A rumblestrip is designed to act as an
early warning that your car
is drifting off the
highway. Rumblestrips are often installed on the edges of major roads and
motorways.
In the
UK. In the US, most States are increasingly under pressure from the
FHWA (Federal Highway Administration) to install rumblestrips on their roads.
I wanted to tell you the width and depth of a rumblestrip, but there are no nationally agreed rumblestrip specifications in the USA.
Instead each state makes these decisions at a local level, so Americans will find a huge inconsistency
between the width and height of the rumblestrip in different areas.
The rumblestrips that I have seen (across the motorways and
A-Roads of Britain are look like they are made of the same material as the standard white reflective lines.
They are perhaps a little wider. The main difference is that they are raised every few centimeters, which make
a rubmling noise as your tyres run over them. This pattern is made when the strip is layed on the road.
Interestingly there is a company called Dustrol Inc (USA) who are providing a grinding service.
They offer to create rubmblestrips for local DOTs by gouging small trenches in the road surface at regular intervals.
This obviously saves on materials, but does mean that you don't get a visible marking for free.