Travel time, speed, and delay analysis using an integrated GIS/GPS system
The backbone of any successful Integrated Traffic Management System (ITMS) for a metropolis is reliable, accurate, and real-time data. Travel time, speed, and delay are three of the most important factors used in ITMS for quantifying, monitoring, and controlling congestion. Global Positioning Systems (GPS) have recently become available for civil applications. As it provides real-time spatial and time measurements, it has an increasing use in conducting different transportation studies. This paper presents the application of GPS in collecting travel time, speed, and delay information on 64 major roads throughout the State of Delaware. A comparative statistical analysis was performed on data collected by GPS method, with data collected simultaneously by the conventional method. The GPS data proved to be at least as accurate as the data collected by conventional methods and was 50% more efficient in terms of manpower. Moreover, the sample-size requirement was determined to maintain 95% confidence level throughout the controlled test. Statistical trend analyses for the data collected from 1997 to 2000 are also presented and applications in the overall ITMS area are discussed.Key words: global positioning system, geographic information system, travel time and delay studies.