A two-step travel delay estimation method for macroscopic urban traffic models

Travel delay is one of the key parameters in macroscopic traffic models. Especially in urban traffic networks, sensors are only located near the intersections, the travel status between intersections is hard to determine. Some original macroscopic urban traffic models use free-flow speed to estimate the travel delay, while other studies use a one-step macroscopic fundamental diagram to estimate the travel delay. The former models do not consider the speed-density relations, and the latter models use the mismatched density information. In this paper, we propose a two-step travel delay estimation method to reach a better estimation of system states without losing efficiency. We describe the estimation method in discrete domain. Then we verify our algorithm in the Simulation Urban Mobility (SUMO) platform together with other methods. The results show that the two-step estimation method can reach a better overall result compared with other methods, and the computational time is as expected.