Estimating Path Travel Time by Aggregating Link Travel Times Obtained through Dedicated Short Range Communication Probe Data

摘要

Korea Expressway Corporation (KEC) began utilizing vehicles equipped with the dedicated short range communication (DSRC) based electronic toll collection system as traffic probes for collecting path travel times, thereby reducing traffic congestion on highway. Since it is not always possible to obtain sufficient sample size for calculating certain path travel time in the DSRC system, KEC attempts to estimate the path travel time by the simple and progressive addition of link travel times on its component links as in past studies—often referred to as link based model (LBM). However, an assessment is lacking on how accurately the LBM estimates the path travel time. Hence, this study examines whether the LBM can be used for obtaining reliable path travel times. The analysis results reveal that the differences between the LBM estimates and the path travel times obtained from the probe vehicles traveling whole links on the path are less than 63 seconds. Thus, when the number of probe vehicles traveling whole links on its path is small, the aggregated link travel times proposed in this study can be used as a substitute for path travel times. Although it is anticipated that the analysis results are sufficient to provide the feasibility of the LBM in estimating path travel times, the results should be treated with caution because this study was based on relatively small samples due to data limitation.