SEATTLE -- Rain delayed their paving work, but crews finished replacing 34 worn-out expansion joints on Interstate 5 in Seattle on Monday.

The state Department of Transportation says that's a big step in the project to refurbish a mile-long stretch of the northbound lanes just south of downtown.

Now the contractor, Concrete Barrier Inc., will focus attention on paving. It needs a few hours of dry weather to do that, but also has a giant, trailer-mounted blow dryer at its disposal to help dry the pavement.

Steady rain complicated matters Monday as the freeway was reduced to just two open lanes.

It took drivers about half an hour to make it through backups in the construction zone, which stretches between the West Seattle Bridge and Interstate 90. Alternate routes were also heavy.

Wednesday morning saw similar traffic volumes, with traffic on northbound I-5 backing up to about the Michigan Street exit.

The DOT says it is still on track to finish the project by Saturday - five days ahead of schedule. Just two northbound lanes will remain open until the project is completed.

Crews plan to pave for 18 hours a day for the next three days. They're using a machine that can pave about 150 feet of roadway each hour.

Transportation officials continued to ask drivers to use alternative routes or mass transit to lessen congestion in the work zone.