Application of Driving Cycle for Emission Assessment between Cash and Electronic Toll Collection Systems: A Case Study of the Utraphimuk Elevated Tollway

Abstract

Currently, toll collection technology on the Uttaraphimuk Elevated Tollway is divided into two systems: manual toll collection (MTC) and electronic toll collection (ETC), each of which influences driver behavior-particularly in deceleration and acceleration patterns-resulting in different levels of pollutant emissions. This study aims to assess the environmental impact of both systems by applying the Bangkok Driving Cycle in combination with a camera analytics system to collect vehicle speed data at nine toll plazas along the Uttaraphimuk Elevated Tollway. Vehicle speed was used as the key indicator to estimate emissions of carbon dioxide (CO₂), carbon monoxide (CO), nitrogen oxides (NO_x), and hydrocarbons (HC) under both congested and uncongested traffic conditions. The results indicate that the ETC system significantly reduces emissions. Over the course of one year, it can reduce CO₂ by 71.97 tons, CO by 26.41 kilograms, NO_x by 20.55 kilograms, and HC by 2.41 kilograms. These reductions result from minimizing stop-and-go behavior near toll plazas. In contrast, the MTC system generates higher emissions due to the need for vehicles to decelerate and stop for toll payment. This study highlights the potential of the ETC system to reduce urban air pollution and support sustainable environmental policymaking through improved transportation infrastructure. However, the study focuses solely on gasoline-powered vehicles, as current traffic monitoring technologies cannot accurately distinguish between different vehicle fuel types.