WSDOT built a roundabout at I-5 and Slater 10 years ago. Why are they building again?
Construction is underway on an $8 million project to double the size of a roundabout in a fast-growing area between Bellingham and Ferndale.
A roundabout west of the Slater Road crossing over I-5 is being expanded from one lane to two, the Washington State Department of Transportation’s Madison Sehlke told The Bellingham Herald in a phone interview.
A “compact” roundabout between I-5 and Rural Avenue was meant to be a short-term solution when it was built in 2014, Sehlke said.
“They were always looking at it as a temporary cost-effective fix for this intersection. So far, they have successfully and safely kept traffic moving,” she said.
The new multi-lane roundabout will allow traffic to keep moving on Slater and ease congestion on the exit ramp to Slater from southbound I-5.
Nearly 15,000 cars and trucks use Slater near Rural Avenue every day, according to a 2019 survey fro the Whatcom Council of Governments.
Sehlke said the area is expected to keep growing and there are a half-dozen or more traffic projects planned there in the next decade. There are also small roundabouts on the east side of the freeway for the northbound I-5 ramps and at Pacific Highway.
“The big picture is that intersection is going to change,” Sehlke said.
Work on the new Slater roundabout started last month and will continue into late October or early November, Sehlke said. There will be occasional lane and ramp closures as work continues, she said.
“With the traffic increases predicted for this area, roundabouts have shown to be the safest and most efficient way to move traffic,” Sehlke told The Herald in an email.
“It kind of ‘softens’ traffic,” she said.
▪ The Federal Highway Administration found that roundabouts can increase traffic capacity by 30% to 50% over traditional intersections
▪ Modern roundabouts are designed to accommodate cars and trucks of all sizes, including emergency vehicles, buses, and truck and trailer combinations.
▪ In addition to central island, modern roundabouts also have triangular “splitter” islands to slow and direct traffic.
“The islands also provide a refuge for pedestrians,” Sehlke said. “This means pedestrians can choose to cross one direction of traffic at a time and have a safe place to wait before crossing another direction of traffic. This is a benefit to Slater Road as there are upcoming pedestrian improvements in the works.”
This story was originally published August 10, 2024 at 5:00 AM.
