Faulty traffic lights statistics

Henry Shrimp made this Freedom of Information request to Kent County Council This request has been closed to new correspondence. Contact us if you think it should be reopened.

The request was successful.

Dear Kent County Council,

How many traffic lights were found to have a faulty red light by Kent Council

Yours faithfully,

Henry Shrimp

Kent County Council

Dear Mr Shrimp
We acknowledge receipt of your request for information relating to faulty
red traffic lights and having looked into your enquiry we can advise that
the County Council does not hold information falling within the scope of
your request.

All of KCC's traffic signal installations are monitored for signal aspect
lamp failure.
Because red lamps are safety critical, as soon as a lamp fails a fault is
registered on our monitoring systems and then raised with our maintenance
contractors (Telent), If one aspect (colour) fails on a single approach
then our maintenance contractors have 24 hours to replace it, if two
aspects fail on a single approach the site will register a higher priority
fault on our monitoring system. The maintenance contractors will have 4
hours to get the site fully functioning.

Since converting to LED signal heads the monitoring of the lamps has
altered. As a traditional halogen bulb is either on (with current flowing
through it) or blown, off (with no current able to flow) it is easy to
test the circuit. It either works or it does not.

With LED heads there are 12 individual LED 'bulbs' in every aspect
(colour), when one LED fails in an aspect the remaining 11 LED 'bulb' get
brighter to compensate. When a second LED 'bulb' fails the remaining 10
brighten again to compensate. When a third LED 'bulb' fails the whole unit
will blow, send a message to the controller and then to us that a whole
aspect is out. The maintenance contractor will then have the allotted
period to replace the lamp. 

Therefore at any given time there are no red lamps out on the KCC road
network (this excludes roads maintained by the Highways Agency) that are
not already scheduled to be replaced with in the allotted time frame.   To
clarify, we do not hold records that identify the colour of faulty traffic

I trust this response is helpful to you but if you have any query with the
information provided please contact me. However, if you are unhappy with
this response, and believe KCC has not complied with legislation, please
ask for a review by following our complaints process; details can be found
at this link
on our website. Please quote reference FOI/11/1734 in any further
correspondence relating to this request.

If you still remain dissatisfied following an internal review, you can
appeal to the Information Commissioner, who oversees compliance with the
Freedom of Information Act 2000. Details of what you need to do, should
you wish to pursue this course of action, are available from the
Information Commissioner’s website

Yours sincerely

Pauline Banks

Kent County Council
BSS GL Information Resilience & Transparency
Sessions House, Rm 2.71
County Hall
Kent. ME14 1XQ
T: 01622 694999
F: 01622 696075

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