The Best Rumble Strip–Rolled or Milled?

Every state highway authority that has tested both the 7-inch milled cut and the rolled-in pattern, has since abandoned rolling.

Before the introduction of the 7-inch milled rumble strip, contractors would weld a series of steel pipes to rollers and press narrow depressions into the road while the asphalt was still hot. So that the roller could indent the asphalt, rolled rumble strips had to be kept quite narrow -- usually less than 2 inches wide. Nearly all the highways currently using the 7-inch milled cut have some prior experience with rolled rumble strips.

Rolled-in patterns had some success in reducing drift-off accidents, however, they have not produced results comparable with the 7-inch milled rumble strip. Also, the rolled-in pattern has presented critical maintenance and construction problems.

Do your rumble strips work?
The 7-inch milled rumble strip has demonstrated a reduction in drift-off accidents by 70% or more. Rumble strips that do not measure up to these results may be responsible for unnecessary injury or loss of life.

Start saving lives this year.
Because the 7-inch milled rumble strip can be placed on any existing shoulder, hundreds of miles of highway can be treated in a few short months versus the 7-15 year lead time a highway might have to wait before patterns can be rolled-in during the next resurfacing.

Better Performance The Virginia Department of Transportation has determined that the 7-inch milled rumble strip generated 335% more noise, and produced 1,260% more vibration excesses (denoted on the International Roughness Index) than rolled-in patterns.*

The best alarm saves the most lives. No highway using rolled-in patterns has reported a reduction in accidents comparable to that achieved by the 7-inch rumble strip.