Experts say it will probably take years for such activities as air travel to return to normal. Meanwhile, governments will still have to figure out how to shore up aging infrastructure, alleviate traffic congestion, support mass transit and accommodate the flying public.

The Maryland Department of Transportation has proposed slashing nearly $3 billion from its six-year capital budget. The cuts include delaying $900 million in road projects and postponing construction of a $500 million baggage-handling system and terminal connection at Baltimore-Washington International Marshall Airport. The state also plans to temporarily scrap some service for commuter buses and MARC commuter trains, which have ridership hovering at about 10 percent of normal.

“Everything has been hit across our system,” Maryland Transportation Secretary Gregory Slater said. “We have to find the least amount of impact to people, but people will see and feel some of this.”

Slater said his agency is trying to