In this paper, the environmental efficiency of the bus rapid transit (BRT) in Hanoi was analyzed through estimating the co-benefits of air quality, climate and health. First, the real-world driving data, instantaneous velocity versus time, in the city was collected using the global positioning system (GPS) technology with the signal update of 1 Hz. Then, a data processing procedure consisting of nine steps was applied to remove errors and to smooth the GPS data. After that, the processed GPS data was used to develop the typical driving cycle for BRT in Hanoi based on the Markov chain theory. Emission factors of air pollutants including CO, CO2, VOC, NOx, SO2, and PM10 were determined based on the developed driving cycle with the use of the International Vehicle Emissions (IVE) model. The health effect was estimated using the AirQ+ model. It is found that, compared to the regular buses, deploying the BRT in Hanoi can reduce the emissions of air pollutants 17.3–22.6 % and the amount of CO2eq emission up to 22.4 %. It is also indicated that at least 4.8 % of prevalence of bronchitis symptoms in asthmatic children aged 5–14 years, and 2.4 % of total mortality due to all causes except accidents in aged 30+ years in Hanoi can be reduced through deploying the BRT. Although the average speed of the current BRT in Hanoi is only 1.3 times higher than the regular bus, it could bring to significant benefits in terms of environment and health.