Traffic jams and air pollution are serious problems in many developing countries, including Vietnam. The transition from private to public transport is necessary, helping to reduce these issues. This study aims to assess the passengers’ perception and awareness of the current public transportation and estimate the people's willingness to pay for the transition from the current regular bus service to the Bus Rapid Transit (BRT) in the Mekong River Delta (MRD) Vietnam. The data in the paper were collected directly by randomly interviewing 120 people in Soc Trang city of MRD. Logit model based on Contingent Valuation Method was employed to determine the determinants of willingness to pay for BTR. The research results reveal that many factors need to be improved for the current conventional bus system such as safety level, bus stop quality, and security status on the bus. Notably, up to 90% of the respondents are willing to pay for upgrading the current bus service to a high-quality one (such as BRT) with an average price twice the current one. The research results also identify the factors affecting the payment decision including age, income, the number of personal motorbikes currently owned. Based on the research results, future policies should prioritize the implementation of the BRT system, which is one of the main drivers to reduce the number of motorbikes in Vietnam, contributing to improving the air environment in the future.