When a tractor-trailer explosion closed a six-mile portion of an inner-city freeway early Wednesday, the challenge for technicians in Southern Nevada's traffic management facility was obvious: Find other roads to place the 5,000 commuters who travel that stretch of freeway every hour.
That was the task faced by Brian Hoeft, director of the Freeway and Arterial System of Transportation, shortly after a tractor-trailer carrying 9,100 gallons of gasoline overturned and burst into flames on southbound Interstate 15 just north of the Spaghetti Bowl.
"The closer you get to the city, the more impact things have," Hoeft said Wednesday morning as he eyed the live feed of the cleanup mission on a massive monitor.
"I've never seen a truck obliterated. It was one of a kind."
Nevada Highway Patrol investigators have yet to determine what caused the tanker to crash at 3:45 a.m. The driver escaped unharmed, but flames continued to shoot into the air until 5:30 a.m.
After the fire was extinguished and the gasoline cleaned up, Nevada Department of Transportation crews did tests to determine whether the fire was severe enough to weaken the integrity of the freeway. Had they detected extensive damage, three lanes would have been closed until the end of the week while the asphalt was replaced.
Michelle Booth, spokeswoman for the department, said temporary seals were placed in cracks. Permanent repairs will be made throughout next week, causing intermittent lane closures, but nothing to the extent initially feared, she said.
Even so, the state's busiest freeway was closed between the Las Vegas Beltway and Lake Mead Boulevard for nearly 12 hours, creating trying commutes for motorists heading to work and truckers hauling loads to Southern California.
"This is a critical regional route; I-15 is a major arterial for the entire West," Hoeft said. "At the same time, it is a critical local route."
It also created a tough chore for Hoeft's staff at the traffic management center. Digital message signs notified motorists of the closure all along Interstate 15.
Transportation divisions in Arizona and Utah also warned travelers.
That was the easy part.
Motorists quickly found Martin Luther King and Las Vegas boulevards to be the most popular detour routes. Martin Luther King backed up not only because of the drivers departing Interstate 15 but also because of those who were turned back when they hit the freeway from the Beltway.
Traffic signal technicians were sent into the community to monitor traffic. Signals were adjusted to keep traffic moving as smoothly as possible without disrupting the movement on streets that intersect with the major thoroughfares.
Hoeft said Martin Luther King accommodated about double the amount of traffic that it carries on a typical weekday morning. In all, about 40,000 vehicles were rerouted off Interstate 15 south.
"There would have been some (delays), but it was not total gridlock," he said. "We were able to move traffic through at a reasonable speed given the doubling of the volume."
Adding to that challenge is that 10 percent of the 5,000 vehicles that travel that portion of Interstate 15 are tractor-trailers.
Hoeft said his staff realized that with the trucks, only a handful of vehicles would make the left-turn light from Craig Road or Cheyenne Avenue onto Martin Luther King if the trucks had to come to a complete stop.
Traffic signals were adjusted so the lights would turn green before the speed of the trucks coming off the freeway dropped below 20 mph.
"We had green lights popping in front of them at 25 mph so they didn't have to stop and start again," Hoeft said.
The six-mile closure was not because of the gasoline spill but to disperse the motorists searching for alternate routes, Hoeft said.
The accident could have occurred at worse areas of Interstate 15. The portion of freeway between Charleston Boulevard and Sahara Avenue is the busiest in the state, carrying 230,000 vehicles each day.
Hoeft said Wednesday's drill went off without a hitch, partly because his facility is one of the most advanced in the country and partly because the transit division became accustomed to handling detours during the yearlong widening project of Interstate 15 between the Spaghetti Bowl and Craig Road.
"We just grabbed our old plan and dusted it off a bit," he said.
Contact reporter Adrienne Packer at email@example.com or 702-387-2904. Reporter Mike Blasky contributed to this report.