Carbon Calculator


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 are the notes on the formula we use to calculate the CO2 savings generated by your BART trip:

Carbon Calculator Notes

Formula: Carbon Dioxide Saved by BART Trip = ((Road Distance / MPG) * Pounds of CO2 emitted per gallon of gas) - (Pounds of CO2 emitted by BART per passenger mile * Track Distance)

BART Track Distance = Track distance between stations. (Source: Charlotte Barham BART OPD) 

Road Distance = Road distance between stations. (Source: Galilee Enterprise using Freeway 2009 software) 

MPG = 21.6.  The miles per gallon (MPG) estimate is based on fuel economy of the light duty passenger vehicle fleet as a whole including both new and existing vehicles (Source: US Environmental Protection Agency Greenhouse Gas Emissions from a Typical Passenger Vehicle – Page 2, http://www.epa.gov/otaq/climate/documents/420f14040.pdf)

Pounds of CO2 emitted per gallon of gas = 19.592 (Source: US Environmental Protection Agency Greenhouse Gas Emissions from a Typical Passenger Vehicle, Page 1 - 8,887 grams, http://www.epa.gov/otaq/climate/documents/420f11041.pdf

Pounds of CO2 emitted per BART passenger mile  = .13. based on 2007 Annual Passenger Miles = 1,367,923,924 and annual BART emissions = 82,438 metric tons (Source: BART Greenhouse Gas Inventory, December 2008, ARUP)

 

Download the spreadsheet (80k .xlsx)