NEW ORLEANS -- Coastal residents jammed freeways and gas stations yesterday as they rushed to get out of the way of Hurricane Katrina.
''Ladies and gentlemen, this is not a test. This is the real deal," said New Orleans's mayor, C. Ray Nagin. ''Board up your homes, make sure you have enough medicine, make sure the car has enough gas. Do all things you normally do for a hurricane, but treat this one differently because it is pointed toward New Orleans."
Katrina was a Category 3 storm with sustained winds of 115 miles per hour yesterday, but the National Hurricane Center said it probably would strengthen over the Gulf of Mexico, where the surface water temperature was as high as 90 degrees -- high-octane fuel for hurricanes. It could become a Category 4 storm with winds of at least 131 miles per hour before it makes landfall early tomorrow, the center said. A hurricane watch extended from Louisiana to the Florida Panhandle, and large-scale evacuations were underway yesterday along the coast.
Katrina could be especially devastating if it strikes New Orleans, because the city sits below sea level and is dependent on levees and pumps. A direct hit could leave the city in several feet of water.
Making matters worse, at least 100,000 people in the city lack the transportation to evacuate. Nagin said the Superdome might be used as a shelter of last resort for people who have no cars, and there would be city bus pickup points around New Orleans.
''I know they're saying 'Get out of town,' but I don't have any way to get out," said Hattie Johns, 74. ''If you don't have no money, you can't go."
The storm formed in the Bahamas and ripped across South Florida earlier in the week before moving into the Gulf of Mexico. The storm was blamed for seven deaths in Florida.
Louisiana and Mississippi made all lanes northbound on interstate highways. Mississippi declared a state of emergency, and Alabama offered assistance to its neighbors. Some motels as far inland as Jackson, Miss., 150 miles north of New Orleans, were already booked up.
''At this juncture, all we can do is pray it doesn't come this way and tear us up," said Jeannette Ruboyianes, owner of Day Dream Inn at Grand Isle, Louisiana's only inhabited barrier island.
Yesterday evening, the eye of the hurricane was about 380 miles southeast of the mouth of the Mississippi River and about 240 miles west of Key West, Fla. It was moving west at nearly 7 miles per hour, the hurricane center said.
''We know that we're going to take the brunt of it," Governor Kathleen Blanco said. ''It does not bode well for southeastern Louisiana."
Some tourists heeded the warnings and moved up their departures, and lines of tourists waited for cabs on New Orleans's Bourbon Street downtown.
''The problem is getting a taxi to the airport," said Brian Katz, a salesman from New York. ''There aren't any."
Others tried but couldn't make it.
''We tried to move it up, but they told us they were all booked up," said Terry Evans of Cleveland, whose flight was scheduled to leave tomorrow morning. ''We may end up sleeping at the airport."
Katrina was a Category 1 storm with 80 mile-per-hour winds when it hit South Florida on Thursday, and rainfall was estimated at up to 20 inches. Risk-modeling companies have said early estimates of insured damage range from $600 million to $2 billion.
Florida utility crews were still working yesterday to restore power to 733,000 customers, down from more than 1 million. Residents waited in lines that stretched for miles to reach state-operated centers distributing free water and ice for those without electricity.