Last week FHWA sent out new guidance to the states regarding rumble strips (see attached). These guidelines replace the Roadway Shoulder Rumble Strips from December 2001. Essentially it talks about the effectiveness of rumbles and then advises states on a number of issues, with one issue being that states should use mitigation strategies for rumbles in instances where a shoulder is less than 4'. It practically mirrors the standards that TDOT adopted last year.
Jessica L. Wilson, Bicycle and Pedestrian Coordinator