That's true, but I don't think it makes much of a difference. I couldn't fix the angle, but here's the same picture with second and third images also zoomed in similarily: https://imgur.com/a/2GMcSlE
> Second, it assumes 1 occupant per car, but a full bus. More likely, each car will probably average more than 1 occupant, and buses will probably be less than half full, if not 25%.
Actually, below is an example for a few countries. Average number of persons in a car seem to be decreasing with 1.8 in the 80s, down to around 1.4 in 2005. At the same time average seat occupancy for buses seem to be around 70%. This matches what I observe everyday - vast majority of cars has only the driver inside.
https://www.eea.europa.eu/data-and-maps/indicators/occupancy...