Boyer Chew, working the graveyard shift, had just loaded up his tanker in Baltimore and was cruising down Interstate 95 before dawn yesterday to deliver the gasoline to filling stations. In Prince George's County, he happened to glance in the rearview mirror: Fire was shooting out of his right rear tire.

He was sitting on 8,600 gallons of gasoline. A bomb.

Fighting the impulse to just leap out of the cab and flee, Chew eased the truck over to the side. Then he jumped for all he was worth and started running.

In seconds, the truck exploded into a fireball.

Flames shot into the sky, scorching pavement and forcing hundreds of commuters and travelers to evacuate their cars in the frosty morning of one of the busiest travel days of the year.

The blaze burned for two hours and was so intense that a 125-foot stretch of the two right lanes and shoulder were rendered unusable. All lanes of I-95 in both directions were shut down for an hour at 5 a.m., with the southbound lanes closed for about three hours. The highway did not completely reopen until 2 p.m.

When it was all over, the truck was hauled away as a heap of charred metal. But no one was dead, no one was injured and a lot of people were shaking their heads at what might have been.

When Chew, a driver for Maryland-based Ocean Petroleum, abandoned his truck, he left his cell phone inside. So he flagged down a family from New Jersey who were driving by, and they called 911.

"That man from New Jersey, I don't know who he was, but he comforted me," said Chew, a former boxer who has driven a truck for 15 years.

Thanks to shrewd moves by Chew, his life and countless others were saved. And nine hours after the tanker exploded, the road was cleared, scraped, asphalted and back open for holiday travelers.

Before the road reopened, traffic was backed up three miles both ways on I-95 just north of where it splits with the Inner Loop of the Beltway, not much worse than what happens on Washington area roads nearly every day of the year.

That was partly because of a lighter-than-usual rush hour at the beginning of the holiday and because traffic alerts raced up and down the eastern seaboard within an hour of the incident.

Still, hundreds were slowed down.

John and Sheila Davis of Darlington, S.C., who were on the way to New Jersey to see relatives, were among hundreds yesterday who found the drive on I-95 rough going after the fire.

"I'm from the South, so I'm not used to that kind of traffic," said Sheila Davis. While she was stuck in the gridlock on the northbound lanes she called her sister, who lives in the region. "I said, 'Is this how it is all the time? Where are people going?' "

But John Townsend, spokesman for AAA Mid-Atlantic, who was on the scene throughout the day, found the fast cleanup "amazing."

When drivers "got to the site, there were no telltale signs of anything -- except charred trees on the side of the road," he said.

On a day when all construction projects had been halted to make way for holiday traffic, highway workers launched a feverish scramble to get personnel and equipment to the site to make a quick fix and allow traffic to flow.

Street sweepers and milling trucks from Beltsville were called into action. An asphalt plant in Rockville was contacted. A road painting crew came from Greenbelt.

The first order of business was to clear the highway of debris, which included chunks of the charred truck as well as pieces of pavement. That was finished shortly before 11 a.m.

Then came the milling trucks, which scraped away the top 1.5 to 2 inches of road. At the same time, trucks with 325-degree asphalt were rolling in, and giant rollers used to smooth it down were ready to go.

In little more than an hour the millers had completed their part of the mission, clearing the way for the asphalt. Within another hour, workers had repaved the highway with 66 tons of asphalt, flattened it, verified that the job had been done right and restriped it.

About 30 minutes later, enough time for the asphalt to cool and to remove orange cones, and about nine hours after the incident started, a newly paved and newly striped highway opened for use.

By 6 a.m., signs from Virginia to Maine alerted drivers to the delays. By 7 a.m., local television crews were on site, and the enormous fire was broadcast on national network news shows.

"The one thing they were saying about Washington is not what the president was doing, not what was happening at the Pentagon, but what was going on at this spot on I-95 because it's a major corridor not just for the Washington area but up and down the East Coast," Townsend said.

Mark Brady of the Prince George's County Fire and Emergency Medical Services Department said the cause of the tanker fire, whose tall flames spread onto the median and into nearby woods, was unknown. But he said a likely cause was the truck's brakes locking up, overheating and igniting the rubber tire.

Yesterday's weather proved to be rather serendipitous for highway workers. By the time the asphalt was ready to be poured, the temperature climbed higher than 45 degrees, the number needed to lay a permanent layer of pavement.

If the temperature was lower than 45 degrees, as is expected tomorrow and through the weekend, the asphalt would not have held as well, and highway workers would have needed to go back and redo the repaving. Also, the wintertime temperatures helped the asphalt cool quickly.

On a normal day, about 190,000 cars travel the site of the explosion, which is a four-lane stretch of southbound I-95 at Cherry Hill Road, said Maryland State Highway Administration spokesman David Buck. The day before Thanksgiving, that could be up to 250,000 or 300,000 vehicles, Townsend said.

Highway officials said it was fortunate that no one was injured and that the incident occurred before the morning rush began in earnest.

"If it happened at 7 a.m. it would have been much worse," Buck said.

Chew's view of the accident occurring at an auspicious hour: "You really don't know when it's your time."

His wife, Cheryl Chew, said she became concerned yesterday morning at 5:20 when she did not get her regular wake-up call from her husband at their home in Odenton. He calls every morning to make sure she's awake in time to get to her accounting job in the District.

She turned on the TV news and watched in horror as a tanker was engulfed in flames. She was standing mesmerized in front of her TV when the phone finally rang.

"He called and said that he was okay," she said.

After the harrowing experience, the Chews, who are newlyweds, decided to scrap their Thanksgiving plans to go to Harrisburg, Pa., and spend the weekend by themselves celebrating the holiday.

"I am going to cook," Cheryl Chew said.

Staff writers Steven Ginsberg, Joshua Partlow and William Wan and staff researcher Bobbye Pratt contributed to this report.

The scene of the explosion. The truck carried 8,600 gallons of gasoline.