The Connecticut Department of Transportation is warning drivers to avoid Interstate 95 through Westport this weekend.

Starting Friday night, all northbound lanes will be shut down at Exit 17 for a major bridge replacement. All traffic will have to squeeze into the southbound lanes headed toward Norwalk, with all lanes re-opening by 6 a.m. on Monday.

"Use alternate transportation methods, like the Parkway or I-84," said Michael Rosenblatt, DOT's project manager. "Other projects will not be running that weekend."

In just one weekend, Rosenblatt's team will tear down the existing bridge over Saugatuck Avenue in Westport and – literally – slide a new one into place.

It's a relatively new type of bridge replacement called a "lateral slide." For the past six months, crews have been building the new bridge right next to the interstate. They plan to use a track to shift the bridge into place, about 3 feet per hour.

A lateral slide costs a little more, but saves a lot of time – and traffic – over the old way.

"The project would have to be done in stages," said Rosenblatt. "So you'd essentially have a three-lane highway down to two lanes for a minimum duration of six to 12 months."

The bridge replacement is part of the larger I-95 Norwalk Westport Project, which is set to conclude in about a year. In addition to bridge repairs, the project is also improving drainage to stop major flooding around Exit 16 in East Norwalk.

Expect to see a lot more roadwork across the state, thanks to $5 billion in infrastructure money from Washington.

"We're just finishing up Rochambeau in Newtown and the Mixmaster in Waterbury," said DOT spokesperson Josh Morgan. "We're going to get going on the Route 15/I-91/691 interchange."

Weather could delay the project by a week. The weekend forecast calls for another round of heavy rain, which could pose a problem for paving and painting stripes on the new bridge. Morgan said DOT will make the final call on Friday morning.

After that, drivers will get to do this all over again in two weeks. Crews are set to replace the southbound bridge during the first weekend in November.