Civil & Forensic Pty Ltd ©  Andrew Brown

Traffic Signal Analysis      Definition: "Traffic Signals are devices which, by means of changing coloured lights, regulate the movement of traffic"  - Source Book for Australian Roads, MG Lay     Traffic movements at Australian road intersections are usually controlled by a formal traffic control, such as Give Way signs, Stop signs, T-Intersection rule, Roundabout or Traffic Signals.  With the exception of Traffic Signals, these controls are static (they do not change over time).  Traffic Signals, by their very nature are dynamic (the traffic movement that has right of way changes periodically).   When an accident occurs at an intersection controlled by Traffic Signals there are often conflicting versions on which vehicle had right of way.  Although Traffic Signals are dynamic controls, there is no log kept of what traffic light is green at what time.  In addition, most traffic signals are designed to respond to traffic and pedestrian demand rather than follow a fixed allocation of time for each traffic movement.  Also, in major urban centres traffic signals are often controlled by advanced computerised systems such as SCATS (Sydney Coordinated Adaptive Traffic System), which coordinate groups of traffic lights to improve traffic flow.   Traffic Signal Analysis. We can analyse the operation of traffic signals at an accident site and provide advice on the viability of opposing accounts of the accident.  Our report includes: analysis of the traffic signals as they existed at the time of the accident. copy of the traffic signal plan for the intersection. description of the phases that operate at the intersection. description of the timing for each phase of the traffic signals (minimum and maximum green times, amber time and all red time). check of recorded faults for the date of the accident (optional). check on the viability of opposing accounts of the accident and independent witness accounts.       Last modified on 04 October 2007 by Andrew Brown of Civil & Forensic Pty Ltd