Gasoline prices have fallen more than 40 percent since the end of June thanks to the collapse of global oil prices. That makes this the perfect time for Congress to overcome its longstanding terror of offending the nation’s motorists and raise the tax on gasoline and diesel fuel. The results could only be beneficial: for the nation’s roads, bridges and transit systems, which badly need repair; for the budget; and, to the extent that higher taxes encourage greater fuel efficiency, for the climate.

The federal excise tax of 18.4 cents per gallon on gas and 24.4 cents on diesel has not been increased since 1993. That has severely shortchanged the Highway Trust Fund, which is expected to run out of money in May if Congress does not transfer more into it or raise fuel taxes. If the federal tax on gasoline had simply kept up with inflation, it would be 30 cents today.

There is little doubt that the nation’s road and transit systems could use more help. The American Society of Civil Engineers gave them a nearly failing grade of D in 2013; the state of bridges is somewhat better, earning a C-plus. The country’s inadequate road and transit systems cost it billions through increased delays, extra fuel costs and auto repair bills. Poor road conditions are also said to play a significant factor in about one-third of all traffic fatalities, or about 10,000 deaths a year.

Some lawmakers, including some Republicans, are concerned enough about these trends to discuss an increase in fuel taxes. Senator Bob Corker, Republican of Tennessee, has proposed increasing the tax, and Senator James Inhofe, Republican of Oklahoma and a big supporter of the energy industry, has said he is willing to consider it. Some state leaders are also considering raising their own fuel taxes. Lawmakers in Michigan have put a gas tax increase on the ballot for a May election, and Iowa lawmakers are also talking about a higher tax.