Optimally Locating Weigh-in-Motion Stations and Truck-Prohibited Roads for Mitigating the Impact of Overweight Trucks

Weigh-in-motion (WIM) stations are effective but expensive tools for the monitoring and enforcement of truck weight regulations. Faced with the increasing challenges of maintaining highways with ever shrinking financial resources, traffic authorities may need to couple WIM stations with other cost-effective measures for regulating truck weights. This study explores the idea of integrating WIM stations and truck-prohibited roads to reduce the impact of overloaded trucks on highway pavements and bridges. The problem of optimally locating WIM stations and truck-prohibited roads is formulated as a bilevel programming model. The upper-level model mimics the decision-making behavior of the traffic authority, whose aim is to determine the optimal locations for the deployment of WIM stations and the selection of truck-prohibited roads so as to minimize the total cost while considering route choices of overweight trucks. The lower-level models are used to determine the least cost paths for the overweight trucks of different origin-destination (OD) pairs in response to the authority's decisions in the upper-level model. A heuristic that iteratively solves the upper-level and the lower-level models is developed to efficiently solve the bilevel model, which is characterized as NP-hard. The proposed model and heuristic were evaluated using test instances generated based on the Nevada road network. The results demonstrate the advantage of using hybrid or multiple enforcement measures to prevent damage to the road network by overweight trucks in comparison with the traditional WIM-only approach.