Roundabouts coming to I-5, Slater Road interchange area

Whatcom County, WA:   If you’ve ever been caught waiting a while to turn at Slater Road and I-5 or Pacific Highway near Bellingham, a solution is coming. This week the Whatcom County Council approved a plan for WSDOT to build three compact roundabouts in that area. They’ll be located at the northbound and southbound I-5 ramps at Slater Road and at Pacific Highway and Slater Road. Work will begin September and take only a couple of weeks to complete.

We looked at a number of options for these intersections, including making each a four-way stop, installing traffic signals or adding full roundabouts. Four-way stops would create even bigger traffic back-ups, especially at peak hours. Signals or full roundabouts cost about $1.5 to $2.5 million each. These compact roundabouts will be built in the existing paved area for about $100,000 apiece.

Compact roundabouts are smaller – about 62 to 67 feet in diameter at these three intersections, compared to up to 120 feet for a full roundabout. Also, the center island of a compact roundabout is three inches tall, while a full roundabout’s center may be six inches or more, with a three-inch truck apron around the edge. The smaller size allows compact roundabouts to be built more quickly with less disruption to traffic.

This information was shared from Washington State Department of Transportation, Whatcom County.