Traffic engineering consists of traffic studies and the design of traffic signs, signs, and markings.  Traffic studies are used to determine if there are changes needed for traffic signals, 4 way stops, and speed limits.  They also look at conflict management and crash locations for ways to reduce the crash frequencies.  When a study concludes that a new device in warranted, engineering staff designs the traffic signals, signs, and/ or markings needed to make the improvement.  All traffic devices are installed in accordance with the Manual of Traffic Control Devices (MUTCD).