WSDOT proposes solution to safety issues on SR 141

With that said, WSDOT is proposing to install a 6-inch wide edge line shoulder rumble strip “to improve safety of the different types of users of this specific section of this specific route,” Tams wrote.

White Salmon City Administrator Patrick Munyan Jr. hailed the announcement as a positive step forward for all concerned parties.

“We’re glad to see [WSDOT] is moving toward a solution,” Munyan said Tuesday. “And they’re using the more current standard for bicyclists and pedestrians, so that’s good to see, too.”

The section of SR 141 that will be thus improved is about 1.3 miles long (milepost 1.63 to milepost 2.95), with a posted speed limit of 35 miles per hour.

Tams said the need to consider the application of edge line, or shoulder, rumble strips on this section “is not driven by the need to reduce road collisions.”

“The need as noted by the local community is to keep vehicles from encroaching on the shoulder being used by the cyclists and pedestrians,” Tams pointed out.

Since the 1990s, 12-inch wide shoulder rumble strips on the route have delineated the driving surface from the pedestrian surface. The strip was placed outside the fog line and “effectively reduced the available shoulder width for cyclists, which was already narrow, mostly 3 to 4 feet,” Tams noted.

WSDOT engineers told the public at the start of the resurfacing of SR 141 this summer that is would not be replacing those rumble strips. That set off a public outcry from local residents who use the north shoulder, which was designated as part of the 5-mile Loop Trail that surround White Salmon, for walking, running, and cycling. “The local community has stated the [former] rumble strips help the pedestrians understand when a vehicle is encroaching onto the shoulder,” Tams said.

According to Report 641 by the National Cooperative Highway Research Program (NCHRP), on page 3, “On roadways where bicyclists can be expected in or near residential or urban areas, rumble strip patterns should be designed to produce sound levels in the range of 6 to 12 dBA in the passenger compartment...In situations where it is desirable to provide more lateral clearance for bicyclists or for installing shoulder rumble strips on roads with very narrow shoulders, the predictive model indicates that rumble strips can be designed with relatively narrow length, such as 6 inches, and still generate the desired sound level differences of 6 to 12 dBA in the passenger compartment.”

The NCHRP report also notes, on page 13, that, “In some cases the rumble strips may be installed along the edge line of the roadway and may be referred to as edge line rumble strips or rumble strips.”

Moreover, Oregon Department of Transportation specifications state, “Edge line rumble strips are the preferred form of shoulder rumble strips. Placing the edge line overtop of the rumble strip adds conspicuity to the edge line.”