Editing Traffic (section)

===Pre-emption===
In some areas, [[emergency service|emergency responders]] are provided with specialized equipment, such as a [[Mobile Infrared Transmitter]], which allows emergency response vehicles, particularly [[Fire apparatus|fire-fighting apparatus]], to have high-priority travel by having the lights along their route change to green. The technology behind these methods has evolved, from panels at the fire department (which could trigger and control green lights for certain major corridors) to optical systems (which the individual fire apparatus can be equipped with to communicate directly with receivers on the signal head). In certain jurisdictions, public transport buses and government-operated [[winter service vehicle]]s are permitted to use this equipment to extend the length of a green light.<ref>{{citation |mode=cs1 |section=625 ILCS 5/12-601.1. Traffic control signal preemption devices. |title=Illinois Compiled Statutes |url=http://www.ilga.gov/legislation/ilcs/documents/062500050k12-601.1.htm |publisher=Illinois General Assembly |access-date=2 December 2018 |date=2 July 2003}}</ref>

During emergencies where evacuation of a heavily populated area is required, local authorities may institute [[contraflow lane reversal]], in which all lanes of a road lead away from a danger zone regardless of their original flow. Aside from emergencies, contraflow may also be used to ease traffic congestion during rush hour or at the end of a sports event (where a large number of cars are leaving the venue at the same time). For example, the six lanes of the [[Lincoln Tunnel]] can be changed from three inbound and three outbound to a two/four configuration depending on traffic volume. The Brazilian highways [[Rodovia dos Imigrantes]] and [[Rodovia Anchieta]] connect [[São Paulo]] to the [[Atlantic]] coast. Almost all lanes of both highways are usually reversed during weekends to allow for heavy seaside traffic. The reversibility of the highways requires many additional highway ramps and complicated [[interchange (road)|interchanges]].