Yesterday, we found that light-rail systems in Houston, Minneapolis, Portland, Salt Lake City, San Diego, and St. Louis seemed to be energy efficient compared with automobiles. But are they really?
When transit agencies open light-rail lines, they don’t usually make significant reductions in bus service. Instead, they convert corridor bus lines to feeder buses for the light rail. Since many people end up driving to light-rail stations, these feeder buses end up carrying far fewer riders than the corridor buses that the light-rail replaced.
Thus, rail transit’s energy and CO2 cost per passenger mile savings are potentially offset by increased energy and CO2 costs per bus passenger mile. I first noticed this for Salt Lake City. The Utah Transit Authority brags about the great success of its light rail, and it did lead to a modest increase in total transit ridership (although ridership was growing even before it opened the line).
