Optimal Phase Ordering of Traffic Signals to Reduce Stopped Delay

Congestion in road network results in prolonged travel time to the general public, adds extra cost to economic activities, and raises the pressure on road safety and environment. Traffic signals are an elementary component of all urban road networks and play a critical role in controlling the flow of vehicles. However, current road transportation systems and traffic signal implementations are very inefficient. The objective of this research is to evaluate optimal phase ordering within a signal cycle to minimize the average waiting delay of vehicles and thus in turn minimize fuel consumption and greenhouse gas (GHG) emissions. Through extensive simulation analysis, we show that by choosing optimal phase ordering, the stopped delay can be reduced by 40% per car at each signal resulting in a saving of up to 100 gallons of fuel per traffic signal each day.