Va. Code § 33.2-500
As used in this chapter, unless the context requires a different meaning:
"High-occupancy requirement" means the number of persons required to be traveling in a vehicle for the vehicle to use HOT lanes without the payment of a toll. Emergency vehicles, law-enforcement vehicles being used in HOT lanes in the performance of law-enforcement duties, which shall not include the use of such vehicles for commuting to and from the workplace or for any purpose other than responding to an emergency incident, patrolling HOT lanes pursuant to an agreement by a state agency with the HOT lanes operator, or the time-sensitive investigation, active surveillance, or actual pursuit of persons known or suspected to be engaged in or with knowledge of criminal activity, and mass transit vehicles and commuter buses shall meet the high-occupancy requirement for HOT lanes, regardless of the number of occupants in the vehicle.
"High-occupancy toll lanes" or "HOT lanes" means a highway or portion of a highway containing one or more travel lanes separated from other lanes that (i) has an electronic toll collection system; (ii) provides for free passage by vehicles that meet the high-occupancy requirement, including mass transit vehicles and commuter buses; and (iii) contains a photo-enforcement system for use in such electronic toll collection. HOT lanes shall not be a "toll facility" or "HOV lanes" for the purposes of any other provision of law or regulation.
"High-occupancy vehicle lanes" or "HOV lanes" means a highway or portion of a highway containing one or more travel lanes for the travel of high-occupancy vehicles or buses as designated pursuant to § 33.2-501.
"HOT lanes operator" means the operator of the facility containing HOT lanes, which may include the Department of Transportation or some other entity.
"Mass transit vehicles" and "commuter buses" means vehicles providing a scheduled transportation service to the general public. Such vehicles shall comprise nonprofit, publicly or privately owned or operated transportation services, programs, or systems that may be funded pursuant to § 58.1-638.
"Owner" means the registered owner of a vehicle on record with the Department of Motor Vehicles or with the equivalent agency in another state. "Owner" does not include a vehicle rental or vehicle leasing company.
"Photo-enforcement system" means a sensor installed in conjunction with a toll collection device to detect the presence of a vehicle that automatically produces one or more photographs, one or more microphotographs, a videotape, or other recorded images of each vehicle's license plate at the time it is detected by the toll collection device.
"Unauthorized vehicle" means a motor vehicle that is restricted from use of the HOT lanes pursuant to subdivision 4 a of § 33.2-503 or does not meet the high-occupancy requirement and indicates with its electronic toll collection device that it meets the applicable high-occupancy requirements.
Va. Code § 33.2-500