No doubt about it: The word got out.

But only time will tell whether Saturday's light traffic through an Interstate 5 construction zone — estimated at 40 percent of a normal Saturday — indicates motorists will be spared the nightmarish scenarios the 19-day project could create.

"We're still waiting to see what's going to happen Monday during the commute," said Lauren Penning, a spokeswoman for the state Department of Transportation. The one-mile stretch of freeway approaching downtown Seattle — on which some of the five northbound lanes are being closed — carries 126,000 vehicles on a typical weekday.

Saturday evening, transportation officials were reporting only sporadic periods of congestion in the construction area, with speeds varying from 25 mph to the posted 45 mph limit.

People who normally drive through the area are still urged to consider different routes or other modes of transportation, including buses and carpools.

But at least one alternate route, Interstate 405, was more congested Saturday afternoon than the I-5 section under construction, prompting state officials to caution, temporarily at least, that northbound 405 was not a good alternative.

The closure, which began Friday night, is scheduled to continue through early Aug. 30. Workers are resurfacing the roadway and replacing worn-out expansion joints between Spokane Street and Interstate 90.

Crews were keeping an eye on the weather forecast, which included the possibility of showers overnight and today.

"They can't pave in the rain, that's the bottom line," Penning said, "but we do have some dryers we can bring in to dry out the pavement quickly once the rain stops." The large, cylindrical dryers are mounted on trailers and pulled by trucks.

Work is proceeding around the clock, and the contractor, Concrete Barrier of Mukilteo, has an incentive to complete the job as quickly as possible. Penning said the company, which has a $12 million contract, can earn an additional $100,000 for each day the project is completed early, up to nine days, but faces a $100,000-a-day penalty if the work runs late.

Although the job was timed to minimize conflicts with major events, nine Mariners home games, starting with a 7:05 p.m. game Monday, will add to the congestion.

West Seattle residents are feeling particularly affected by the freeway project. Over the weekend, the ramp from the West Seattle Bridge to northbound I-5 is closed, and when it is reopened Monday, it will send motorists into the construction zone.

"I'm totally petrified," resident Lorie Bennett said.

Bennett and her husband, Chris, will try out the water taxi connecting West Seattle with downtown Monday morning. "I'm pregnant and I have two toddlers and I don't know how crowded it's going to be," she said.

The Bennetts' jobs and day-care center are located downtown. On Saturday, the family decided to stay near home.

They took the kids for a haircut and to the beach. Usually, they venture out on the weekends and take the kids to a museum or the Pacific Science Center.

In preparation for the closure, green signs were posted at bus stops along Admiral Way, advertising shuttle service to the water-taxi dock at Seacrest Marina.

A few blocks from Alki Beach, a group of neighbors held a garage sale. They'll wait until Monday to judge how bad the traffic will get. "Nobody's happy about it," said Stephany Angelacos. "There's nothing I can do about it."

Angelacos said official suggestions — such as taking a vacation during the closure — were not realistic. "People are not going to hunker down for three weeks," she said.

Neighbor Jennifer Engel said she plans to drive to her job in Fremont despite the freeway work. The water taxi, she said, would only get her downtown, and from there a bus would take too long and a cab would be too expensive.

The first day of roadwork didn't prevent people from getting to West Seattle, judging from the crowd at Alki Beach, which included the familiar mix of parents, kids and dogs on leashes, along with a wedding party posing for photos, scuba divers and contestants in a bench-press competition.

Carol Bailey of Bellevue, walking her dog, knew about the construction but said she didn't mind being in traffic a little longer to get to the beach she visits about twice a year.

Bailey works in Seattle and takes the bus from Bellevue and is not planning any change in her commute. It'll "just stay the way it is and hope for the best," she said.

Jack Broom: 206-464-2222 or jbroom@seattletimes.com