Green transportation implementation through distance-based road pricing

The implementation of electronic toll collection (ETC) over freeways not only enables nonstop traffic flows through toll collection zones but also facilitates more flexible schemes for road pricing, such as distance-based and time-based schemes, as both the on-ramp and off-ramp time stamps of a trip can be detected. Based on such an ETC environment, this study develops a road pricing model which considers the perspectives of road users, the government, and the ETC agent, seeking to attain greener transportation by leveraging the external costs related to environmental impact and accident potential. Thereupon, a Green Safety Indicator (GSI) is proposed to comprehensively account for the service level of freeway traffic. The optimal solution for the benefits generated from three scenarios are determined against GSI-based equilibria, which can maintain the revenue for the government, offer the ETC agent higher profits, and allow road users off-peak discounts, thereby promoting a tripartite win-win situation among stakeholders.