Safe Speed Forums

That is due to traffic is not flowing in the direction the right turn you are making.

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Steve

But I thought your speed humps did that!

Some traffic lights change too damned quickly .... I have couple of sets on my daily commute which only let one car through before they change again. Hence ... lot of cars run them on red. So far .. this has not caused an accident but there have been a lot of near misses .. A more appropropriate time setting would reduce the bottle neck in this area.

Another member of this family reports a set on East Lancs (A580) road (in between Leigh roundabout and and M6 Warrington exit.) Apparently this set of lights on a T-junction 70 mph road on a has a red light camera and only allows on car at a time to get through the lights East-bound (the road is a left turn for East bound traffic. Despite the red light cam ... lot of accidents occur here. Perhaps a longer green flow - given this is a very fast road - would be appropriate....

Would either self or Wildy run a red light?

Only time I have has been on a medic's green light with a police escort.

So far in personal motoring ... we have never been in that position - and both of us have been driving cars for a long time now. But let's just say ... it would depend on circumstances and safety margins (from potential tailgating and quick light change green-amber-red point of view).

There should not be any traffic lights in 60 or 70 mph zones. Ever. I don't know if this is in the rules anywhere or not, but we used to be very good at ensuring that traffic lights were only in 30s and 40s.

It's no good having a different length amber because drivers HAVE to be able to judge the length of the amber when making a stop / go decision.

UK amber is *always* 3 seconds, and 3 seconds isn't enough at 60mph.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

I think we have discussed this before, but in Cheshire there are plenty of traffic lights at junctions of NSL 60 and 70 mph roads (e.g. A49/A533, A540/A550, A34/A537 etc) and most have them have been there for as long as I can remember. It's not a recent phenomenon.

I am not aware that these pose a significant safety problem or have a bad accident rate - if they did, the layout would have been changed. In many cases site constraints would make it difficult to replace them with a roundabout, let alone a grade-separated junction.

If it was to become a rule that there could be no traffic lights in NSL zones all that would happen is that 40 or 50 mph limits would be imposed for 400 yards in each direction, at considerable expense and zero point.

Any sensible driver knows that if you're approaching a set of lights on an NSL road which are showing green, you back off just a little, particularly if you haven't seen them change to green.

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

Yes, you're right, and thanks for reminding me. Nowhere that I've ever lived has had traffic lights on 60 or 70 roads.

If we do calculations on the approach speed of a green light in unknown condition (i.e. we haven't just see it change to green), and allow ourselves 0.75 seconds of reaction time and 0.45g (i.e. half effort) braking, then the maximum safe approach speed is 44mph. See figure 6 on page:

http://www.safespeed.org.uk/braking.html

Note the point (3, 44) on the line.

If we are able to get away with trafic light systems on 60 and 70mph zones, I don't really know how we do it. If I was a traffic engineer "forced" to install traffic lights in a 60mph zone I would insist on a 2 second all-red phase, and I wouldn't accept that we could use a red light camera.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

I think they are particularly prevalent in the North-West. The prime example must be the A580 East Lancs Road referred to above, which has at least 10 signal-controlled crossings in its 70 mph section, and which is a near-straight road which some drivers do treat as "a bit of a racetrack".

I think it may now be officially recommended that traffic lights are not designed in to new NSL roads (not that many of such are built anyway )


I think it's the phenomenon we've remarked on before of a bit of give-and-take making the best of a solution that falls some way short of the ideal.

And I would say a signal-controlled crossroads between two NSL A-roads is in practice likely to be much safer than a totally uncontrolled crossroads where one road has priority, given comparable traffic volumes.

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

I've raised the question of signals on NSL roads on the SABRE roads forum, which resulted in this thread which you may find interesting, particularly message #8 from a professional highway engineer.

Provided drivers act sensibly and don't put the hammer down when approaching a green light I really don't see that they represent a safety problem.

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

A64 York bypass had two sets in the NSL dual carriageway. Both have now been removed.

Worse than that, the M606 now terminates at a set of traffic lights, just beyond a slight crest.

Aren't there slip roads on to motorways with traffic lights somewhere - to reduce allowed traffic merging? Or am I thinking of abroad and telly? Never (knowingly) negotiated any myself I hasten to add.

There are traffic lights at some of the M6 junctions in the West Midlands to control access on to the motorway - however these are probably at locations where the non-motorway road is only a 30 or 40.

_________________
"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed