The financing of highways, mass transit and other transportation improvements faced two major roadblocks last week. One was temporarily averted; the other was not.

Congress and the White House agreed on an $8 billion reprieve for the nearly bankrupt federal highway trust fund. The infusion of general fund money will keep the trust fund limping along well into next year, but it's no permanent fix.

State transportation programs didn't fare as well. In Maryland, declining tax revenue means more than $1 billion less will be spent on roads and public transportation over the next six years. That's a major hit, particularly to efforts to ease congestion from thousands of military-related jobs coming to Fort Meade and Aberdeen.

The problem at both the state and federal levels is not merely a lack of funds but a maddening dependence on people driving their cars more and more to generate the needed revenue.

The biggest sources of money for Maryland's transportation trust fund, for example, are the vehicle titling tax, the gas tax and the state's biennial registration fees. Car sales are way down and so is driving, and when people do buy a car it's more apt to be a smaller, less expensive car that uses less fuel and is cheaper to register.

Combine this trend with rising construction costs - asphalt alone has more than doubled in price in recent years - and a crisis is at hand. In an era of high gas prices, global warming and concerns over car-dependent sprawl development, this is a time when government should be investing record amounts in rail and other forms of transit, not reducing budgets to maintenance levels.

The next president and Congress will need to come up with a permanent fix, a dedicated source of transportation revenue and a willingness to invest much more in energy-efficient, environmentally friendly transit. At minimum, the federal 18.4-cent gas tax (which hasn't been raised in 15 years) ought to be indexed to inflation.

On the state level, Gov. Martin O'Malley and lawmakers need to take similar actions and not just pursue stopgap solutions such as raising motor vehicle fees. It's nonsensical to make Maryland's transportation future so dependent on keeping people on the road as much as possible.