An Optimized Route Assignment for Preventing Traffic Jams

Frequent traffic jams are a common problem in large urban areas and despite real-time operation, contemporary traffic control (i.e., navigation) systems do not fully succeed in solving this problem. This situation motivates traffic assignment research aimed at optimal usage of infrastructure, that is, minimization of travel time. However, achieving this goal in real-time requires a departure from traditional approach and an enhancement of the predictive and preventive abilities of control and navigation systems. To this aim, the paper presents an efficient solution for an optimized route assignment given the set of available routes between two city zones. Unlike other methods, mostly working on link (graph edge) level, the proposed solution works on route (graph path) level and is based on estimation of the expected (average) travel times. This enables the application of two efficient algorithms for optimization of vehicle distribution according to two important criteria, that is, both Wardrop’s principles. The most prominent characteristics of the proposed algorithms are linear complexity with respect to the number of vehicles (traffic flow), linear and quadratic complexity with respect to the number of routes for user equilibrium and system optimization, respectively, simplicity, and absence of any numerical issues, which makes them suitable for real-time traffic management. The theoretical results have been confirmed by diverse evaluations using synthetic models and in a case study using the city of Zagreb as a real world example. The proposed concept is universal, inexpensive, and quickly implementable as an upgrade to the existing traffic control or navigation systems.