Civil and Environmental Engineering, College of Engineering
Transportation Research Institute
Henry Liu, PhD, is Professor of Civil and Environmental Engineering in the College of Engineering and holds a secondary appointment of Research Professor in the U-M Transportation Research Institute (UMTRI). Prof. Liu is also Director of the Center for Connected and Automated Transportation (Regional 5 UTC).
Prof. Liu’s research is in the areas of traffic network monitoring, modeling and control. His recent work has focused on traffic flow modeling and simulation, traffic signal control and optimization, traffic management under network disruptions and equilibrium traffic assignment. Prof. Liu is the co-founder and chairman of the advisory board for SMART Signal Technologies. The SMART Signal (Systematic Monitoring of Arterial Road Traffic Signals) is a real-time arterial performance monitoring system that uses traffic data from existing signal systems. SMART Signal simultaneously collects event-based high-resolution traffic data from multiple intersections and generates real-time signal performance measures, including arterial travel time, number of stops, queue length, intersection delay and level of service. “Traffic engineers can use this information to improve traffic flow on roads controlled by traffic lights—reducing congestion and saving drivers both time and fuel. SMART Signal could also give drivers a more accurate prediction of travel times by accounting for time spent waiting at traffic lights,” states the University of Minnesota Intelligent Transportation Systems website. The system is now deployed at more than 100 intersections on major arterial corridors in Minnesota and Pasadena, California. Arterial corridors are roads where many cars can move from urban centers to high-capacity freeways.