City considers rumble strips on Marine Drive

Ready to rumble?
(Photo: Missouri DOT)

As part of their ongoing High Crash Corridors program, the Portland Bureau of Transportation (PBOT) is considering installing rumble strips on NE Marine Drive.

PBOT bicycle projects staffer Jeff Smith is currently looking for feedback on the plan. Since Marine Drive is a very popular route for weekend riders and racers training for competition, Smith has emailed the idea to local riding groups like the Portland Wheelmen Touring Club and the Oregon Bicycle Racing Association.

PBOT is focusing on Marine Drive (between I-5 and NE 185th) for a safety analysis and improvements because it has a “substantially higher” fatality rate that the citywide norm (17 out of 1000 crashes is fatal, compared to 3 out of 1000 citywide). Adding to the safety issues on the street are high speeds and a lot of truck traffic. According to PBOT data, between NE 33rd and 185th, an average of 82% of all motor vehicles exceed the speed limit (with about 11% exceeding the posted speed by 10 MPH or more).

PBOT statistics show that between 2001 and 2010, there were 398 total reported collisions on Marine Drive and 12 of those involved a fatality. Seven of the collisions involved a person on a bicycle. Below is a chart from PBOT:

One of PBOT’s main concerns is the prevalence of “lane departure” crashes, which is a traffic safety term for when a car leaves the roadway and hits something (like a traffic pole or another vehicle). On NE Marine, those type of crashes are three times higher than the citywide average.

(Source: FHWA)

To combat these departures, PBOT is considering adding rumble strips, which are a series of depressions/bumps made into the pavement on the shoulder to provide people with an audible and tactile warning that they’re about to drive off the road. This issue impacts bicycling because rumble strips can cause major headaches if installed without bicycle riders in mind.

Here’s a snip from an email PBOT’s Jeff Smith sent to OBRA:

“Obviously, there are some very real potential safety benefits for cyclists from using rumble strips — but they also create some very real concerns.”

PBOT is a very bike-sensitive agency, so if they install rumble strips, I’m sure they’ll do it in a way that has the least amount of negative impacts. The fact that they’re reaching out to bike groups at this early stage bodes very well.

According to Smith, PBOT would adhere to Federal Highway Administration guidelines, which call for four feet of width between the rumble strips and the edge of the roadway and 12-foot gaps every 40 to 60 feet.

Smith says the rumble strips on Marine Dr. would “conform closely to the League of American Bicyclists’ recommendations” as laid out in this League blog post.

If you have feedback about the use of rumble strips on Marine Drive, PBOT would love to hear it. Please consider leaving a comment below and/or emailing Jeff Smith at directly jeff.smith [at] portlandoregon.gov.