SEQUIM — The commuting delays on U.S. Highway 101 east of Sequim are expected to be over after Friday.

The week-long one-way, alternating traffic near Gardiner began Sunday and is scheduled to run through Friday evening.

The speed limit in the area between Knapp Road and Diamond Point Road has been reduced to 25 mph from 55 mph through the area, as the state Department of Transportation (DOT) replaces a culvert.

Travelers are experiencing delays up to 90 minutes.

The lane closure allows construction workers to remove a small culvert under the roadway and replace it with a larger concrete box culvert, state transportation officials said. The work also allows fish to move more freely through the area during migration, which helps protect and restore salmon runs, the agency said.

A timed traffic signal alternated traffic each direction of traffic through the area. Bicyclists follow a detour on the nearby Discovery Trail.

DOT offers the following tips for drivers:

• Add up to 90 minutes of extra travel time to help prevent delays.

• Consider postponing discretionary trips.

• Travel early in the morning or later at night.

• Carpool, use transit or telework if possible.

With one lane closed, drivers are seeing an increase in congestion approaching both sides of the work zone. DOT is encouraging travelers to not use county roads as a bypass as it will create congestion on routes needed for first responders and local residents.