STM - Society in motion
How do we calculate that Travelling by public transit emits 20 times less CO2 than travelling by car? March 14, 2011
The calculation used to arrive at this result is based on several factors.
1. The Origin-Destination study conducted in 2008 enabled us to determine that the average distance travelled during a trip on the STM network is 8.3 km, of which 5.3 km occurs on the métro. We also learned that the average number of passengers in a car is 1.3.
2. Our calculations are based on a rush hour scenario with an average of 65 passengers per bus. We can then calculate the CO2 emissions from the bus divided by 65 to obtain the emissions per passenger-km. As for the métro segment, we know that the métro emits no CO2, as it is 100% electric.
3. We then compare the emissions for the same 8.3-km trip carried out by a car with 1.3 passengers.
Fuelling with biodiesel February 11, 2009
In November 2007, the STM began using biodiesel – regular diesel to which is added “methyl diester,” a biofuel made from recycled cooking oils and animal fats – in its buses and service vehicles. Since June 2008, the entire bus fleet is fuelled with biodiesel with concentrations of biofuel of up to 5%, as it can be adjusted according to weather conditions. The use of biodiesel has lead to reducing GHG emissions by more than 3500 tons in 2008, equal to more than 600 cars each running 20 000 km a year.
By being bold and also wielding considerable purchasing power – it takes 50 million litres of fuel each year to operate its buses – the STM has paved the way for the biodiesel market in Québec, leading both towns and transit in the drive to being ever greener.
For the STM, not all biofuels are created equal. By choosing a biofuel produced from recycled cooking oils and animal fats instead of corn crops, the STM takes yet another small action for a better planet.
