US drivers began longer commutes on Monday after an elevated section of the Interstate 95 road collapsed in Philadelphia following a fire on a fuel tanker truck.

Sunday’s fire closed a heavily-travelled segment of the US East Coast’s main north-south highway indefinitely.

Newscasts warned of traffic nightmares and gave advice on diversions, urging drivers to take more time to travel.

“This is really going to have a ripple effect throughout the region,” AAA spokesperson Jana Tidwell said, advising people to avoid peak travel times.

Ms Tidwell also anticipated that drivers will incur additional costs – “more gasoline, more wear and tear on their cars, additional tolls, in terms of leaving Pennsylvania into New Jersey and then back into Pennsylvania”.

The Southeastern Pennsylvania Transportation Authority said it was operating three extra morning and late afternoon trains on its Trenton, New Jersey, line, and adding capacity to regularly scheduled lines during peak hours “to help support the city and region’s travel needs” following the collapse.

Transportation officials warned of extensive delays and street closures and urged drivers to avoid the area in the city’s north-east corner.

Officials said the tanker contained a petrol product that may have been hundreds of gallons offuel. The fire took about an hour to get under control.

The northbound lanes of I-95 were gone and the southbound lanes were “compromised” by heat from the fire, said Derek Bowmer, battalion chief of the Philadelphia Fire Department. Run-off from the fire or perhaps broken gas lines caused explosions underground, he added.

Some kind of crash happened on a ramp underneath northbound I-95 around 6.15am on Sunday (11.15am BST), said state Transportation Department spokesman Brad Rudolph, and the northbound section above the fire collapsed quickly. A massive concrete slab fell from I-95 onto the road below.

Governor Josh Shapiro said his flight over the area showed “just remarkable devastation”.

“I found myself thanking the Lord that no motorists who were on I-95 were injured or died,” he said.

The collapsed section of I-95 was part of a 212 million dollar (£168 million) reconstruction project that wrapped up four years ago, Mr Rudolph said.

Motorists were sent on a 43-mile diversion on Sunday, which was going “better than it would do on a weekday”, Mr Rudolph said.

The fact that the collapse happened on a Sunday helped ease congestion.

Pennsylvania transportation secretary Michael Carroll said the I-95 segment carries roughly 160,000 vehicles per day and is likely the busiest interstate route in Pennsylvania.