Transit: Still a Good Idea

I can’t vouch for the statistics in the U.S. report, as we are asked to trust the author on the assumptions he makes to piece together from a half-dozen reports which he admits are lacking key bits of information. And I think he makes a mistakes in estimating emissions and trends, but let’s not quibble as this post already has enough statistics in it. It is, however, worth noting that even with these caveats, Table 1 of the report still shows that transit has significantly lower emissions per passenger mile traveled – contrary to Reynolds’ spin.

And while I won’t claim to know much about the U.S. stats, according to Natural Resources Canada, public transit systems in Canada emit an average of 69 grams of carbon for every kilometer traveled by a passenger (this ranges from 156 grams/passenger kilometer for diesel buses to 21 grams for light rail). Meanwhile, the average Canadian vehicle emits 350 grams of carbon per km, so you’d have to put 5 people in every car for it to match transit. A Prius puts out about 120 grams/km, so you’d need two people in every Prius.

You may be able to find a bus route somewhere in Canada whose emissions per passenger kilometer are worse than a car. But even that likely misrepresents the big picture, because you have to look at transit systems as a system. A lightly occupied bus may feed a subway that carries a lot of people, so the system is much more efficient overall at moving people from Point A to Point B – but the subway doesn’t work without buses to bring people to it.

And with gas prices increases increasing transit ridership (which further reduces the carbon emissions per passenger kilometer as you put more people on each vehicle), now is the wrong time to scrap the bus. Especially for people who are finding they can’t afford to fill up the tank.

by Keith Stewart