Connected to reducing congestion, it is often put forth that public transit is necessary because it reduces carbon emissions by moving people from single-occupancy vehicles into transit. While I grasp the argument that twenty people riding together on a bus potentially emits less carbon than twenty people riding in individual automobiles, I am skeptical of the overall claim. I have never seen a study that credibly correlates increases in transit use with an overall reduction in carbon emissions, largely for the same reasons that increasing transit use, or building more road capacity, does not
...more
