After a weekend of hours-long traffic jams, construction crews near the Woodrow Wilson Bridge finished realigning a section of the Capital Beltway last night in time for this morning's rush hour.

All lanes of the highway and associated ramps were reopened by 9:57 p.m., said John Undeland, the chief spokesman for the bridge project.

He said the backups that had accumulated during the lane closures were dissipating rapidly. Motorists heading to work over the bridge this morning will face nothing out of the ordinary, he said.

The paving was finished well ahead of time despite the weekend's oppressive heat and humidity, which made it more difficult to lay tons of steaming-hot asphalt.

The restrictions that had narrowed the Beltway's four-lane inner loop to a single lane were lifted. The ramps connecting the inner loop to Route 1 north and south, and the Interstate 295 ramp to the inner loop, were reopened as well.

"It's back to normal on Monday morning," Undeland said.

The end of the weekend's work, part of the 11-year, $2.43 billion Wilson Bridge replacement, marks a significant milestone for the project. Nothing else on the schedule should affect traffic as much, Undeland said.

"Closing down the Beltway to one lane for a weekend -- we don't plan to do that again," he said. "We don't plan to do anything of this magnitude in terms of traffic impact."

Yesterday's backups at the Potomac River crossing were not as bad as Saturday's, when traffic stretched for six miles east of the bridge into Maryland. But with the inner loop reduced to one lane between I-295 in Maryland and Route 1 in Virginia, it was by no means easy-going.

The wait to get across the Potomac grew from about 30 minutes at 11 a.m. to more than an hour by midafternoon, according to Maryland State Police. By 4 p.m., traffic was backed up about four miles, police said.

Undeland attributed the slightly better flow to there being fewer vehicles. After Saturday's tie-ups, which lasted three hours at times, drivers might have gotten the message to stay away, he said.

There also was less rubbernecking, he said. On Saturday, motorists passing through the construction zone slowed to 25 mph or less to see what was going on.

"It took so long for people to get through," Undeland said. "It was death by a thousand cuts. There was a ripple effect. One stops and looks, and then another and another."

But yesterday, many motorists drove by at speeds approaching 45 mph, he said, and traffic moved more freely.

The paving began about 8 p.m. Friday, and officials thought it would take until 5 a.m. today. The heat was an impediment. Pavement must be laid a few inches at a time, and crews had to wait for each layer's temperature to drop from 300 degrees to less than 150 before applying another. Crews sprayed cooling water from tanker trucks on the fresh pavement to speed the process.

Leading up to the weekend, transportation officials warned motorists of what they said could be the project's worst traffic tie-ups. In a region with some of the nation's worst traffic, officials feared the snarls would set records. Transportation officials broadcast radio ads along the East Coast and sent e-mails to truckers and other regular drivers, urging them to use alternate routes.

Undeland said last night that he believed many motorists got the message. If they had not, he said, backups would have been far worse.

Crews shifted a half-mile section of the inner loop south at South Washington Street in Alexandria, matching a shift of the outer loop last month.

The realignments were necessary to build an overpass at South Washington Street and are part of the project to replace the Wilson Bridge. The new bridge will have two six-lane spans, the first of which is scheduled to open in the spring.

Staff writer Martin Weil contributed to this report.