Images are unavailable offline. Empty roads leading into and out of the Las Vegas strip are seen as the spread of coronavirus disease continues, Nevada U.S., April 9, 2020. SHANNON STAPLETON/Reuters

America’s roads are a lot less congested, due to coronavirus shutdowns that have kept millions of commuters, shoppers and vacationers parked at their homes.

While that makes it easier to patch potholes, it also could spell trouble for road and bridge projects. The longer motorists remain off the roads, the harder it will be for states to afford repairs in the months and years ahead.

Reduced traffic volumes are expected to cause a sharp drop in state revenue from fuel taxes, tolls and other user fees that could force delays for thousands of projects nationwide unless the federal government intervenes.

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“This is a critical need at the national level,” said Patrick McKenna, president of the American Association of State Highway and Transportation Officials and director of Missouri’s transportation department.

Leaders of state transportation agencies have asked Congress for an immediate $50 billion to prevent major cuts to road and bridge projects over the next year and a half. As an economic stimulus, they also want Congress to authorize a long-term plan that doubles the amount of regular funding going to state transportation agencies.

The request comes as a majority of Americans are under government orders to remain home to try to slow the spread of the virus that causes the COVID-19 disease. For many, the virus causes mild to moderate symptoms such as a fever or cough. But for some, especially older adults and those with existing health problems, it can lead to more severe illnesses and death.

A $2 trillion federal stimulus package enacted last month included billions for public transit systems, publicly owned commercial airports and Amtrak passenger train service – all of which have seen sharp declines in customers as a result of the coronavirus. But it earmarked nothing for state highways and bridges.

Republican President Donald Trump and Democratic House leaders have expressed support for a big infrastructure spending plan as part of another economic stimulus bill. But similar pronouncements in previous years have failed to produce results.

In the meantime, some road and bridge projects already have been put on hold.

The North Carolina Department of Transportation has slashed its expected construction projects from 131 down to 38 for the upcoming budget year, a $2 billion reduction.

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Ohio has delayed projects until next year on interstate highways in Columbus and Cincinnati because of the expected decline in fuel tax revenue.

Faced with a budget shortfall, Missouri has postponed $46 million for 18 road and bridge projects that had been priorities for local governments. As many as 299 additional projects valued at $785 million could be at risk without federal help, McKenna said.

Among the immediate deferments: a new highway interchange to provide direct access to the expanded Ozarks Medical Center in West Plains. The centre’s hospital, physician and specialty clinics are among the area’s largest employers, serving about 40,000 patients in eight rural counties of southern Missouri and northern Arkansas.

The state had allotted more than $1.2 million to cover half the road construction costs. The other half was to come from local transportation sales tax revenue, which also is down.

“We were hoping to bid it out for construction very soon, but then COVID-19 and all that, so that timeline is kind of in the air,” said West Plains Administrator Tom Stehn, a former state highway engineer. “It was a high priority for us.”

Though ambulances are running as usual and detours are well-marked for visitors, “obviously that direct interchange would be nice,” said Daniel Marshall, chief clinical officer for the South Howell County Ambulance District.

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The city of Bend, Oregon, the nation’s seventh-fastest growing metropolitan area over the past decade, pulled a $190 million transportation bond off the May ballot. Supporters had concerns about pushing a property tax hike for roads, sidewalks and bike lanes while local businesses are suffering financially and many residents are without work.

“They’re going to show up on voters’ day and just glance and think, `I’m not raising my taxes right now, no way!“’ said Mike Riley, co-chairman of the Go Bend 2020 Coalition that supported the measure. “We’re going to come back to voters, but now just felt like the wrong time.”

Most states have classified road construction as essential work that can continue despite orders shutting down certain businesses. But some states have not.

Washington, site of the first coronavirus outbreak in the U.S., suspended work on 92 of its 100 active highway projects as a result of a stay-at-home order for most workers. The halted projects include major ones in Seattle and Spokane, as well as improvements to an Interstate 90 pass through an avalanche-prone area of the Cascade Mountains.

Vermont’s entire $200 million road construction plan for 2020 is on hold, save for a $6 million emergency repair where a storm washed out part of the foundation on Interstate 89.

The longer the delay, the greater the likelihood that some projects might not get finished this year.

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“Every project is sort of at risk of running out of quality weather days to complete the work,” said Jeremy Reed, construction engineer for the state’s transportation agency.

Pennsylvania originally halted all road construction work. But it has since allowed work to proceed on 61 critical projects. About 800 road and bridge projects, at $7 billion, remain on hold.

By contrast, some states have taken advantage of a lull in traffic to speed up transportation projects. Construction crews have been able to shut down highway lanes during prime hours without causing major traffic backups.

Florida announced that it is accelerating work schedules by several weeks on about $2 billion worth of bridge and road projects.

In Maryland, a westbound lane of the Chesapeake Bay Bridge near Annapolis recently re-opened to vehicles following repairs. The $27 million project was completed well ahead of schedule, partly because of light traffic amid the coronavirus pandemic.

The declining traffic volumes have been especially large in some of the nation’s most famously congested metropolitan areas, such as the San Francisco Bay area.

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Business leaders in the region had hoped to put a 1 cent sales tax on the November ballot that could raise $100 billion over 40 years for public transit and transportation projects in a nine-county region. But the coronavirus outbreak interrupted work on state legislation needed to place the measure on the ballot.

It now could be 2022, or even 2024, before supporters can make another push for a public vote on the measure, said John Grubb, chief operating officer of the Bay Area Council, a business-backed policy advocacy group.

“If we’re in a poor economy, which it looks like we’re going to be in, that would have been an awful lot of stimulus and an awful lot of job creation,” he said.

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