# Applying Topological Information for Routing Commercial Vehicles Around Traffic Congestion
## 1 Introduction
Rerouting strategies are intended to divert truck traffic from congested facilities, expedite traffic flow, decrease conflicts between passenger vehicles and trucks, and improve the operation and safety of limited urban highways. Traffic diversion strategies that channel truck traffic to a potential alternative route can mitigate congestion. The alternative route then carries both the diverted traffic and its regular traffic load. Therefore, the evaluation of truck traffic diversion options should consider the safety and efficiency of the overall network. Although traffic diversion strategies are implemented in many regions, only limited attention has been paid to identifying criteria for selecting the optimal alternative route for truck traffic. Current traffic diversion strategies do not consider whether an alternative route can accommodate truck characteristics and meet maneuverability requirements. The selection criteria for alternative truck routes should be carefully defined so that they consider truck characteristics, and optimal routes should be selected that can efficiently accommodate truck traffic. Most previous studies of traffic diversion have focused on enhancing traffic conditions for passenger vehicles rather than on enhancing conditions for trucks. Hence, limited consideration has been given to assessing the economic, social, and environmental impacts of truck traffic diversion strategies on the performance of the selected alternative routes. A competent truck rerouting operation requires precise planning and substantial resources throughout the implementation. Given declining resources for traffic management, it has become increasingly crucial in practice to ensure there is valid justification before implementing a rerouting strategy. This study develops a decision-support system to aid traffic managers in efficiently making such decisions by considering several factors: (a) the predicted incident clearance time, (b) the predefined alternative route selection criteria, and (c) the resultant benefits from reduced delays and lower fuel consumption. The proposed decision-making tool assists transportation planners in reaching truck diversion decisionsthat are based on observed traffic conditions and that improve the safety and efficiency of the traffic network. The limitations noted above, together with the infrastructure expansion investment gap in the U.S., indicate a need to embrace alternative strategies to detect, manage, and efficiently mitigate traffic congestion. The use of an efficient truck traffic diversion strategy during incident-induced congestion provides safety and mobility benefits to highway users. A reliable and comprehensive framework is needed for evaluating such traffic diversion strategies during nonrecurrent congestion. The application of appropriate diversion criteria that include truck value-of-time (VOT) analysis, fuel consumption measures, safety studies, environmental impact analysis, and noise control considerations can lead to the selection of an alternative route that reduces travel time, meets truck operations restrictions, and sustains an acceptable level of service on the alternative route. The proposed framework provides a decision-support tool to help decision makers and traffic management centers cope more efficiently and effectively with nonrecurrent congestion on highway networks. The remaining sections of this paper are organized as follows: Section 2 presents a review of the literature related to rerouting strategies and the various processes for mitigating congestion problems. Additionally, it discusses the application of geographic information systems in transportation. Section 3 describes the methods for collecting, cleaning, and preparing the data for analysis. It also discusses suitable statistical approaches and techniques for analyzing the performance of the developed framework based on the available data. Section 4 presents methods for preparing a road network dataset and historical traffic data and setting alternative route selection criteria.