While this may be seen as a boon to public transportation, it is not without its unfortunate downsides. The cost of fuel and electricity are at recent highs and climbing. Building materials for system expansion are also on the rise. Only a quarter to a third of the actual cost of a fare is paid by the rider; taxes and government budgets account of the remainder. In some states, like Rhode Island, the public transit system relies on the state’s gas tax. This creates a kind of mad circle in which commuters buy less gas to instead use mass transit more—and the increased ridership actually results in a revenue shortfall. [Via New York Times]