rumble strip 
noun
A series of raised strips across a road or along its edge, changing the noise a vehicle’s tyres make on the surface and so warning drivers of speed restrictions or of the edge of the road.It was more effective than a speed limit sign, or a rumble strip, disfiguring stripes on the road or pious notices imploring drivers to take care....
- Know the warning signs of drowsy driving, such as not being able to remember the last few miles driven or hitting a rumble strip.
- Cycles do use the ring road, the area between kerb and rumble strip seems to be used as an unofficial cycle track.