Roundabout construction at Slater Road commences after delays

After several delays, construction for the new roundabouts at the I-5/Slater Road interchange is underway.

Crews from Granite Construction began work on three compact roundabouts on October 29. The county hopes the new roundabouts will help alleviate the potentially dangerous congestion at the interchange, which can see more than 1,600 cars per hour passing through at peak travel times.

The roundabouts will be installed near the northbound and southbound I-5 off-ramps, and near the Pacific Highway intersection. The area has been plagued with traffic problems, with cars often backed up all the way to I-5 and limited sightlines impeding left turns.

Most of the construction will take place at night, between 7 p.m. and 6 a.m. on weekdays. Flaggers will be in place to guide commuters through the work zones.

The county approved the new roundabouts at a regular meeting in mid-August. Construction was slated to begin in September, but the weather caused delays.

Weather remains a major factor for the project, according to Tom Pearce, communications officer for the Washington State Department of Transportation. Road crews need dry conditions to remove the existing traffic islands and begin repaving.

The roundabouts will be built one at a time, and depending on the weather, the project could take up to several weeks to complete.

The compact roundabouts are more cost-effective than full-sized roundabouts. The Slater Road roundabouts will have diameters of 62–67 feet, compared to 120 feet for a full-sized roundabout. The county funded most of the project, which will cost approximately $350,000 to complete.

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