Some lanes are restricted to carpools only during high-use commute hours. It is legal for single-occupant vehicles to use the HOV lanes if it is outside those HOV hours of operation. Signs will be posted along the HOV lane telling you when the lane is restricted to carpools only. These part-time HOV lanes are most common in northern California.
These freeway facilities are also called "Express Lanes" and allow single-occupant vehicles to use the HOT lane by paying a toll electronically (with a FasTrak transponder or by using a Prepaid ExpressAccount). Some HOT lane facilities have a One-Time-Toll feature. Most HOT lanes allow carpools to use the lane for free (local signs will specify this and indicate if carpools must carry a FasTrak transponder). HOT lanes may not be used by vehicles restricted to a 55 MPH speed limit. An example of a HOT lane is the Sunol Grade on Interstate 680 in the San Francisco Bay Area.
Do not cross solid, double lines whether they are white or yellow! If you are entering or exiting an HOV lane, you must change lanes only where there is a designated area or where you are crossing a single dashed line (white). In all cases, you must change lanes safely. For details, see the California Vehicle Code, Sections 21655.8 and 21460.
As of July 2, 2011, single-occupancy hybrids with yellow decals are NOT allowed in HOV lanes. More details are available at the
Air Resources Board (ARB) website External link .
If your vehicle has a red or purple decal issued by the Department of Motor Vehicles (DMV), you CAN drive by yourself in the HOV lane unless prohibited by local signs. Policies vary for other kinds of facilities (bridges, HOT lanes, Express Lanes, toll highways), so watch the local signs or ask the local CHP office. Contact the ARB for information if you are interested in electric, compressed natural gas (CNG), or other clean air vehicles.
Solo motorcyclists can use HOV lanes (and most HOT lanes) without a decal unless otherwise posted. Motorcyclists cannot ride on, in, or over solid double lines.
Under some conditions, these vehicles can use HOV lanes with single occupants. For details, see the California Vehicle Code, Sections 21655.5 and 23301.5.
Any vehicle towing a trailer, large trucks, and other vehicles subject to a 55 MPH speed limit cannot use an HOV lane regardless of the number of occupants.