Common use of Traffic Queue Length Clause in Contracts

Traffic Queue Length. ‌ We manually counted the traffic queue length in vehicles from field recorded video data. Table 8-8 shows the traffic queue lengths on cross-streets. Because of time constraints, we analyzed and summarized data only from Mondays. Table 8-8 Traffic Queue Length on Cross Streets in Phase One Test Intersection Cross-Street Average Queue Length Per Cycle Standard Deviation Maximum Median TSP Off Alderwood Mall Parkway South approach 2.65471 2.41476 14 2 36th Ave West approach 3.20079 2.58121 16 3 TSP On Alderwood Mall Parkway South approach 2.64318 2.43128 12 2 Alderwood Mall Parkway North approach 1.63679 1.40252 7 1 36th Ave West approach 3.27135 2.76868 16 3 We also used a paired t-test to compare the average queue length before and after TSP implementation. The t ratio was -1.578, the absolute value of which was smaller than the critical t ratio of 2.920 at p=0.05. Therefore, the change of the average queue length on cross-streets after the SS-RTSP implementation was not significant. The average traffic queue length slightly increased for about 0.07 vehicles per signal cycle when the TSP system was turned on. However, on the southbound corridor of the Alderwood Mall Parkway intersection, traffic queue length decreased for about 0.01 vehicles per cycle. This result may be due to regular traffic variations between the two study days. Standard deviations of queue length also increased a little for all three cross- streets when TSP was on. The maximum queue length stayed at almost the same level after the TSP implementation. On the southbound corridor of the Alderwood Mall Parkway intersection, the maximum queue length even decreased for two vehicles per cycle when the TSP system was on. The median value of traffic queue length remained constant before and after the implementation of the TSP system.