Traffic Lights

Traffic lights are signaling devices located at road intersections and pedestrian crossings, they are now part of our everyday life. Before traffic lights were invented, policeman would control traffic, but accidents would still occur frequently. This is when J.P Knight took action in 1868 and made the first traffic light. It was installed outside the British Houses Of Parliament but didn’t last long since it exploded in 1869 due to a gas leak. It was only in 1912 that a man named Lester Wire created an electrical traffic light that is still used today. There are three main types of traffic lights: fixed timed, semi actuated and fully actuated. Fixed time traffic light are light where “signals change according to a pre-set timing. The signals will cycle all the time even if there is no vehicle or pedestrian demand.” (a). In semi actuated signals vehicle detectors and push buttons are installed on streets and roads. The traffic signals will remain green until either a group of vehicles is detected or a pedestrian pushes a button. Lastly in fully actuated lights “ signals are programmed to change with minimum green times depending on the traffic and pedestrian demand on all approaches. The signals will change based on the demand from each approach.” (b).

Traffic lights were only starting to be used in not only urban regions but also rural regions in only 1975. This graph shows the number of serious accidents from 1980 to 2012. As you can see the number of accidents has decreased. This is due to the fact that traffic lights were used seriously.

Before any type of traffic lights were invented, car circulation would be unquestionably crazy. Car accidents would often happen; pedestrians and car drivers would die. City d...

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...E] Available at: http://www.london.gov.uk/mayor/economic_unit/docs/traffic-signals.pdf.html. [Accessed 29 November 13].

In-text references:

11. (a), (b) Halton Region. 2012. How Traffic Signals Work. [ONLINE] Available at: http://www.halton.ca/cms/One.aspx?pageId=78249. [Accessed 30 November 13].

12. (c). Hanks. P. 2000. The Basics of Loop Vehicle Detection. [ONLINE] Available at: http://www.marshproducts.com/pdf/Inductive%20Loop%20Write%20up.pdf.html. [Accessed 01 December 13].

13. (d) Johns. S. 2011. Traffic Signal Information Traffic Signal History. [ONLINE] Available at: http://www.mctraffic.org/signal.html. [Accessed 01 December 13].

14. (e) Hopkins. K. 2011. City officials discuss pros and cons of new traffic lights. [ONLINE] Available at: http://www.wvec.com/my-city/norfolk/Hampton-Roads-traffic-lights-go-green-130729983.html. [Accessed 01 December 13].