The Online Voice of the Bicycle Alliance of Washington

Friday, July 9, 2010

Rumbling about rumble strips pays off

As a bicycle advocate, I’ll take every victory I can get and one just crossed my desk. But first the back story…

In May, my phone rang with this admonishment, “Rumble strips are being cut into the shoulder of SR 525 on Whidbey Island right now! What’s going on and what are you doing about it?”

Yikes, and I was just talking with Adventure Cycling Association’s National Bicycle Routes staff about Highway 20 as a Washington treasure. I hopped on my trusty bicycle, loaded up my panniers and headed south on Whidbey Island with my husband Andy. We rode for the next two days crying in frustration and anger to see rumble strips carved into the shoulders of a premier cycling route.

Upon returning home, I armed myself with this picture and headed to Olympia confident but very unhappy that rumbles had been cut seemingly without regard to Washington State Department of Transportation (WSDOT) guidelines.

I met with Transportation Secretary Paula Hammond and two of her staff: the WSDOT Bicycle and Pedestrian Coordinator and the person from WSDOT’s Design Office responsible for writing the Design Manual. I explained what had happened and showed them the photo. I asked that the Design Manual be amended and updated, and I asked for an evaluation of the rumble strip installation on Whidbey Island. That was in June.

Now, in July, some good news! An evaluation by WSDOT headquarters staff validated my appraisal that rumble strips on SR 525 were incorrectly installed along guardrails and other locations, and will be paved over later this summer--SUCCESS! Rumbles on SR 20 were also incorrectly applied and will be paved over next summer--PARTIAL SUCCESS! Changes were made to the Design Manual regarding outreach--MINOR CREDIT! More work needed.

Is it a victory that I rode the length of Whidbey Island in the rain with my crabby husband to tell WSDOT that they had done something incorrect and unnecessary? That rumbles affect bicycle safety and interstate tourism? I’ll claim the victory when rumbles are used sparingly for the safety of all roadway users. Watch for action alerts as the Bicycle Alliance plans to act proactively to stop this type of installation.


What’s a rumble strip and why should I care? 

If you ride on city streets or county roads, chances are you won’t ride across rumble strips. However, anyone out riding the highways and byways of Washington for recreation, health and happiness should care because a safety feature for motorists can create a serious safety hazard for cyclists.

To paraphrase the US Department of Transportation a shoulder rumble strip is a “longitudinal design feature" which is a series of indented cuts in pavement intended to alert inattentive drivers through vibration and sound that their vehicles have left the travel lane. For more info, check Federal Highways Administration's Rumble Strips FAQ.


  1. How can we use your success in our area? I believe we have a similar situation in the Hwy 2 corridor near Leavenworth.

  2. Good catch and thank you for your hard work - these details dont matter much to drivers, but they are everything to cyclists. Re-programming the DOT to consider a growing segment of road users is really critical work & you have our heartfelt thanks!

  3. I think you need to check your facts (crabby husband). What, Andy can be a crab? Can't imagine!

  4. I have mixed feelings regarding rumble strips. If they are used on major highways, I believe they can actually benefit cyclists, as they warn of approaching vehicles which may be swerving into or near them. I had to ride a long stretch of I-70 in Utah once, and I felt much safer because of them. They acted like a barrier between the fast moving semis and the slow moving us...

  5. WSDOT staff follow the guidelines in the department's design manual, which states. . ."Ensure that at least 4 feet of useable shoulder remains between the rumble strip and the outside edge of shoulder. If guardrail or barrier is present, increase the dimension to 5 feet of useable shoulder." The problem is that if the rumble strip is 14+ inches wide and placed anywhere from 6-12 inches to the fog line that in order to comply with the design standard there needs to be a minimum of six feet of shoulder to the right of the fog line in the first place. If our learned friends at WSDOT would this fact - THERE MUST BE A MINIMUM OF SIX FEET OF SHOULDER (seven feet when there is a guardrail) - as the standard, contractors who carry out the work would be more inclined to get it right. There are many roads that have 3-5 feet of shoulder that should never have milled rumble strips installed, however with the confusing guideline published in the department's design manual, they are more likely to assume that such shoulders should get rumble strips. Invariably, WSDOT managers provide poor oversight, the Bicycle and Pedestrian Program Manager never seems to be effectively involved in these decisions, despite requirements to the contrary, and the contractor gaily goes about grinding in the rumble strips. The record for getting it wrong is about the same for getting it right, which is hardly an endorsement of the department's procedures and design guidelines. With the use of GPS, the department could survey a road in advance and provide coordinates of those sections that do not meet the minimum six feet/seven feet existing shoulder standard, then provide that information to the contractor and require that as part of the contract, on penalty of getting it wrong. It's all about communicating clearly - the current guideline fail miserably to do so and will continue to result in errors (who pays for those, by the way?) Rocket science it is not.

  6. If anyone has driven or rode HWY 20 past Sedro Wooley to Marblemount, the rumble strips are only about 4 inches wide and are cut into the fog line. This does not take away from the shoulder for riding at all and should be the standard for this type of safety feature. The rumble strips on Whidbey are dangerous for bikers and were not installed with much regard to quality standards or clean up afterwards. The pebbles and resultant asphalt debris has punctured my tires on my road bike more than once since the strips have been put in. I avoid use of HWY 20/525 on Whidbey as much as possible nowadays.