CA AB1721

Authorizes the Department of Motor Vehicles to issue distinctive decals, labels, and identifiers to low-emission vehicles (SULEV, ULEV, enhanced AT PZEV, and TZEV standards) allowing them to use HOV lanes without meeting occupancy requirements.

Grants eligible low-emission vehicles displaying a departmental identifier toll-free or reduced-rate passage in high-occupancy toll (HOT) lanes, unless prohibited by federal law or on certain toll roads and bridges.

Limits issuance of identifiers for enhanced AT PZEV and TZEV vehicles to 70,000 decals, with provisions allowing replacements for owners whose vehicles are declared total losses or nonrepairable within six months.

Requires the Department of Transportation to remove HOV lane access during peak congestion periods if lanes exceed level of service C and the vehicles would significantly increase congestion, with findings demonstrating infeasibility of alternative congestion solutions.

Sets an expiration date of January 1, 2019 or upon expiration of federal authorization, whichever occurs first, unless a later statute extends the authorization.