Transit Travel Time Clause Samples
Transit Travel Time. Transit travel time data were calculated by using GPS position data. Table 8-3 shows the descriptive statistics for transit travel time over the test corridor. The east end of the corridor was defined as the point on the center line of the 164th Street SW at TSP reader 15034; and the west end was on the center line of 36th Avenue at the stop bar of the southbound approach. In comparison with the mean travel time of eligible trips with TSP off, the average travel time for the eastbound granted trips was 6.8 seconds shorter when TSP was on, which was 5.0 percent of the average eastbound travel time for eligible trips without TSP. The standard deviation of eastbound travel time was also lower for trips with granted signal priorities, which indicates that the travel time was more predictable when TSP was on. Table 8-3 Transit Corridor Travel Time in the Phase One Test Eligible Trips with TSP off Eligible Trips with TSP on TSP Granted Trips Mean Travel Time (sec) Westbound 142.9 144.4 146.7 Eastbound 135.2 131.6 128.4 Standard Deviation (sec) Westbound 29.2 30.3 28.9 Eastbound 32.6 32.8 30.4 Maximum (sec) Westbound 210.0 233.0 233.0 Eastbound 269.0 287.0 205.0 Minimum (sec) Westbound 95.0 87.0 90.0 Eastbound 85.0 79.0 82.0 For the westbound trips, the mean travel time was longer when the TSP was on, and even longer for the trips with granted priorities. This finding seemed to contradict our expectations. However, if we look at the locations of the westbound bus stops, the results are understandable. Of the three bus stops on the westbound corridor, two were near-side bus stops, which may have had negative impacts on trips with granted priority. Section
Transit Travel Time. Transit travel time data were calculated by using GPS position data. Table 9-3 shows the travel time statistics for the SR 99 corridor during the Phase Two test. The average transit travel time of eligible trips when TSP was on was 13 to 32 seconds shorter than that when TSP was off. With northbound and southbound together, the TSP saved an average of 26 seconds of transit travel time per trip, about 2.47 percent of the total corridor travel time. The mean transit travel time for the granted trips was even longer than that for all eligible trips with TSP off. This seems contradictory. However, given that only late trips would be granted TSP treatment, this result is not beyond our expectation. Another comparison between late trips with TSP on and off was conducted. The results showed that TSP saved 54 seconds of transit travel time (northbound and southbound together) for late trips, about 4.93 percent of the total corridor travel time. Table 9-3 Transit Corridor Travel Time in the Phase Two Test Eligible Trips with TSP Off Eligible Trips with TSP On TSP Granted Trips Standard Deviation Northbound 2′08″ 3′12″ 3′12″ Southbound 2′34″ 2′20″ 2′20″ Maximum Northbound 22′47″ 25′13″ 25′13″ Southbound 24′23″ 24′16″ 24′16″ Minimum Northbound 12′13″ 9′43″ 9′43″ Table 9-4 shows the transit travel times across the three biggest intersections on this corridor. The starting and ending points for intersection travel time calculation were defined as the points 100 ft upstream and 100 ft downstream of the intersection’s center point, respectively. Note that this definition is different from the one used for the Phase One test. The decision to use 100 ft upstream and downstream of the intersection’s center point was intended to exclude all bus stops from the intersection travel time calculation. This was not possible for the Phase One test because several near-side bus stops were too close to the intersections. All the bus stops in the Phase Two test corridor were on the far side and over 200 ft away from the center of the intersection. Southbound 40 28 200th Street Northbound 33 20 Southbound 34 31 220th Street Northbound 37 34 Southbound 23 26 Standard Deviation (sec) 196th Street Northbound 37 36 Southbound 27 23 200th Street Northbound 25 14 Southbound 24 19 220th Street Northbound 29 20 Southbound 22 26 As can be seen in Table 9-4, the SS-RTSP system saved transit travel times at all studied intersections except for the southbound direction of the 200th St intersection...