Investigating the impact of highway electronic toll collection to the external cost: A case study in Taiwan

The implementation of electronic toll collection (ETC) on highways aims to reduce toll transaction time and thereby increase service capacity. In this paper, considering the separation of manual toll collection (MTC) and ETC lanes, a method is developed to estimate the carbon dioxide (CO2) emissions, transaction time, and the associated external cost incurred by vehicular traffic at four toll plazas on a northern-central highway in Taiwan. Three vehicle types are considered: passenger cars, buses and trucks. Results show that the CO2 emissions were reduced by 12.4% as the number of ETC lanes for all 4 toll plazas increased. The reduction of external costs fell by 60.1% in terms of value of transaction time, which will arguably lead highway authorities to actively promote ETC