What does a white diamond symbol on the road represent?

The white diamond symbol on the road indicates that the lane is designated for high-occupancy vehicles (HOV), which typically require a minimum number of passengers, usually two or more. This is intended to promote carpooling and reduce traffic congestion by encouraging multiple individuals to travel together in a single vehicle. HOV lanes can improve travel efficiency for those who meet the passenger requirement by allowing them to bypass slower-moving traffic in adjacent lanes.

In contrast, a pedestrian crossing zone is marked with different symbols or signage, and construction zones are indicated by orange signs and additional warnings to alert drivers of the presence of workers and equipment. Speed limit signs use a different format and color to set legal speed limits for specific areas, further differentiating them from the meaning of the white diamond symbol. The specific visual and functional distinctions of road markings and signs are designed to communicate important information to drivers effectively.