Comparison of Two Fundamental Average Travel Time Estimation Methods Based on Probe Car Data

Based on probe car data, two fundamental average travel time estimation methods that are commonly used in engineering applications were compared. The first method is named ‘average instantaneous speed method’, it calculates the arithmetic mean value of instantaneous speeds of all probe points during the estimation interval (usually 5 minutes) on the target link. The second method is named ‘average travel time method’, it estimates individual probe car travel time based on two probe car points that are respectively nearest to the two link sections of target link. VISSIM was used to compare the performance of these two methods using 25 and 30 second sampling intervals. With an 8% penetration rate of probe cars, analysis of the results showed that the average travel time method performs better than average instantaneous speed method under a borderline traffic state. In the end, research conclusions and the possible further related research were brought forward.