Optimization Model to Determine Critical Budgets for Managing Pavement and Safety: Case Study on Statewide County Roads

This study develops a model that combines pavement and safety management system to utilize the resources more efficiently. Sometimes decision makers and road engineers need to estimate critical budgets to maintain and improve safety on roads most efficiently. The critical budget can be defined as the budget below which the rate of improvement (per million dollars) is higher compared with that above the budget. This paper develops optimization models to determine critical budgets for maintaining pavements and improving safety. The developed methodology is used to conduct a sensitivity analysis using an optimization technique (genetic algorithm) to determine the critical budget. Two critical budgets are determined from two models: pavement and safety. The primary factors in the model include pavement serviceability index, traffic volume, cost factor, roadway inventory, crash data, crash modification factor, and safety improvement countermeasures. The developed methodology uses linear integer programming to identify the list of preservation projects that provides the greatest benefit to society. The findings will help lawmakers to make funding decisions to preserve roadway networks.