£300m traffic jam busting scheme made journeys longer, Highways England admits

[Micro The Maniac]

And then you have full-time traffic lights at locations where, at most, you would only want peak time control, such as here -

The Queen's Roundabout in Farnborough was one such pinch-point scheme turning a free-flowing roundabout (other than 16:30-18:00 when the business park kicks out) into a 24/7 congestion point.

Most infuriatingly, the sequencing of the lights is such it is virtually impossible to get around the roundabout without having to stop at every set

Not to mention that the 70MPH limit on the dual-carriageway Farnborough Road has been reduced to 50MPH on the approach and 60MPH for the rest......

[trickstat]

And then you have full-time traffic lights at locations where, at most, you would only want peak time control, such as here -

The Queen's Roundabout in Farnborough was one such pinch-point scheme turning a free-flowing roundabout (other than 16:30-18:00 when the business park kicks out) into a 24/7 congestion point.

Most infuriatingly, the sequencing of the lights is such it is virtually impossible to get around the roundabout without having to stop at every set

Not to mention that the 70MPH limit on the dual-carriageway Farnborough Road has been reduced to 50MPH on the approach and 60MPH for the rest......

I recognized this roundabout as I used to regularly go to Rushmoor Arena for sporting events.

[jackal]

The A500 and A50 pinch-point improvements also made queues worse backing down the D Road as they removed the fast link.

By "fast link", do you mean the filter lane from the A500 southbound offslip to the A50? It's probably a lot safer that it's gone. Traffic was only supposed to use that lane if it was taking the first turn off the A50 (for local traffic and the B5490) whereas A50 traffic should have stopped at the lights. However, pretty much all traffic used the filter anyway then moved over, usually without checking mirrors, to rejoin the A50 after the roundabout.

Yes the filter lane. And yes it was used wrongly which I guess caused more shunts but at least the traffic wasn't backed up down the D Road to Bradford like it is most afternoons now.

The road markings actually allowed this movement so I'm not even sure it was 'wrong' to do it. If they wanted to restrict the movement they could have just painted a solid line. 2012 imagery from Google Earth (click to expand):

The other thing is did they really need the massive tiger tail? It created much of the problem by tightening the weaving space. A conventional lane drop might have worked better.

But why think about the problem when you can just slap down some capacity-sapping traffic lights. Hopefully this study is a sign that sentiment might be shifting against this destructive attitude.

[RichardA35]

..But why think about the problem when you can just slap down some capacity-sapping traffic lights. Hopefully this study is a sign that sentiment might be shifting against this destructive attitude.

Perhaps this approach was actually what was wanted to achieve one of the PP programme aims to support economic development by unlocking some capacity for developers to be able to plug their developments into the trunk network. A few seconds lost on a few vehicles would allow all sorts of development opportunities - just saying.
For example - there is a proposed multimodal logistic park development just west of Dartford supported by the Mayor that received an objection from HE that there was no capacity at Dartford crossing to receive any lorry movements from the development. IIRC the HE approach was that LTC had to be built first to free up capacity...

[roadphotos]

I'm surprised nobody has mentioned the so called pinchpoint improvements to the Copdock Interchange at Ipswich which took away the free flow movement from the A14 to the southbound A12. The traffic now queues down the slip road onto the A14 bringing it to a standstill.

[Big L]

Weren't many of the pinch-point schemes justified on the basis of allowing development? Improve a roundabout so you can build 500 homes or a huge retail/business park nearby, and surprise surprise, congestion becomes worse than it was before.

[baroudeur]

The Queen's Roundabout in Farnborough was one such pinch-point scheme turning a free-flowing roundabout (other than 16:30-18:00 when the business park kicks out) into a 24/7 congestion point.

That brings back many memories having been stationed at Blenheim Barracks opposite the Queen's Hotel 1957-1959.

[jedikiah]

Weren't many of the pinch-point schemes justified on the basis of allowing development?

The programme had three objectives:

• Relieve congestion
• Stimulate economic growth
• Improve safety

I guess there could be development within the second criteria but it wasn't the overriding one. It seems the assessment report is based mainly around the first and third.

[Big L]

Have a read of this press release from 2014 and tell me about development not being important criteria.

[Johnathan404]

It feels like every press release I've ever seen from Highways England has cited 'stimulating development' or 'forthcoming development' as the main reason for the works.

I've made the point several times on here before that Highways England had a terrible record of overrunning around the time that the Pinch Point works took place; off the top of my head M27 J5, M3 J6, M3 J2-4a, M6 J11a-13, M60 all went on for around a year after they should have opened. It's not a total surprise that the schemes which were built during this period may have been the product of a terrible planning stage too.

[jedikiah]

Have a read of this press release from 2014 and tell me about development not being important criteria.

My list came straight from the headline description published at the start of the programme in 2011. It depends if economic growth = development, as I said above. Looking at the early schemes there is little to no mention of housing though, and even the growth part is often listed last.

[James]

The A500 and A50 pinch-point improvements also made queues worse backing down the D Road as they removed the fast link.

By "fast link", do you mean the filter lane from the A500 southbound offslip to the A50? It's probably a lot safer that it's gone. Traffic was only supposed to use that lane if it was taking the first turn off the A50 (for local traffic and the B5490) whereas A50 traffic should have stopped at the lights. However, pretty much all traffic used the filter anyway then moved over, usually without checking mirrors, to rejoin the A50 after the roundabout.

