What does a lane marked with a diamond shape indicate?

A lane marked with a diamond shape specifically indicates that it is a carpool or occupancy-restricted lane. These lanes are designed to promote the use of high-occupancy vehicles, thereby reducing traffic congestion and promoting carpooling as an environmentally friendly option. The diamond shape is a universal symbol for this type of lane, clearly signaling to drivers that specific rules apply regarding the number of passengers a vehicle must have to legally use that lane.

Individuals in solo vehicles or those not meeting the occupancy requirements are typically prohibited from using these lanes during designated hours. This distinction is essential for encouraging greater vehicle efficiency and reducing the number of cars on the road. Highway signage, often accompanying the diamond marking, further clarifies these restrictions and helps drivers understand the proper traffic flow in these special lanes.