Now whenever you plan a trip using the BART QuickPlanner on our homepage, you can see how much 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. You’ll see the figure generated by our carbon calculator in the lower righthand side of the screen on your trip plan, below the map and the listing of your starting and ending points.

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)

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)

Note: BART CO₂ emissions are not included in this formula since no measurable emissions
result from adding one trip. BART train operation is 100% electric, and
67% of BART's power comes from clean hydro and renewable sources.

Download the spreadsheet (136k .xls)