What is indicated by a road marking for an HOV lane?

A road marking for an HOV (High-Occupancy Vehicle) lane indicates that this lane is designed to be used by vehicles with multiple passengers, typically to encourage carpooling and reduce traffic congestion. The correct answer points to the fact that HOV lanes are often restricted for certain types of vehicles, which can include buses and bicycles in some instances.

This lane usage is intended to promote public transit and efficient transportation options, thus improving overall traffic flow and reducing emissions. While HOV lanes may also accommodate certain private vehicles with multiple occupants, the specific mention of buses and bicycles highlights their role in public transportation and alternative methods of transit.

Other options do not align with the main purpose of HOV lanes. For example, private vehicle access only is misleading because not all private vehicles can use the lane unless they meet the occupancy requirement. Similarly, while commercial vehicles might be restricted in certain lanes, this is not a universal rule strictly related to HOV usage. Lastly, while ridesharing may be encouraged in HOV lanes, they are not designated parking zones, which further clarifies the importance of the intended use of HOV markings.