Commuter lanes, often referred to as carpool, diamond, HOV, high occupancy, or express lanes, were created to reduce the number of cars on the road. It was thought this would further reduce U.S. dependency on foreign oil and air pollution. Recent census data indicates this is not working, however. Commuters using diamond lanes have dropped nationwide from 20% to approximately 10.5% over the past three decades. Carpools are effective if groups of people work and live in similar locations with similar work schedules. The California Department of Transportation and county governments now allow solo drivers to use restricted lanes during commute hours if they pay for the privilege. It appears the purpose of diamond lanes now is less about the environment and more about generating revenue.
