Several studies have compared the arterial signal timings optimized by transyt-7f and passer ii. The comparisons, however, were based on simulated results. In this study, the transyt-7f timing plans were compared with the passer ii timing plans based on operational characteristics, field results, and simulated results. These comparisons were possible because (a) the signals on two arterials in san francisco were optimized by transyt-7f and implemented in 1987, (b) thesame signals were retimed by passer ii and implemented in 1988, and(c) before-and-after studies were conducted. From the field results, the overall effectiveness of transyt-7f and passer ii was about the same in terms of travel time and stops along the arterial (excluding cross streets). On one of the arterials, the offset pattern and operational characteristics of the transyt timing were very differentfrom those of the passer timing; on the other arterial, they were very similar. The transyt-7f simulated travel times were reasonably close to the field travel times. However, the simulated measures of effectiveness in general were inclined in favor of the timing plans optimized by transyt-7f. The field data for travel time were reliableand easy to collect. Statistically, one to five samples were required to attain a 95% level of confidence for the example arterials, each with 30 or more signalized intersections. This paper appears in transportation research record no. 1324, Communications, traffic signals, and traffic control devices 1991
Samenvatting