<Table> <Tr> <Td> </Td> <Td> The examples and perspective in this article deal primarily with North America and do not represent a worldwide view of the subject . You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate . (October 2013) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> The examples and perspective in this article deal primarily with North America and do not represent a worldwide view of the subject . You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate . (October 2013) (Learn how and when to remove this template message) </Td> </Tr> <P> Rumble strips, also known as sleeper lines, alert strips, audible lines, sleepy bumps, wake up calls, growlers, drift lines, and drunk bumps, are a road safety feature to alert inattentive drivers of potential danger, by causing a tactile vibration and audible rumbling transmitted through the wheels into the vehicle interior . A rumble strip is applied along the direction of travel following an edgeline or centerline, to alert drivers when they drift from their lane . Rumble strips may also be installed in a series across the direction of travel, to warn drivers of a stop or slowdown ahead, or of an approaching danger spot . </P> <P> In favorable circumstances, rumble strips are effective (and cost - effective) at reducing accidents due to inattention . The effectiveness of shoulder rumble strips is largely dependent on a wide and stable road shoulder for a recovery, but there are several other less obvious factors to consider during design . </P>

Road safety feature by means of change in tyre noise