Improving User Equilibrium via Public Service Advertising

The user equilibrium is a classic model for travelers' choices in transportation networks, but it is widely considered inefficient due to travelers' selfishness. Supposing there is an ideal central authority to fully coordinate the traffic, the total travel cost in the whole network can be minimized, which is usually modeled as the system optimum. This can serve as a benchmark for improving network efficiency. Smart phones provide route advice from transportation apps. We want to know whether such public service advertising from transportation apps improves travelers' own travel cost and the total travel cost from the systematic view. This paper establishes a mathematical model to describe travelers' routing choices and show their effects on travelers' routing decisions. We explore how it can improve the network efficiency, and give suggestions on making better use of transport apps. Numerical examples show that public service advertising can help alleviate traffic congestion.