Link-Journey Speed Estimation for Urban Arterial Performance Measurement Using Advance Loop Detector Data under Congested Conditions

Abstract

Travel speed ties directly to travel time, so it is an important measure for quantifying arterial performance. However, accurately estimating link travel speed for urban arterials is difficult because of traffic fluctuations and stop-and-go conditions caused by signal control. This research proposes a two-step empirical approach to effectively estimate the link-journey speeds using only advance loop detector outputs. The first step is to estimate the spot speed on the basis of advance loop measurements using Athol’s algorithm. The robust regression technique can be used to calibrate the speed estimation parameter (or