Study Details
Study Title: Evaluation of Safety Benefits and Potential Crash Migration Due to Shoulder Rumble Strip Installation on Freeways in Connecticut
Authors: Smith and Ivan
Publication Date: 2005
Abstract: With the encouragement of the Federal Highway Administration, many states are installing shoulder rumble strips to help reduce the number of run-off-the-road crashes. In 1996, Connecticut began full-scale installation of shoulder rumble strips on limited-access highways (freeways). This paper describes research aimed at answering three questions about the effectiveness of this project: 1) Do rumble strips actually reduce single-vehicle, fixed-object crashes? The analysis indicates that installing shoulder rumble strips reduced these crashes by 33 percent. 2) Are there certain roadway factors that influence the rate of these crashes with regard to the rumble strip installation locations? In the sections where rumble strips were installed, run-off-the-road crashes were reduced by as much as 48.5 percent in interchange areas and as little as 12.8 percent on sections of roadways where the speed limit is less than 65 mph. 3) Is the potential adverse effect of crash migration (from locations with rumble strips to those without) occurring? The roadway factors analyzed as well as sections of longer routes in Connecticut both indicate increases in run-off-the-road crashes where rumble strips were not placed, even when controlling for exposure. These findings indicate that for rumble strips to be most effective along freeways, consideration should be made for continuous installation to both reduce crashes where they are installed and avoid increases in crash occurrence where they are not.
Study Citation: Smith, E. B. and Ivan, J. N., "Evaluation of Safety Benefits and Potential Crash Migration Due to Shoulder Rumble Strip Installation on Freeways in Connecticut." 2005 TRB 84th Annual Meeting: Compendium of Papers CD-ROM, Vol. TRB#05-1299, Washington,D.C., (2005)
CMFs Associated With This Study
Category: Shoulder treatments
Countermeasure: Install shoulder rumble strips
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.66 | 34 |  | Run off road | All | Principal Arterial Other Freeways and Expressways | Rural |
| 0.84 | 16 | | Run off road | All | Principal Arterial Other Freeways and Expressways | Rural |
| 0.66 | 34 | | Run off road | All | Principal Arterial Other Freeways and Expressways | Rural |
| 0.62 | 38 | | Run off road | All | Principal Arterial Other Freeways and Expressways | Rural |
| 0.64 | 36 | | Run off road | All | Principal Arterial Other Freeways and Expressways | Rural |
| 0.68 | 32 | | Run off road | All | Principal Arterial Other Freeways and Expressways | Rural |
Countermeasure: Install shoulder rumble strips on illuminated highways
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.59 | 41 | | Run off road | All | Principal Arterial Other Freeways and Expressways | Rural |
Countermeasure: Install shoulder rumble strips on unilluminated highways
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.79 | 21 | | Run off road | All | Principal Arterial Other Freeways and Expressways | Rural |
