There's a school of thought that says that if the lights are designed to change when traffic approaches but they don't, then they are defective, and you can proceed with caution just as if you would if they were more comprehensively broken. I don't know whether this is explicitly mentioned in legislation or has been tested in court.I appreciate this is illegal but the only way is to wait till a car going your way trips the sensors.
Any thoughts?
You can also complain to the council who may be able to adjust the sensitivity. Though whether it stays adjusted the next time work is done to the lights for any other reason is another matter ...