Filtered Traffic Lights

So following on from the previous post, I said that we would have a look at filtered traffic lights and as usual there are a few different combinations. Here is the first example:

With this one it is fairly obvious that the left pair of lights control the left 2 lanes and the right 2 control the right turning traffic. So in the current state of this picture the traffic turning right have a red light, whereas those going straight ahead have green. But sometimes it is not quite as clear as this, here is another example (sorry picture isn't perfect).

The lanes shown by the green and blue arrows are controlled by the lights shown by the red arrow. I've inserted a larger version into the picture to help you to see what's going on. So if you are travelling in the "blue" lane, intending to turn right - you must obey the RED light. However as the light sequences progresses you will see a green light in the shape of a right facing arrow. When this happens, you need to turn right, safe in the knowledge that the on-coming traffic will have a red light i.e. you don't wait.

The next picture shows a few of typical filter lights, but there are many types.

The junction in the image below is in Lichfield and has what I call a "part-time filter light". Looking at the above picture, the right hand light has a normal green light plus a right facing arrow green light. This is what is we have in the picture below (shown by white arrow).

As you approach this one, the lights will change (at some point) and traffic going left, ahead and right will have a green (circular) light. So if you are turning right, you will position yourself ready to turn - waiting for on-coming traffic. However after a few seconds the bottom fourth light (green arrow) might come on and you can proceed (as above you can be sure that the on-coming have red light). But filter light doesn't always come on; the sensors try to check if there is any vehicle waiting to turn (hence my name - part-time).

So lots of different filtered traffic light complexes to deal with and if you want to learn to drive in Tamworth or Lichfield please click the appropriate link.