| This research uses computer simulation to investigate the effect of detector location on the ability of a system to monitor traffic characteristics (flow, speed, occupancy) and from them estimate link travel characteristics (link speed, travel time, intersection delay).; A three-mile section of roadway in the Phoenix metropolitan area (part of the AZTech ITS Model Deployment Initiative) is simulated using the program CORSIM. Four detector locations within each major link are analyzed. One detector location is downstream of a major intersection; the other three locations are upstream of a major intersection. Statistical techniques, in the form of regression analysis, are used to evaluate the various dependent and independent variables.; Results of the analysis indicate the link travel characteristics are unique to each link on the network. Of the variables examined, there is no one singular relationship that can be used to predict link travel characteristics. Further, there is no particular detector location that proved to be superior to all other detector locations.; Detectors located downstream of major intersections can use traffic flow to predict link travel time with reasonable accuracy. Detectors located upstream of major intersections can use spot speed or detector occupancy to predict link travel speed with reasonable accuracy.; Detection is not required in every lane. In all cases, link travel characteristics were still able to be determined with reasonable accuracy with detection in only one of the lanes.; The spacing of detectors can be critical to the operation of a system. The research showed that detector data obtained on one link could not accurately predict link travel characteristics on an adjacent link. |
