Rep. John Lewis (D-GA) is proposing today to make a small but crucial change in federal transit policy by requiring the nation’s Highway Trust Fund to keep the interest money it accrues, rather than give it up for the government’s general use.

Rep. John Lewis (D-GA) Photo: politicalkudzu.com.

Which brings up an even more crucial question: Why is it a good thing to give the Highway Trust Fund more cash?

For starters, the name of the 53-year-old fund is pretty misleading. Funded by the 18-cent-per-gallon gas tax, the highway trust fund (HTF) provides money not only for new roads, but also for mass transit.

Though public transportation receives a criminally paltry 2.86-cent share of gas tax proceeds, the HTF accounts for about 80 percent of the government’s total spending on mass transit. Strange as it sounds, then, keeping the HTF fiscally healthy is an important first step in giving Washington’s transportation policy a much-needed 21st-century shakeup.

In fact, the mass transit account of the HTF is at risk of exhaustion by 2012 — and that still puts it in better shape than the general highways account, which faces insolvency as soon as this fall.

Lewis’ bill would keep all transportation money from being diverted to patch other budget needs, thus strengthening the mass transit account and increasing the likelihood that the HTF funding crisis doesn’t scare Congress into postponing the entire debate over federal transportation reauthorization.

In short, the more quarters that can be scrounged from between the nation’s couch cushions for the HTF, the more likely we are to see a congressional transportation bill that reorders the nation’s priorities to reflect 21st-century reality.