M.Cunningham, Christopher M.O\ue2\u20ac\u2122Brien, Sarah W.Schroeder, Bastian J.Salamati, KatyFoyle, Robert S.Wayne State University. Dept. of Civil and Environmental EngineeringNorth Carolina State University. Dept. of Civil, Construction, and Environmental EngineeringUnited States. Federal Highway AdministrationUS Transportation CollectionThe objective of this research was to consider the unique challenges for pedestrians and bicyclists at superstreet intersections andrecommend crossing alternatives for both users. For pedestrians the options included the diagonal cross, median cross, two-stageBarnes Dance cross and midblock cross. For bicyclists the options included the bicycle U-turn, bicycles using the vehicle U-turn,the bicycle direct cross and the midblock cross. These options were analyzed through microsimulation based on average stoppeddelay per route, average number of stops per route, and average travel time per route. Furthermore, various parameters wereanalyzed per each of the crossing geometries including two signal cycle lengths, two signal splits, two signal offset designs, andtwo midblock distances. The results for pedestrians showed that the two-stage Barnes Dance crossing produced the lowest valuesfor average stopped delay, average number of stops, and average travel time. However, since the Barnes Dance is designed foran intersection with high volumes of pedestrians, the pedestrian option recommended for most superstreets was instead acombination of the diagonal cross with the midblock cross. The levels that ultimately influenced travel time for pedestrians werea cycle length of 90 seconds rather than 180 seconds, a signal split of 60/40 rather than 75/25, and an offset signal design wherethe vehicle platoons arrived at different times rather than simultaneously. The results for bicyclists showed that the bicycle directcross had the lowest average number of stops and the lowest average travel time. The bicycle option with the lowest stoppeddelay was the vehicle U-turn. The levels that produced lower travel time values for bicyclists included a cycle length of 90seconds, a signal split of 75/25, and situations where the vehicle platoons arrived at different times rather than simultaneously.The recommended bicycle options for the superstreet were the bicycle direct cross and the midblock cross implemented together.Additionally, the research outcomes include suggestions for public outreach materials in the form of a brochure and discussionswith public groups