For example, in California you can use the carpool lane even if you are driving alone.

FORBES: How Long Until Your Hybrid Pays Off?

She even taught us to unfasten the T-tops and slide each one into car's hatchback trunk, while we wait in the carpool lane at school.

NPR: Who's Your Grandma? These Days, Nobody Is

According to the MTA's plans, the agency will realign the existing six lanes on the upper level of the Verrazano to make room for a new seventh lane in the middle of the bridge, which would be open only to buses and carpool vehicles.

WSJ: Plan to Aid Staten Island Commuters