Traffic Signal

A Traffic Light (or traffic signal) is an electronic device positioned at a road intersection or pedestrian crossing that regulates the flow of traffic through the intersection or at the crossing by variously displaying to motorists and pedestrians either; a red, amber or green light (or symbol), indicating which vehicles and/or pedestrians have right of way at a particular point in time.



The sign below is a traffic light advanced warning sign.


Useful Life

The useful life of traffic signals will vary considerably due to a range of environmental & other factors. A useful life of 25 years appears to be typical for the traffic signals operated or investigated by the organisations listed below.

Please feel free to improve the table by adding your Council or organisation's information.

Asset Owner Adopted Life
Austroads 2 15 years
South Dakota 40 years
MoDOT 3 10 years

Related Pages


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External Links & References

  1. Wikipedia
  2. Google Search
  3. Road Safety Engineering Risk Assessment Part 4: Treatment Life for Road Safety Measures
  4. Life Expectancy and Replacement Schedule for LED Traffic Signals
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