yokes on traffic

[Fathertedc]

i am seeing yokes that look like small webcams on top of traffic lights and was wondering what they are ? Are they cameras or sensors or someit else ? They are on the traffic lights where Tolka Rovers play ( Johnny 5 ) and ballymun road meet

 

[davelegacy]

SENSORS..

Usually used on a busy/quiet crossroads........

so the busy side at night stays green until it detects traffic on the quiet side.

 

[Woogy]

Most cameras on traffic lights would be used for what exactly Dave said,or else just to record the traffic on the road.

 

[DUFFMAN]

ya i know them ones,as the lads said