» Transit’s environmental credibility depends on a switch away from carbon-based fuels — And a renewed sense that well-designed public transportation produces density.
Straight to the point: There are a panoply of choices to be made when investing in public transportation, but there is never an excuse for minimizing the negative environmental effects of a transit vehicle.
Some American public transportation agencies run bus fleets that consume on average a gasoline-equivalent 25 miles per gallon. This means — and this must be interpreted literally — that there are plenty of cars that, when driven from one point to another, are less carbon-intensive even with only one passenger than buses running the same route.
This fact is a disappointing one for transit advocates who would promote the idea that transit is, on face value, always more ecologically conscious than private transportation. It is a letdown to discover that the simple formula — more people in one vehicle = more fuel efficiency, thus public transportation > automobiles — doesn’t work out when those transit vehicles average fewer than 10 passengers at a time.
To the anti-transit zealots of the world like Wendell Cox, this fact is evidence that governments would be more likely to encourage decreases in carbon production by ridding cities of transit and instead pushing people into hybrids and other mildly polluting cars. That argument, however, completely ignores the fact that transit promotes communities that are denser, more walkable, and in general less energy consumptive — even if trains and buses sometimes feature lower fuel efficiencies than the newest Toyotas and Hondas.
To transit promoters like Jarrett Walker, this same information is indicative of the fact that transit planners must take to heart a variety of rationales when considering how to choose routes; the most ridership-heavy routes (those that would feature the highest average fuel efficiency) are not necessarily the most politically or regionally prioritized investments — which means that vehicles can often be found running with few passengers on board. Transit that runs all the time and to many places — and which therefore is frequently empty — is absolutely necessary to advance the kind of transit-dependent population that consumes less energy overall.
Nevertheless, the limited fuel efficiency of the fleets of many transit agencies is troubling because even if public transportation is effective in promoting better land uses, if buses and trains continue to spew pollutants, we’re not doing enough to address the underlying environmental consequences of transportation use. Indeed, while the adoption of hybrid-electric buses by many transit agencies is a step forward, the vehicles continue to emit carbon into the air — a problem that shouldn’t be side-stepped.
Full-scale electrification of bus routes and installation of catenary along train lines should be encouraged to further the environmental credentials of public transportation — as long as power providers increase the supply of renewables in the electricity mix. For cities, this clears the air as power is produced elsewhere (rather than in the vehicles, on the street). Overall, efficiencies are increased since centralized power production is more efficient than burning fuels vehicle-by-vehicle.
As automobiles become more and more efficient, buses and trains must be able to keep up — and the best way to do that is to go electric. To suggest that the poor fuel efficiencies of transit are merely a consequence of the realities of decision-making in the field is an attempt to make the issue go away, when in fact we should be addressing it straight-on.