HOUSTON, Texas (CNN) -- Hundreds of thousands of would-be evacuees faced long lines of traffic and short supplies of gasoline on Friday as they crept away from the Texas coast to escape Hurricane Rita's fury.
Highways leading out of Houston and other coastal cities were lined with cars, vans and 18-wheelers that had pulled over -- many had broken down, run out of gas or their drivers were simply too tired to go on.
On gridlocked Interstate 45 near Dallas, a bus carrying Hurricane Rita evacuees caught fire, killing one and injuring others, according to a witness.
The Category 4 storm was expected to reach the coast late Friday or early Saturday, the National Hurricane Center said. (Watch Texas residents cope with gridlock on the roads and in the sky -- 2:18)
If motorists are still stuck in their cars when the storm hits, they could be in a dangerous situation, Ed Rappaport, the hurricane center's deputy director, said Friday.
"The hope, of course, is that this storm is off to the right as far as they're concerned," he said of Houston drivers. But "that just moves the problem to another community."
Rappaport said that Rita's current track would bring it ashore north of the Houston area, but he said that could change at any time.
At 8 a.m. ET, Rita was centered about 260 miles (418 kilometers) southeast of Galveston, Texas, and 220 miles (354 kilometers) south-southeast of Cameron, Louisiana. It was moving to the northwest at 9 mph (14 kph).
The storm had maximum sustained winds of 140 mph (225 kph).
Late Thursday, Houston Mayor Bill White said that except for people who live in high-risk areas near the water, those still at home should stay put, especially given the traffic conditions and an unanticipated fuel shortage.
"Now is not the time to get into your car to start the evacuation," White said. "We will get people who are stranded on the roadside off the roadside before the storm comes in," he said. "That is our commitment."
Gas stations along some of the major roads out of Houston and Beaumont, to the east, were running low on gas, said Steven McCraw, director of the governor's division of emergency management.
"We've traveled approximately 20 miles in nine hours with two sheepdogs," said Nick Nichols, who headed out of Houston at 6 a.m. on Thursday. "The orders were to evacuate from Houston, and ... we're out here on a parking lot."
The two National Guard tanker trucks, each carrying 5,000 gallons of gas, were sent at daybreak Friday to help thousands of people who had run low on gas while trying to evacuate, said Chief Master Sgt. Gonda Moncada, spokeswoman for the national guard.
The trucks were sent out to help motorists on Interstates 10, 45, 59 and 290, Moncada said.
Because nozzles on the military vehicles were too large to provide fuel to civilian vehicles, 1-inch nozzles had to be flown in, she said.
Moncada said that 10,000 gallons of gas might not be enough to help everyone who needs it.
Some Houston residents tried various routes out of the city only to become so flustered they returned home and thought about riding out the storm. Other Texans on gridlocked roads pushed their cars to help conserve fuel.
Officials said traffic would be allowed to drive north for 100 miles in the southbound lanes of Interstate 45, the major route to Dallas.
With the hurricane generating winds of tropical storm force extending 205 miles (335 kilometers) from the center, some areas in Louisiana already were feeling Rita's outer bands. (Watch a report on the science behind monster storms -- 3:50)
A hurricane warning was in effect from Port O'Connor, Texas, to Morgan City, Louisiana, meaning hurricane conditions such as sustained winds of at least 74 mph (118 kph) are possible within 24 hours.
New Orleans, still recovering from Hurricane Katrina, was under a tropical storm warning, meaning sustained winds of at least 39 mph (62 kph) are expected within the next 24 hours.
