STM - Society in motion
By taking the bus instead of your car, you are cutting your polluting emissions by more than half. May 2, 2010
When comparing the emissions of a car ride with those of a bus ride, several data are taken into account:
- the average emissions of a car per travelled kilometre, as published by Transport Canada;
- the average number of persons per car according to the Origin-Destination survey (1.25 person);
- the emissions by all STM buses for all hours of transit service;
- bus ridership and the average length of a bus trip (km-passenger).
Polluting emissions include :
- carbon monoxide (CO)
- nitrogen oxides (NOx)
- sulphur dioxide (SO2)
- volatile organic compounds (VOC)
- total suspended particulates (TSP)
Polluting emissions are not produced in the same proportion for buses and cars.
Our calculations show that, when combining all hours of STM service, they are 2 to 10 times lesser for a bus than for a car, depending on the pollutant.
During rush hour, emissions are 7 to 44 times lesser for a bus than for a car. This is based on an average of 65 passengers per bus, which is equal to 50 cars (65 persons divided by 1.25).
