(Portland Bureau of Transportation)
Bike-friendly speed bumps have felt like something of an underdog since they burst onto the scene in 2017. But that would change if Portland’s head bike planner has any say in the matter.
Speed bumps with channels cut through them to ease the way for bicycle riders have elicited a variety of opinions over the years. Some say they make biking more comfortable and attractive, while others find them annoying and worry about costs given other priorities. For the Portland Bureau of Transportation (PBOT), the jury had been out — even after years of use in the field.
Now results are in from a PBOT survey conducted over the summer: “PBOT recommends that bicycle-friendly speed bumps be the preferred speed bump used for neighborhood greenways,” reads a 10-page report authored by PBOT Bicycle Coordinator Roger Geller published Thursday ahead of a meeting of the city’s Bicycle Advisory Committee on Tuesday (March 12th).
The first mention of bike-friendly speed bumps on BikePortland was January 2017 when we got wind that PBOT would test them on the SE Clinton Street neighborhood greenway. Since then, PBOT has rolled them out on 10 greenways citywide: N Kilpatrick, Michigan and Wabash; NE Alameda, Davis and Everett; SE Ankeny, Clinton and Woodward, and SW 60th. When they came to a greenway in my neighborhood, I was eager to sing their praises.
[Above: A new “Bike Bump Map” created by PBOT shows bike-friendly speed bump locations (in green) relative to the city’s emergency vehicle corridors.]
The impetus for giving bike riders a break from bumps comes from the irony that in order to get drivers to slow down to the 20 mph speed limit on streets where bicycling and walking is prioritized, speed bumps are a necessary evil. And I say “evil” because hitting a bump while riding is uncomfortable and inefficient — especially when riding at higher speeds on downhills or near the speed limit (much easier these days thanks to electric bikes). Hitting bumps isn’t just annoying, it can cause damage to your property when cargo is jostled and/or falls out of a rack or bag. (Keep in mind that unlike automobiles, most bikes ridden in the city have very little or not suspension.)
In addition to real-world use, PBOT wanted more direct feedback to make a final decision on whether or not to keep bike-friendly speed bumps alive. So they did a survey last summer. The report that will be discussed at the BAC meeting Tuesday night summarizes what PBOT learned from the 543 people who responded to that survey.
Three charts from the report.PBOT’s survey wanted to find out three things: Do people actually like to bike through the channels? Should sharrow markings line up with the channel? And, what should PBOT do if the bikey bumps cost more?
A whopping 80% of the 543 survey respondents said they prefer riding through the bicycle-friendly bumps (note that PBOT refers to the bumps as speed “cushions”). And since Portland’s adopted bicycle design policies encourage them to build the “highest quality bikeways” possible and to, “maximize comfort and minimize delays” for people bicycling; this finding had major sway in PBOT’s recommendation. “This strong preference for the channels suggests that the channels represent a higher quality design than standard speed bumps. In that sense, their use better support our design policies (“Build the highest quality bikeways”) than do standard speed bumps,” states the report.
65% of respondents liked the idea of the sharrow pavement marking being aligned right at the channel to help orient them through.
When it came to cost, a slight majority of respondents recommended installing the cushions despite a potential 10% premium on cost (survey went out before the 20% premium number was known), 40% said to save money, and 9% had no preference.
With funding such a major issue at PBOT, the report took a close look at the cost difference between the bike-friendly cushions and traditional bumps. Geller and his team analyzed nine projects and found the bike-friendly version costs 20% more. But when Geller looked deeper into the numbersand had engineers estimate how many regular speed bumps would have been required for the same project, he found there was actually “no or only minimal cost difference.” In the end, Geller says each project should be evaluated independently when/if cost is an issue.
The report also weighs in on a few key concerns about the bumps expressed by some in the community: That drivers use the channels and swerve dangerously while doing so, and that the channels can cause some riders to crash or bobble and/or be a problem for folks with trikes and other unconventional rigs.
Here’s what the report says about drivers using the channels:
Our speed data indicate that even though people may get one wheel in a channel it does not affect speed. However, that doesn’t mean that people don’t try. . However, the observation is that while people driving may deflect toward the channel when there is nobody else on the roadway. When somebody else is on the roadway, people driving stay in their lane.
And here’s what the report says about bike riders crashing in the channels:
Regarding that the cushions can contribute to crashes: there have been no reported crashes on the cushions to date. When initially deployed, PBOT staff attempted to ride erratically through the channels at different speeds and angles of approach to see if the channels created discomfort in riding. They did not.
This report makes it clear that if PBOT’s bike coordinator has his way, the bureau will make bike-friendly bumps the standard going forward.
Stay tuned for input from BAC members after Tuesday night’s meeting and take a look at the full report yourself here. You can also learn more on PBOT’s website.
