setup Remote for Traffic Lights

There have been some concerns that unauthorized people may have obtained devices that can trigger light preemption. The original 3M Opticom pre-emption system was activated by a 14 Hz strobe light added to the light bar of fire trucks, ambulances, and squad cars. When the sensor senses the 14 Hz strobe signal, the pre-emption is activated. The 14 Hz "secret" was eventually discovered, and MIRTs (Mobile InfraRed Transmitters) hit the market, consisting of a 14 Hz strobe with an infrared filter installed on it to make the light invisible to the naked eye. The use or sale of such devices in an unauthorized context was made illegal in the United States in 2005.

In some jurisdictions, traffic lights are set to turn red in all directions when the pre-emption system is activated, rather than holding one direction green to allow an emergency vehicle to proceed with traffic. This stops all traffic except for emergency vehicles, which are permitted to proceed through a red signal anyway, and thus removes much of the incentive for an unauthorized person to manipulate the pre-emption system to their own benefit.

3M has developed an encrypted Opticom system.[5] However, jurisdictions already using the original system would have to replace the original traffic signal sensors and vehicle-mounted emitters in order to use the encrypted system.

There have been recent concerns about the security of traffic light preemptive systems and the actual underlying network controlling them and traffic lights in general. An article in the hacker E-zine Phrack has outlined flaws in the traffic controlling system that could allow an unauthorized malicious person to abuse it as he sees fit. By issuing valid signal controlling messages from the area traffic control center if access is gained to it, an attacker could essentially control any phase, test phase, preemptive signals, or any function of the traffic system that is controllable remotely. The article also sparked a response by Transport for London where it is reported that a skilled attacker armed with this “step-by-step” guide could in fact cause malicious damage, as reported by a Transport for London spokesman..