On streets that don't have enough justification to add a bus lane (low headways), we might consider allowing high-occupancy vehicles to use the lane as well. On streets, though, the threshold should more than two, which is common on freeways. The threshold should be higher so the lane keeps its intent to move people more quickly. Non-transit buses, shuttles, and vans should be allowed in. Perhaps the threshold could be 4 or 5 people per vehicle.
However, on streets with high bus ridership and headways, buses should be exclusive to the lane. Signage should clearly identify whether the lane is "bus only" or "HOV 5+".
Suggestions for HOV 5+ streets include Olympic, Beverly Blvd, Sunset, La Cienega, Venice, Lincoln, and Ventura Blvd.