Rumbling to a slower speed

TYEE – Drivers headed west toward the Tyee curve may now receive a jolt as they approach on Highway 138 West.

That’s precisely the point for three sets of rumble strips cut sideways into the pavement last week to warn drivers as they approach the hairpin curves that have caused numerous accidents over the years.

“Hopefully, it will slow them down and wake them up,” said Darrin Neavoll, who oversees maintenance programs in Douglas, Coos and Curry counties for the Oregon Department of Transportation.

Rumble strips cause vibrations to the vehicle to alert a driver and also produce a noise as the tires travel through the indentations and then back up to regular pavement level.

Two sets of the strips, with about 90 feet between them, are located on the straight stretch of Highway 138 West approaching the curve. A third one was placed closer to the curve.

“The thinking was to give them two quick bursts and then they look up and see the ‘Slow’ sign,” Neavoll said.

Each set consists of 11 grooves 5 1/2 inches long, 10 feet wide and a half-inch deep over a 15-foot section of pavement. Each indention is 18 inches apart.

Plastic reflectors were also installed along the center line at the curve. Several sets of painted white blocks will be added to the pavement in the near future for addtional emphasis on the approach.

The strips were placed only on the westbound lane. There are no plans as of now to place them on the eastbound approach to the curve, ODOT spokesman Jared Castle said.

The angle isn’t as severe for eastbound travelers, and there is a flat spot off that side of the road if a driver enters the curve going too fast. Westbound drivers who can’t maintain their position in the travel lane face crossing into oncoming traffic or hitting the rock wall on the right side.

ODOT looked into the possibility of removing that wall, but Castle said it would cost as estimated $15 million to do so. That wasn’t financially feasible, he said.

Twenty-two miles to the northwest on the highway, additional rumble strips have been installed before the intersection with Highway 38, where after stopping drivers must either turn left to Elkton or right toward Drain.

“This one is more to wake them up to let them know a stop sign is coming up,” Neavoll said. “The other one (at the Tyee curve) is to slow them down.”

Three Sutherlin teen-agers were killed in 2000 when the station wagon in which they were riding went through the stop sign and crashed into a large boulder on the north side of the intersection. The boulder was removed as part of the recent project to replace the bridge leading into Elkton.

Although rumble strips have been used on the sides of Oregon freeways for several years to prevent drowsy motorists from driving off the road, this is the first time in-lane rumble strips have been used in Southern Oregon, ODOT’s Castle said.

Texas has used in-lane rumble strips since 1956. At the time a ceramic bar was anchored to the roadway using an epoxy resin. Other states with long histories of use include New Jersey, Maryland, Nebraska and Illinois, according to a 2005 report by the Texas Transportation Institute at Texas A&M University.

A study that same year by the Center for Human Factors Systems Research and Design at the University of Minnesota found that drivers approaching intersections significantly lowered their vehicle speeds after passing through a section of rumble strips than on roadways not so equipped.

The test was conducted using sleep-deprived commercial truckers. The study’s authors concluded that nonprofessional drivers would also exhibit safer stopping behavior in areas where rumble strips were installed.

• You can reach reporter John Sowell at 957-4209 or by e-mail at jsowell@nrtoday.com.