Traffic engineering is the branch of civil engineering that aims to achieve the safe and efficient movement of vehicles and pedestrians on roadways.
Traffic Control Devices
Devices, markings and other objects that control the movement of vehicle and pedestrian traffic are referred to as "traffic control devices." These include signs, pavement markings, traffic lights, and any other roadway features that regulate the movement of traffic. The placement of traffic control devices is carefully determined by professional traffic engineering staff.
Manual for Uniform Traffic Control Devices (MUTCD)
Citizens should keep in mind that all traffic control devices are operated and maintained by experienced engineering professionals, and must conform to state standards. To see standard design specifications for California traffic control devices, refer to the California Manual for Uniform Traffic Control Devices.