Diamond lane
In the United States and Canada, a diamond lane is a special lane on a street or highway that is reserved for specific types of traffic. These lanes are usually marked with white diamonds or lozenge, hence their name. Diamond lanes are generally the right-most or left-most lane on the road. They are usually implemented to provide ways through traffic congestion, for safety reasons, and to encourage environmentally friendly transportation. A diamond lane may be intended for a specific type of traffic, or for several types. The intended use of a diamond lane is marked by  traffic signs. In most areas, violating the rules of a diamond lane is punishable by a fine. Some common examples are: In some cases, these lanes may serve multiple functions. For example, a diamond lane may be designated for buses, bicycles, and right turns. Standards. The Federal Highway Administration's "Manual on Uniform Traffic Control Devices" states that diamonds indicates a lane reserved for high-occupancy vehicles.