GPS MEASUREMENT OF TRAVEL TIMES, DRIVING CYCLES AND CONGESTION

In the past few years, various types of GPS devices have been developed for use in connection with travel surveys of various types. This paper describes an application in Sydney, Australia, in which GPS devices were used to collect data on automobile trips within the urban area, with the goal of developing information about travel times, driving cycles, and the incidence and severity of congestion. The paper describes steps taken in designing the sample in both cases, and presents the results of the data collection, together with estimates of the sampling errors on segment, link, and corridor travel times. It is concluded that GPS technology represents an accurate and inexpensive method for collecting travel time and speed information, even if samples are relatively small. (a)