The City of Newport Beach had an early application - Back Bay Drive is a one way street upstream (with sharrows) and a contraflow bike lane downstream. Posted DO NOT ENTER for wrong way drivers with the BICYCLE EXEMPT signs below each one.
Now they are also using it as Caltrans' designated it as one option for permitting a cyclist to not obey a RTOL.
Examples are popping up on PCH in Newport Coast and at a few RTOLs in Irvine.
R118 (CA) is a California specific regulatory sign.

Infrastructure Review Committee

Area Liaison to Caltrans District 12