Rumble Strip - Transverse Rumble Strips (TRS)

Transverse Rumble Strips (TRS)

Transverse rumble strips (TRS) may be used to warn drivers: of the need to stop (e.g. intersections, toll plazas); the need to slow down; the need to change lanes; of a change in roadway alignment; that they are leaving the traveled way; upcoming construction zones; wildlife crossings; and other potentially unexpected conditions.

As a speed reduction measure TRS have been marginally successful. A 2003 Texas study concluded: "However, the actual reductions in speeds have been in the range of 2 to 8 mph (3.2 to 12.9 km/h), which may be barely perceptible to the traveling public. There have been no studies that evaluate the reduction of excessive speeds."

As a construction zone safety measure the effectiveness appears unclear. A 2007 Minnesota study indicated: "While the study concluded that transverse rumble strips offer a lowcost and easy-to-install option, they “did not seem to be successful at reducing approach speeds at the project sites.” A 2005 Maryland study stated: "In conclusion, although in the present study rumble strips did not produce the desired speed reduction effect, its use for work zone applications is still highly encouraged; though, not as a speed control measure but as a driver’s attention-catching device."

As an approach stop-control crash reduction measure they have proven successful. The 2003 Texas indicated: "The majority of studies found reported large reductions (40 percent to 100 percent) of accidents after installing transverse rumble strips."

In Ghana, rumble strips running across the entire carriageway were installed at Suhum Junction on the main Accra-Kumasi highway and reduced crashes by about 35% and fatalities by about 55%. By reducing speeds the environment for and safety of pedestrians was improved with a decline in the "hit pedestrian" crash rate of 51%. "While the enforcement of speed limits by traffic police may not be affordable for most developing countries, rumble strips and speed humps were found to be effective on Ghanaian roads."

A 2009 FHWA intelligent systems study suggested that a combined infrastructure-based and in-vehicle warning could be highly effective in reducing crossing path crashes and fatalities at signalized intersections.