Decision-making optimization model for the targeted sustainable maintenance of a complex road network

With the continuous expansion of highway construction scale, a complex road network can be divided into multiple subnetworks in accordance with any criteria, such as highway class, traffic volume, natural zoning, or administrative subdivision. To realize the targeted maintenance and local-whole optimization of a road network, this study proposes a new type of optimization model for road network maintenance decisions based on the idea of a bi-level programming model. The model fully considers the heterogeneity of a subnetwork, adopts different maintenance standards for targeted maintenance, establishes a whole network maintenance fund allocation model and a subnetwork unit maintenance decision-making (DM) model, and obtains the optimal maintenance scheme through the iterative calculation of a genetic algorithm. Finally, the model is applied to the maintenance DM of a highway network in Zhejiang Province and compared with the traditional DM model without subnetworks. Results show that the model developed in this study can better solve the maintenance DM problem of large-scale complex road networks and achieve the targeted maintenance scheme under limited maintenance funds. Hence, this model can help the sustainable development of road network maintenance.