Driving & Driving Test Tips: malfunctioning signal lights, traffic signals, signal lights

Question
Could you provide information on reports and /or causes of traffic signals which show green lights on all sides, thus leading to accidents?
Thank you

Answer
Usually this could happen with the older units that were mechanical in turning the lights on and off, but now most large municipalities use digital lights that are constantly monitored.  If there is a big malfunction they will usually change to all red.  If you suspect a malfunction the local transportation department will have records of repairs for lights at an intersection.  These records are open to the public or can be subpoenaed.