Estimation of Traffic Situation by Statutory Bus Probe Data

Abstract

Probe data collected by ordinary vehicles are being used to observe temporospatial change in travel times on road networks. However, the number of observations can be insufficient due to detouring by probe vehicles on congested road links, especially in provincial cities. The authors proposed a method for supplementing this insufficiency with estimated running trajectories of ordinary vehicles by correcting bus location system data and statutory digital tachograph data of buses at bus stops. On the other hand, differences in traffic conditions between the estimated running trajectories of ordinary vehicles and the real ones needed to be addressed. This study confirmed that these differences in traffic conditions could be decreased by applying the time-slice method into temporospatial meshes where interpolated expected travel speeds were set based on the above estimated running trajectories of ordinary vehicles. In addition, the precision of real-time estimation based only on the bus location system data was verified.