Travel-time estimation using cross-correlation techniques

This paper demonstrates the viability of using cross-correlation techniques with inductance loop data to measure the propagation time of traffic. The propagation time between loops separated by 0.5 miles is measured by using time-averaged activation counts (‘volume’) from inductance loops. The resulting time delay is used to estimate the mean speed. This independent speed estimate can be used to improve the volume/occupancy ratio estimate of speed from single loops.