Rumble strips exist to alert drivers when their car has veered onto the shoulder of a road or highway. Did you know that there are actually four types of shoulder rumble strips?

Rolled Rumble Strips

These rumble strips contain grooves that are either rounded or V-shaped. These strips are pressed into hot asphalt pavements and shoulders during a time when the constructed or reconstructed surface is compacted. Rather than a cutting drum, these stripe are created with rollers with steel pipes welded to a rotating drum. The vibration created from these strips are not as loud or pronounced as ones that come from milled strips but they still produce enough sound to alert drivers who happen to drift into them.

Milled Rumble Strips

Depending on the size of the groove, these rumble strips can produce various amounts of vibration as well as different pitches of sound. The general rule of thumb here is that the wider and deeper the rumble strip, the more sound and vibration are produced from them. A five to seven inch cut with a half inch of depth spaced every twelve inches seems to be the standard sizes for a milled rumble strip; however, some states are experimenting with four inch edge line rumble strips. Milled rumble strips are created with a machine that contains a rotary cutting head, much like our Rumble Hog!