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‘Secondary’ Traffic Lights



Every Traffic Light has a ‘Stop Line’ and at least 2 signal heads.  You must stop before the Stop Line.  The reasons there are always at least 2 signal heads is


·        If one light breaks then there needs to be a spare.

·        You must always be able to see a signal head whether you are approaching the light, or waiting at the ‘stop’ line.


For these reasons, in addition to the Primary light, there will always be at least one ‘secondary’ light.  At pedestrian crossings you will often see a ‘closely associated secondary’.  At many junctions you will see ‘distance secondary’ lights.  In my opinion there are far too many examples where there is a multitude of secondary lights when fewer or just one would do.  And there are badly designed junctions where the secondary light is far away from the stop line even though it would be possible to place it much closer (King William junction in St Albans).



How to Deal with Secondary Lights

First of all, when you see a set of Traffic Lights make sure you look out for the Stop Line beside the Primary light.  This is particualarly important at complicated junctions where there are several different sets of Traffic Lights, each with their own Stop Line and possibly with many 'secondary' lights as well.


Be ready to stop before the line.


Once you have passed over the Stop Line you should be prepared to keep going and clear the junction.  So if your 'secondary' light changes to amber / red you should keep going.


When you turn right or left at a junction, you will often immediately come across a red light.  This is normally not for you.  This is normally the 'secondary' light for the traffic coming from the other entrance to the junction.  If the light is for you (if for example there is a Pelican Crossing very close to the junction), then there will be a Stop Line by the red light.  'Secondary' traffic lights do not have that Stop Line.



You should not stop at a 'secondary' light.  If you do this on your driving test you will be given a serious fault.  Unfortuanately this is a common fault with new or inexperienced drivers (particularly under the pressure of the driving test).  It is also common amongst people who have come to the UK from other countries.  In their own country they have never seen a 'secondary' light so the concept is totally alien to them.


In an attempt to make thing safer, the agencies who design and build our roads actually make things much more dangerous by covering some lights with 'slats'  (a bit like on a venetian blind), which mean the lights can not be seen from certain directions.  These are normally put over the green and amber lights, which means that you can't see those lights as clearly as you should.  This can be very dangerous, particularly at a complicated, fast junction with many sets of 'secondary' lights which are clearly visible.  You can be concentrating so much on the complicated junction, the heavy traffic and 'secondary' light  -  so you may not realise, or will realise far too late, that you have just zoomed past a 'primary' light which has just changed to RED!


A Solution

In France and Spain (and possibly many other places as well), they don't have 'secondary' lights.  Instead they have a very small set of lights at about shoulder height on the same pole as for the 'primary' light.  This means that the 1st car in the queue, or a cyclist, can see the light change to green.  A simple solution which completely does away with the need for the multitude of confusing and dangerous 'secondary' lights.  Why we don't adopt the same convention in the UK is beyond me.


‘Secondary' lights should be placed as close to the primary light as possible, and before entering the junction.  But they are not always, so you will have to concentrate carefully while you get used to the strange ways our roads are designed.


In the exceptional cases where a 'secondary' light on the far side of the junction in unavoidable, then this should be given a different colour pole, slightly different size and shape, and a background plate in a distinctive colour  -  all of which makes it perfectly clear to the driver that he is facing a 'secondary' light.  Slats on these secondary lights would be another way of making the difference clear and it would ensure they can only be seen by those vehicles who need to see them.