An analytical model for real-time estimation of travel times along signalized arterials was developed. The application of the model on two arterial sites and comparisons of the estimated travel times with simulated and field data show that the model accurately predicts travel times on the selected sites. In this article, we present several important extensions and refinements to the model including treatment of long queues and queue spillovers, and algorithms for signal priority to transit vehicles. We also describe the integration of the model into an archival data management system for continuous measurement and monitoring of traffic performance along arterials.