Applications of Global Positioning System in Traffic Data Collections

This paper demonstrates that GPS is an efficient tool in recording vehicle position and speed values. The dynamic feature of the GPS collected data enables the traffic engineers to obtain the precise profile of vehicle speed as well as the geometric layout of roadway sections, intersections, and work zones. With the GPS data, the average travel speed on a given roadway section with or without intersections or work zone can be calculated. It is also presented that the vehicle deceleration and acceleration rates caused by intersections and work zones can be readily calculated with high accuracy using the GPS data. Moreover, traffic delays and exact queue lengths can also be obtained through the GPS collected traffic data. The measurements of vehicle speed profiles and traffic delays can be applied to a series of intersections as well as to an isolated intersection.