https://www.sciencedaily.com/releases/2019/08/190826143407.htm

In a paper published in Environmental Research Communications, University of Utah researchers Daniel Mendoza, Martin Buchert and John Lin used tap-on tap-off rider data to quantify the emissions saved by buses and commuter rail lines, and also project how much additional emissions could be saved by upgrading the bus and rail fleet. The study was conducted in cooperation with the Utah Transit Authority and the Utah Department of Environmental Quality, Division of Air Quality.

Mendoza and his colleagues are certainly not the first to ask how much pollution public transit can save. But a couple of recent technological advances have enabled them to answer the question with a level of detail previously unparalleled.