Downloadable software for monitoring, simulating, controlling and managing traffic; traffic control systems comprised of traffic lights, traffic signal controllers, interface devices for use with traffic signal controllers, traffic sensors, vehicle detectors, traffic sensors, dynamic digital message signs, variable speed limit signals, toll collection transponder, traffic cameras and ramp meters; computer controlled traffic light systems comprised of computers, traffic lights, traffic signal controllers, interface devices for use with traffic signal controllers, traffic sensors; electronic apparatus relating to traffic light system, namely, traffic lights, traffic signal controllers, and interface devices for use with traffic signal controllers; measuring and signalling apparatus, namely, traffic lights, vehicle detectors, traffic sensors, road weather measuring apparatus and dynamic digital message signs