Rumble strips to be installed on state Route 900
August 3, 2010
By Paige Collins
Rumble strips are to be installed on state Route 900 from western Issaquah to Tukwila on Aug. 5, according to Mike Murphy, a state Department of Transportation spokesman.
One lane will be alternated around the work zone from 8 p.m. – 5 a.m.
Both shoulder and centerline rumble strips, as well as some patches of guardrail, will be installed from Issaquah near Talus to about 148th Avenue Southeast in Renton.
Rumble strips are grooves in the pavement along the shoulder or centerline that when driven over cause the car to vibrate and alert a driver that he or she is leaving the roadway.
“Typically, they are installed on fairly rural highways where there is no divider or if there is a risk of cars leaving the roadway. State Route 900 fits that,” Murphy said.
The number of traffic accidents involving off-the-road or over-the-centerline collisions demonstrates a need on the road as well.
In the past five years, in a five-mile stretch of road, there were 71 off-the-road collisions and 25 over-the-centerline collisions, based on accident report data from the DOT. The two fatalities in the five-year period were caused by one head-on collision and one vehicle hitting a guardrail.
DOT research has shown up to a 40-percent reduction in run-off-road accidents when rumble strips were present, according to the organization website. Officials hope to see a similar increase in safety on state Route 900 with the installation, Murphy said.
Rumble strips, while they bring drivers’ attention back to the road, can bring about problems for the cycling community. They can leave inadequate shoulder space and rough patches of road that are unsuitable for cyclists, said David Hiller, advocacy director for the Cascade Bicycle Club.
“Rumble strips are a solution that isn’t always appropriate for the conditions,” he said.
Hiller elaborated that they are most effective in road-trance crashes, in which the driver falls asleep or loses focus, but that not all off-the-road collisions have that cause.
Murphy recognized the cycling perspective when discussing the plan, and ensured that if the shoulder width is narrower than four feet wide, no rumble strips will be installed.
“We did coordinate with the bike community to make sure that we did it in such a way that they are accommodated,” Murphy said.
The transportation agency did contact the Cascade Bicycle Club, Hiller reported, and he is “not all that concerned about what the DOT is doing.”
Paige Collins: 392-6434 or firstname.lastname@example.org. Comment at www.issaquahpress.com.