Yes the filter lane. And yes it was used wrongly which I guess caused more shunts but at least the traffic wasn't backed up down the D Road to Bradford like it is most afternoons now.

Yet people still use the far left lane for the A50 so it hasn't improved anything apart from making more cars wait for the lights, by keeping mostly right and using lane 3 is the fastest way through the junction, but that seems to be lost on most users of the junction - this is just un-intuitive bad design

The fix is easy, put the freeflow back and have it go into lane 2 and have a regular slip for the stadium, losing the tiger tail lane 1 allowing the slip to be moved further up. I seldom see anything leaving there and the junction causes so many problems for the A50 which should have priority

[JonB2028]

I'm surprised nobody has mentioned the so called pinchpoint improvements to the Copdock Interchange at Ipswich which took away the free flow movement from the A14 to the southbound A12. The traffic now queues down the slip road onto the A14 bringing it to a standstill.

If that was what was done in 2011, that was funded by the Port of Felixstowe and developed separately, along with changes to Dockspur roundabout at Felixstowe.

I thought two lanes were marked and signed for the left turn onto A12, my recollection was people stick to the nearside lane.

[Norfolktolancashire]

The European and American idea of having lights that go in a flashing red for side road and flashing amber for main road at night is a great one. Why the UK insists on making life so difficult to get anything done is beyond me. Most of the traffic light controlled roundabouts around Preston need the lights for a total of probably 1 hour in each rush hour and then they are not warranted or needed at all for the remaining 22 hours of the day, yet then spend 22 hours holding people up for no reason at all. Baffling. I'd also suggest the right (left in UK) on red as a fantastic idea too but anyone who works in H&S will implode at the thought

It seems that the local councils like all new roundabouts and junctions to be traffic light controlled here in Preston, the ongoing improvements of the A582 have the new junctions traffic light controlled, as you say, 24 hours a day. This means that the through traffic is constantly interrupted as the lights do not default to green at night for that traffic flow.

www.google.co.uk/maps/@53.733289,-2.726 ... 312!8i6656

www.google.co.uk/maps/@53.7499145,-2.72 ... 312!8i6656

As for the figure of eight junction lights under Junction 31 of the M6!

www.google.co.uk/maps/@53.7650928,-2.63 ... 312!8i6656

[Ruperts Trooper]

Is there a way of measuring, estimating or calculating the "cost" in terms of CO2/NOx pollution caused by vehicles having to stop unneccessarily at light controlled roundabouts?

[RichardA35]

Is there a way of measuring, estimating or calculating the "cost" in terms of CO2/NOx pollution caused by vehicles having to stop unneccessarily at light controlled roundabouts?

Yes this is done when appraising schemes. Of course the "Do Nothing" scenario might have a worse outcome (think longer queues of slower moving traffic on all approaches) or the scheme would not go ahead.

[Ruperts Trooper]

Is there a way of measuring, estimating or calculating the "cost" in terms of CO2/NOx pollution caused by vehicles having to stop unneccessarily at light controlled roundabouts?

Yes this is done when appraising schemes. Of course the "Do Nothing" scenario might have a worse outcome (think longer queues of slower moving traffic on all approaches) or the scheme would not go ahead.

Perhaps I should have underlined the "unneccessary" - the difference between full-time lights and peak-only lights.

[RichardA35]

Is there a way of measuring, estimating or calculating the "cost" in terms of CO2/NOx pollution caused by vehicles having to stop unneccessarily at light controlled roundabouts?

Yes this is done when appraising schemes. Of course the "Do Nothing" scenario might have a worse outcome (think longer queues of slower moving traffic on all approaches) or the scheme would not go ahead.

Perhaps I should have underlined the "unneccessary" - the difference between full-time lights and peak-only lights.

As has been emphasised here many times previously, once you have optimised the geometry for signals and the queuing capacity at the stop line, this would the become a less safe geometry for vehicles to run at speed without signals.

[Berk]

Yes this is done when appraising schemes. Of course the "Do Nothing" scenario might have a worse outcome (think longer queues of slower moving traffic on all approaches) or the scheme would not go ahead.

Perhaps I should have underlined the "unneccessary" - the difference between full-time lights and peak-only lights.

As has been emphasised here many times previously, once you have optimised the geometry for signals and the queuing capacity at the stop line, this would the become a less safe geometry for vehicles to run at speed without signals.

So the argument moves on from reducing congestion and environmental emissions, to one of traffic management.

Why bother implementing a scheme if it only brings negative outcomes?? It would be better not to spend the money at all, seriously.

Nearly every controlled, signalised junction I’ve had the misfortune to encounter has at least some congestion attributable to the cycle of lights, and naturally sluggish traffic after moving off.

Sometimes the green cycle is so short, as the queue moves off so slowly that only half of it manages to move away from the roundabout.

Looking at the examples from Preston there, that was obviously designed as an urban link road, whether as 50, 60 or NSL. It was also designed to be free-flowing with roundabouts. It at least one of the shots, the roundabout was replaced with a signalised T-junction.

I just cannot comprehend why, when all it will do is add to queueing, stationary traffic, and more vehicle emissions, and added CO2 from the lights themselves.

[Johnathan404]

Why bother implementing a scheme if it only brings negative outcomes?? It would be better not to spend the money at all, seriously.

I don't think there are many schemes which have "only brought negative outcomes". You might not value the positives - generally reduced queueing on certain arms during peak periods - but to write them off completely is unhelpful.