Whenever you use the BART QuickPlanner, the lower right corner of the results page will show the amount of carbon dioxide (CO2) you save when you take BART instead of driving.
CO2 is produced by the burning of fossil fuels, like the gasoline in your car, and it is one of the greenhouse gases related to global warming. Here's the formula we use to calculate the CO2 savings generated by your BART trip:
(Distance / MPG) * (Pounds of CO2 emitted per gallon of gas) – (Pounds of CO2 emitted by BART per passenger mile * Distance)
Distance = track distance between stations. (Source: BART)
Miles per gallon (MPG) = 20.3. Based on fuel economy of passenger cars and light trucks, weighted by vehicle miles traveled for passenger cars and light trucks. (Source: US Environmental Protection Agency)
Pounds of CO2 emitted per gallon of gas= 19.4 (Source: US Environmental Protection Agency)
Pounds of CO2 emitted by BART per passenger mile = 0.13 (Source: BART Greenhouse Gas Inventory, December 2008)
Download the spreadsheet (136k .xls)
