R3 Series — Turn and Lane Use Signs

The R3 Series covers regulatory signs that control turning movements, lane-use requirements, restricted movements, and channelization at intersections and roadway segments. This series includes turn prohibitions (No Right Turn, No Left Turn, No U-Turn, No Turns), channelization instructions (Keep Right, Keep Left), turn-only mandates (Right Turn Only, Left Turn Only), and movement permissions. In California work zones, R3 signs appear wherever lane closures, median work, or roadway realignment changes which movements are permissible at an affected intersection or approach. They carry the same legal weight as all regulatory signs and must be authorized by the agency with jurisdiction over the roadway.