https://www.mutcd.fyi/11r1/part-2g-preferential-managed-lane-signs/
MUTCD Part 2G — Preferential and Managed Lane Signs - MUTCD 11th Edition, Revision 1
Preferential lanes are lanes designated for special traffic uses such as high-occupancy vehicles (HOVs), light rail, buses, or taxis.
managed lanemutcdpartpreferentialsigns