How effective are HOV lanes?

Dear Veep:
Did my name provide a clue to my most passionate topic? HOV lanes can and do accommodate more people in actual freeway counts. Each morning on I-5, 5,200 people are carried in the HOV lane compared with 2,500 in each regular lane.

HOV lanes provide room for added capacity and increased growth, because they can carry more than double the number of people in the same amount of space, and that number will continue to grow as more people are motivated to ride the bus or carpool by predictable speed and reliability.

Wouldn't the same people still use transit or ridesharing without HOV lanes, you might ask? A 1999 Commuter Profile of 3,600 commuters in the San Francisco Bay Area revealed that 64 percent of those currently using the bus, vanpools or carpools would not continue to do so if the HOV lanes were eliminated. If 64 percent of Puget Sound HOV users were to switch to driving alone, it would add 3,000 vehicles to southbound I-5 during the peak hour – one and a half lanes full of traffic to the existing peak-hour congestion.

On I-5, the most heavily congested freeway in the state, average HOV lane use has grown by approximately 30 percent since 1995. In contrast, general purpose traffic has grown by 10 percent during the same period. Those are the facts, and my marvelous initials are...
HOV