Nagin, who drew popular scorn for failing to help the city's poorest residents get out before Katrina, said he was pleased with yesterday's process.
"This is night and day from Katrina," Nagin said in an interview. "Katrina was some hard-earned experience. Now we're putting that experience to work."
There was only one glitch in yesterday's process: An Internet-based registration system for the evacuees, designed to synchronize their identification information to barcodes on their wristbands, was overwhelmed and quickly crashed.
But officials armed with scanners and laptops rapidly improvised around that problem by boarding the buses and trains with the evacuees to record their information en route and then upload it wirelessly from the road.
Much of the city, its population already depleted since Katrina, looked empty yesterday, suggesting that most residents were heeding official warnings and getting out well in advance of the storm.
Many evacuees said they knew that the city's network of levees is still only partially repaired - and even if the U.S. Army Corps of Engineers completes the work on schedule in 2011, the system will still not be able to withstand a Category 4 or 5 hurricane.
In the city's Lower Ninth Ward, which was wiped out when Katrina smashed a levee along the Industrial Canal, a handful of families who had rebuilt their homes could be seen loading up their cars with suitcases and coolers, on their way out.
Despite the official assurances that their property would be protected, many New Orleans business owners stung by the lawless aftermath of Katrina were taking no chances. ATMs along Canal Street sported fresh signs saying they would remain empty until after the storm passes. Workers who had been using plywood sheets to rebuild houses and businesses abruptly shifted their efforts to boarding up windows and doors as protection against looters.
"It's not the wind or the water I'm worried about," said Tyler Malejko as he nailed thick wooden planks to the window frames of his wife's upscale kitchen cabinetry store in the Mid-City neighborhood. "The police couldn't protect anybody the last time, and I have no confidence things will be any different now."
The Associated Press contributed to this article.
Impact U.S. grants after Katrina have had little effect. PG 22
