The Washington State Department of Transportation expects a bridge expansion joint repair project to cause lengthy traffic backups and delays in Olympia Washington in mid-September.

The project will take place over the weekends of Sept. 12 and 19 on an expansion joint that spans northbound and southbound traffic on Interstate 5. It is also expected to affect U.S. 101 traffic approaching Interstate 5.

North and southbound sides of Interstate 5 will be reduced to two lanes in each direction during daytime hours over the two weekends and will be reduced to a single lane at night. WSDOT predicts backups that will be miles long, especially on southbound Interstate 5.

No detours will be provided to motorists and WSDOT says that other state highways that detour around the work are inconvenient and lengthy.

Interstate 5 is the major route for freight haulers on the west coast and the Washington State Department of Transportation is asking truckers to defer trips over those two weekends or take alternate routes.

For more information go to the Washington State DOT website.