https://en.wikipedia.org/wiki/High-occupancy_vehicle_lane
https://vtpi.org/tdm/tdm19.htm
A bus lane will always have more potential to move more people than a HOV lane.
https://www.drivesmartbc.ca/lanes/qa-bus-and-hov-lanes
Even if a vehicle is carrying 4-5 people in a HOV lane, a bus carrying 40-50 people is still much more efficient transportation.
https://www.liveabout.com/high-capacity-articulated-or-double-decker-2798841
https://www.reddit.com/r/fuckcars/comments/w9zja7/whenever_im_riding_the_bus_this_question_keeps/