Rumble Strip Action

Rumble Strips

The way our roads are built affects everything in our lives.  Everything, yes, though we’ll just focus for now on how rumble strips affects the lives of cyclists.  If a rumble strip is applied on a cyclist’s favored route, that cyclist will probably dissuade all their friends from returning.  It doesn’t matter whether that route was used by a geared-up road cyclist or a daily commuter.  They had a right to be there.  Period.  And because it’s been rendered unsafe by a massive gouging in the road, there’s no reason to use it.  It might as well have received a stamp that said “For Cars Only”.

Rome wasn’t built in a day.  It takes years.  Years of guts, courage, accrued knowledge, tuned cadence, tact, and learned foresight. 

A story usually starts at the beginning, but that’s not the case with this one.  I started as the Executive Director of PCC in August 2012, so that the former ED, Rachael Bronson, could pursue a Master’s degree in transportation engineering, with a bike focus.  We hope she eventually chooses to return to get an engineering job building more bike lanes here in our State. 

Rachael had been working with SCDOT on the rumble strip issue for the last several years.  She worked with them on many aspects of how they applied rumble strips around the entire state.  You see, SCDOT knows how to build roads for motorists, but they are understaffed with people that can figure out how to prevent ruining the road for bicyclists.  So Rachael took the good road and worked to help SCDOT.  She worked hard to help them craft an internal engineering directive (EDM) on how these rumble strips would be be applied so bicyclists could still use the public thoroughfares their federal income tax supports.  Rachael had worked with them on writing the policy to include protection from rumbles for roads with low traffic volumes, speed limits under 45mph, and any of the 6 SC Bicycle Touring routes.  That’s as far as they would go in excluding certain roads from rumble consideration.  Then if any of the rest still had high car fatality data and SCDOT insisted on still rumbling, she negotiated for compromise rumble engineering that better accommodated both users.  SCDOT took her input and created their own internal policy.  Rachael and PCC didn’t have final say on that.  They went ahead and applied rumble strips across the state using some of Rachael’s recommendations, though doing it their way.  Rome isn’t built in a day.  And SCDOT is a mountain. The mountain moved, and it moved all on its own and of its own accord. 

The rumble strips were applied and misapplied, but in both cases the result was the motorist came out way ahead of the cyclist in safe street design.  At one point after many, many of those rumble strips had already been applied, SCDOT reached out to us beyond what the EDM required and asked what we thought about rumble plans for a long list of routes not part of the state bike tour network (the 6 routes).  We responded back with answers, and they altered some plans.  Complicating this were inconsistencies between what various contractors understood to be the actual meaning of the EDM.  SCDOT knows this, and it’s up to them to fix it.  In sum, what happened in communications between SCDOT and its contractors is a mystery.  We have recent assurances they are going to fix this problem.  

Action Plan
Our current work is collaborating with SCDOT on an update to the current Rumble Strip EDM.  We have high expectations for SCDOT, and we communicated this.  We set the expectation that they understand these concepts: 
  • Misapplied rumble strips are creating an unsafe condition for bicyclists, and PCC wants to help SCDOT with EDM 53 to assist them in their primary responsibilities for maintaining safe roads for all users,
  •  In addition to the statewide Bicycle Touring Guide (6 routes), additional bike route maps should be utilized to filter routes from the rumble strip list. 
      • Statewide Geodatabase of all municipal/county/MPO/COG Bike Master Plans (by ALTA Planning: currently fulfilling SCDOT contracted work)
      • East Coast Greenway map
      • Top recreational bike route maps from established Cycling Organizations,
  • The rumble strip team should talk with contractors, before letting projects, to ensure rumble strip applications are standardized,
  • When a bicycle route is the same as a route that motorists are known to have high run-off-the-road fatality rates, these are potential compromise rumble strips design standards that should be negotiated with stakeholders for use instead of traditional rumble strips designed solely for cars:
    • 3/8” rumble strip depth
    • rumbling stripE’s (rumble under the stripe)
    • a 4”-6” milled in rumble stripe (pending further study on efficacy by SCDOT)
  • When applying rumble strips near potential bike obstructions, utilize skip pattern to the fullest extent,
  • If rumble strips must be applied on a road with no shoulder, it’s best to utilize the narrowest possible width, and as close to the edge line as possible,
  • Reference the 2012 AASHTO Guide to the Development of Bike Facilities, chapter on rumble strip integration,
  • As a statement of principal, rumble strips should be applied only on roads SCDOT sees in their long term investment plan, including:
    • Interstates
    • Numbered system highways
    • Principal arterials

Our next step is to return to SCDOT and work with their feedback.  Stay tuned.  As time permits, we’ll publish more renditions of our other projects slated for work this year:  Safe Streets Save Lives campaign on bicycle safety education, MAP-21 state transportation funding prioritization, SCDOT Street Design Manual, recreational bike route map collection, LCI classes, and driver education.

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5 responses to “Rumble Strip Action”

  1. Appreciate your work on this. Rumble strips are no fun on any road, but sometimes they can be rideable anyway when applied correctly and there is a shoulder. I have been on some roads where the rumble strip is positioned so that it leaves only a few inches of shoulder. Rather than trying to balance and accidentally run over the trip, it is easier to ride out in the lane. I know DOT can be difficult, but do you think we can ever get the strips paved where they were misapplied? If so, would they ever pave a strip that interferes with a major cycling route where there are no vehicle fatalities?

  2. Great questions! Any future road repaving will effectively remove a rumble strip. Unfortunately, PCC doesn’t have the resources to do a full scale effort towards remediation (scrape or repave) on a road-by-road basis throughout SC. We encourage you take that on at the local level and use us as a technical resource to help you know if rumbles were misapplied using the old EDM. You can write a letter on behalf of your local Bike Club to your SCDOT Commissioner or House Representative.

    Our head at this point is on future policy changes to make real change, albeit in the future and not now. We know some rumbles were definitely misapplied, and we also know of current efforts to remediate those mistakes. However, we were only told of a subset of their previous plans to rumble, meaning we didn’t have control over everything. As far as future capacity for policy change, we encourage you to work with your local Bike Club to identify preferred routes for future protection, based on our EDM rewrite. Then when we get in touch with this Club and all others in SC, we’ll collect those routes into a SC list that will be a 1st filter to future rumbles. Contact [email protected] if you’d like to talk further, and thanks for your questions.

  3. Just noticed today that Rt 17 in West Ashley (Charleston) and west thereof, has what little of the part to the right of the white line now taken up by rumble pits. This appears to have been done the last coupla days.

  4. It might as well have received a stamp that said “For Cars Only”.

    Absolutely true. Interestingly enough, no fuel taxes or use taxes are paid by cyclists. No property taxes are paid on bicycles. So evidently motorists are supposed to allow bicyclists to freeload and make demands without having any “skin in the game.” That is simply wrong.

    Cyclists need to understand that there is another very legitimate side to this issue. Rumble strips are PROVEN to reduce traffic fatalities. There is NO QUESTION about that. I’ve had one save my life. Roads were designed for motor vehicles, and are generally paid for by taxes paid on vehicles and fuel.You are NOT a stakeholder if your use of the roadways is without cost.