Rumbling Rumbling Rumbling

Twice now I’ve had good folks tell me to beware the spread of rumble strips. Twice I’ve said I don’t much care because 99% of my riding is in the city. When I have encountered rumble strips, they haven’t bothered me a wit. In fact, I have taken comfort in the fact that the strip could alert a motorist to an impending departure from the road (with me in their path). Maybe I am missing something. When people take time to suggest I consider something, I should look a little closer.

Rumble strips are the grooves carved into highways which alert motorists that they are headed off the roadway. They save motorists’ lives. I motor, so someday they could save my life. Some people who pedal are crying foul, however, because riding over rumble strips is uncomfortable and potentially dangerous. Here is one video smack down of rumble strips in Massachusetts:

Looks pretty bad, right? Maybe, but objecting to this particular rumble strip without qualification diminishes the value of the lives that can be saved (whether motoring or pedaling). The rumble strip in the preceding video was placed on a highway with a huge shoulder to the right of the strip. This well-placed strip will reduce the chance of a drowsy or otherwise impaired motorist drifting off the road and into a bicyclist. They can also alert a drowsy or otherwise impaired cyclist before they drift into traffic. The videographer says he has trouble negotiating the strip, but doesn’t crash. He says he was too scared to travel at speeds traveled by “good cyclists” which “go 25-30 miles per hour.” That gets my hackles up straight away. Good cyclists travel at safe speeds, taking into consideration the surface, surroundings, weather, traffic and their equipment. I suspect when the videographer refers to good bicyclists, he means racers. Racers are more likely to go 25-30 mph. One of his specific objections to this rumble strip is that racers use the highway and need to ride many abreast. Roads are not for racing. I say design roads to be as safe as possible for travelers, not racers. Onward.

Here is a video showing another rumble strip, this one in Georgia.

This rumble strip is another matter entirely. It is poorly placed and makes life worse for cyclists. There is no shoulder outside the strip. Most riders would ride to the left of this strip, placing cyclists closer to cars and eliminating a safety barrier that could have been established had the strip been placed further out into the roadway. Probably not sufficient room here. Either the strip should not have been ground into the pavement or the road should have been widened at the same time. Another likely result of the strip as placed is that cyclists will find another place to pedal. Maybe that’s fine if you are pedaling for pleasure, but what if you work at the other end of that road? What if all the roads had poorly placed rumble strips?

We are at a crossroads in New York State. The New York Department of Transportation (“NYDOT”) is testing rumble strips in our state. You can read all about it here. They started with freeways back in 1978 (where bicycling is not allowed) and claim to have done so specifically in consideration of bicyclists. That might have been the case, as bicycle touring was a big deal at the end of the previous oil crisis. Now the NYDOT is “developing a draft policy on the limited installation of shoulder rumble strips on secondary highways.” This is where people who like to ride in the country often pedal.

From my seat, it looks like the NYDOT is doing a good job of balancing the interests of people in cars versus people on bicycles. Check this out:

The current draft design guidance for rumble strips on secondary highways differs substantially from freeway rumble strips, to avoid adverse impacts to bicyclists, as follows:

Feature Freeway Secondary Roads
Gaps for Bicyclists Not Applicable 10′ gap every 60′
Groove Depth 1/2″, 5/8″max 1/2″ max
Spacing between Grooves 12″ 24″
Width of Groove 16″ 12″
Offset from the Traveled-Way 10″ on asphalt right shoulders 4″ on Portland Cement Concrete and left shoulders 6-12″
(Note 1)
Remaining Shoulder for Bikes N/A 4′ min
(Note 2)
Maximum Downgrade None 10%, Unless a crash problem

1. A 0” offset may be acceptable on facilities with a run-off-the-road crash problem based on a site specific crash study, where additional noise is unlikely to result in numerous complaints, or where a parallel bike facility is within 200’.
2. Less than 4’ may be acceptable where a parallel bike facility is within 200’.

I have no objections to the proposal. It looks like we will get at least four feet of road to the right of a rumble strip and a chance to move to the right of a strip every 60 feet without having to travel over the strip. Sounds dreamy to me. What am I missing? Why did a NYDOT representative tell me to change my focus to rumble strips? I understand why racers may be upset, but, again, the roads are not playgrounds. Very serious business is transacted there. If you need to go fast in a pack, rent time at a local racetrack or build a new velodrome. I’ll pitch in!

Also, don’t forget the importance of proper equipment choice. Skinny high pressure tires on stiff short wheelbase frames with steep headtubes (racing bicycles) seem poorly suited to traveling over a rumble strip. If you ride frequently on highways with rumble strips and you find yourself pedaling over them, install fatter tires and run them with lower pressures. This will cushion your ride, help you hold a line and, frankly, slow you down a bit which isn’t always a bad thing. Better still take out a bicycle designed for cyclocross, touring or transportation. Their generally relaxed geometry, higher bars and clearance for fat tires will together help get you over a rumble strip safely when the need arises.

A great video on rumble strips from the USDOT can be viewed here. Get a snack before you hit play (it runs for 15 minutes). A couple of things worth highlighting. It mentions that rumble strips can be designed to minimize impact on bicycles and motorcycles, but it doesn’t give details. Clues maybe. The video describes four types of rumble strips and details the two most commonly used–milled and rolled. Milled are cut into the surface of an existing roadway and rolled are impressed into freshly laid road surfaces. According to the video, milled are 12.6 times rougher and are 3.4 times louder when driven over. So milled may give the greatest flexibility in application and may enhance the lane departure safety effects, but we should know whether rolled rumble strips might have a less detrimental impact on pedalers. Again, I am currently in favor of well placed rumble strips because of the lane departure warnings they provide, but I will ask the NYDOT for details regarding the various types of strips and their suitability for bicyclists. The video also describes rumble stripes, which are simply white stripes painted over the top of rumble strips. The stripes enhance the safety benefits of strips by offering an enhanced visual cue as to the location of the edge of the roadway (if you are operating a car) or the shoulder (if you are pedaling a bicycle). Maybe we should ask the NYDOT to require pairing of stripes with strips.

Want more? Read this piece from the League of American Bicyclists. The League suggests many detailed improvements relating to placement and design of rumble strips (and could form the basis for any comments to be submitted to the NYDOT). More still? You are eager! Here is a blog on the Times Union site on the topic. Just can’t get enough? Good information can be found at the New York Bicycle Coalition site here. So much more is to be found using the Goggles, but tighten your toe straps first, kids. You are in for en epic ride.

What am I missing? Poke holes in my arguments in favor of well placed rumble strips. Provide important details I have missed. Drop a link to your post on the subject below. Share your experiences. Tell me where to find these strips and I will try to go pedal on them.

Once you are up to speed on the issue, if you have a gripe with, a refinement to or simply support the NYDOT proposal, the time to contact them is now. The NYDOT wants to educate and hear from you. For additional information, please visit the FHWA website: preceding external link opens a new browser window
or contact Richard W. Lee, P.E.:

Warmer weather approaches!


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