Effectiveness
Despite having the appearance of being lightly traveled when compared with adjacent, congested unrestricted lanes, a HOV lane carries more people per lane with fewer vehicles and usually at a higher speed than unrestricted lanes.
According to 2009 data from the U.S. Census 76% drive to work alone and only 10% rideshare; for suburban commuters working in a city the solo-driving rate is 82%.
Some underutilized HOV lanes in several states have been converted to high occupancy toll lanes (HOT), which offer solo drivers access to HOV lanes after paying a toll.
HOV lanes are also an effective way to manage traffic after natural disasters as seen in New York City after the October 2012 storm Hurricane Sandy. At the time Mayor Bloomberg banned passenger cars entering New York City with less than three occupants. The restrictions impacted all bridges and tunnels entering the city except on the George Washington Bridge.
Read more about this topic: High-occupancy Vehicle Lane