Pseudo real-time evaluation of adaptive traffic control strategies using hardware-in-loop simulation

A pseudo real-time simulation system that can be used for evaluating intersection control strategies is presented. For this research, a microscopic traffic simulator and an interface device, which connects the simulator to a 2070 traffic controller, was developed. The interface device consists of a commonly available 8255 digital I/O card, the newly developed signal converter for two-way translation between TTL level signals and the open-collector outputs, and a software module to link the traffic simulator to the I/O card. The resulting virtual-intersection system makes it possible to directly implement new control strategies into the advanced traffic controller and evaluate their performance in a pseudo real-time environment. As an example application of the new pseudo real-time simulation environment, the operational feasibility of an adaptive control strategy, which is based on a direct control approach with link-wide congestion index, was evaluated using the proposed system.