Using available data for San Diego and comparative metropolitan areas, Insight San Diego measured percentage of residents using public transportation, annual hours of traffic delay, and amount of CO2 emitted in traffic to develop the Transportation grade. More residents using public transportation to get around, generally means fewer emissions,
More residents using public transportation to get around, generally means fewer emissions, less fossil fuels used for transportation and smarter land use patterns. (7) Increased use of public transportation also can lead to less annual hours of traffic delay per resident, with similar outcomes related to emissions and use of fossil fuels.
CO2 emitted in traffic is not only a climate change driver, but also contributes to air pollution and unhealthy air days. On-road transportation continues to be the largest emitter of CO2 in San Diego, representing more than 40% of emissions in the County. (8)