Citation

Mussa R, Upchurch J. J. Transp. Res. Forum 2000; 39(4): 117-127.

Copyright

(Copyright © 2000, Transportation Research Forum)

DOI

unavailable

PMID

unavailable

Abstract

This paper reports on an analytical model, developed to evaluate the detection of freeway incidents by drivers using a vehicle to roadside communications (VRC) system. The VRC system uses radio frequency communications between a tag installed in a vehicle and a reader installed on the roadside. A driver with a tag capable of digital messaging activation can report an incident to a highway agency via the roadside reader. The Freeway Simulation model was used to simulate shoulder and lane-blocking incidents occurring under various traffic flow rates. The proportion of tagged vehicles in the general vehicle population and the degree of the drivers' reporting propensity were introduced as control variables. A binomial probability model was applied to determine the probability of an incident being reported by drivers passing an incident. Results show that all simulated incidents were detected in a short time with high probability of detection and that in moderate to heavy traffic, most simulated incidents could be detected in less than 2 minutes if even a small number of vehicles had a tag. Results further show that other factors affecting the detection performance of this system were drivers' willingness to report incidents, the spacing of the readers on the freeway, and the distance from the incident to the downstream reader station.