Final answer:
The symbol for an HOV lane is typically a diamond, designed to indicate a lane reserved for vehicles with a high number of occupants to promote efficient travel and reduce congestion.
Step-by-step explanation:
The symbol that indicates a High Occupancy Vehicle (HOV) lane typically features an image of a diamond. This diamond symbol is often white on a blue background and is displayed on road signs above or beside the HOV lane itself. These lanes are usually on highways and are reserved for vehicles with a high number of occupants, such as carpool vehicles, to encourage fewer vehicles on the road and reduce traffic congestion and pollution.