Doesn't traffic flow increase at lower speeds because vehicles follow closer?

Bottlenecks/pinch-points are a great British passtime. When I go on holiday to the West Country, I endure the wonder one at the junction of the M4 and M5 near Bristol.

The M25 QE bridge was built only for one direction and closes when its really windy, leaving only the old tunnels (normally for the anti-clockwise only) with two lanes each way. No spare capacity and no hard shoulders in the tunnels for emergency access, other than shutting down the other tunnel and going across on foot.

The A1 reducing from three to two lanes at several points between the M25 and Letchworth Garden City, including around Stevenage (absolutely class), though at least these sections do have a hard shoulder. Oddly enough, on another stretch of road (dual carriageway) near me, most serious accidents (and there are many) occur just after speed cameras.

Too many to bother saying for the railways. Apparently the UK has more CCTV and speed cameras per person than almost anwhere in the world.

We Brits love inventing problems to solve in a very expensive way.

The problem with the tunnel is that especially westbound there is a long downhill which bends as you approach the bottleneck, plus there will inevitably be late lane changers eager to jump the queue as such forcing in from the left hand lane at the last minute, all this adds up to speeds having to be restricted or you will have 44 tonners going down there fully laden at 55mph and last minute Fred will amble across in front of one of them and die instead of gaining that 20 vehicle spaces he intended.

And yes i know that bods in container carrying lorries are some of the worst queue jumpers out there and yes other lorry drivers dislike their poor driving as much as car drivers do.

I'm afraid this is what we will all have to put up with in the coming years, the population has been deliberately increased by successive governments in order to make it look like they are managing economic growth, but no one thought about infrastructure.

That complete mess of an junction at the other end of Newport m4/A48/A467 is just as bad, i use the A467 quite often and i wonder just how many people have come off the M4 westbound and due to the new road layout and its hopeless signing have ended up going back on the M4 west, its just as bad coming down the 467 to turn left onto the M4 east, they've made a huge junction but failed to put a filter left in place, so everyone has to stop.

But then when you look at the complete mayhem which surrounds Crumlin when the annual cycle race is on with the entire town cut off for the day, what else did anyone expect.

I suspect it will come to the point when another motorway around Newport will have to be built, whatever the cost, i get the feeling ( but haven't seen figures) that the whole section is busier since the Severn Tolls were removed.

We've got it in Northamptonshire just the same, every spare patch of green land where the very rich don't live is being built on, there are thousands of identical houses going up over the entire, not forgetting the must have huge warehouses stuffed to the rafters with either Chinese tat or food and new shopping centres...all this extra traffic having to use the same roads that couldn't cope 30 years ago.

This is going on all over the country (apart from The Cotswolds eh Dave?) every road you drive down there are houses being built on green land....look you've just passed The Meadows, well yes it was meadows for the last thousand years until you concreted over it!

Country is full, if you think its bad now have a look again in 20 years time when another 10 million people will be crammed onto the island at present levels, and that's if the UN don't impose their extra immigration plans on us via the UN pact for migration signed last year by our pointless leaders without even a by your leave.

I forgot to add earlier that many traffic jams emerge because people drive too close to one another and lane jump, especially by pushing in without warning. That, and rubbernecking and not paying attention to their side of the road or lane.

I find that people tend to speed up to quickly and then have to brake more shaprly at the next holdup, making the situation worse. Doing so more gradually, especially when you can see there's a hold up ahead, is, in my view, far safer and leads to less bunching.

The variable speed limits on motorways would work better if they were more up-to-date and people then adhered to them as well as giving eachother room, including enough to just back off on the accelerator rather than jam the brakes on.

Is there any evidence that congestion or pollution charges have any significant effect. Has solution gone down, is there any less congestion?

There is an argument that creating congestion and making journeys take longer is the best way to dissuade people using their cars.

Road management in the UK seems to be a policy of making life difficult. Every so called 'improvement' in my area has resulted in overnight additional congestion, which every commuter predicted.

So I can only assume its at the core of council/state mentality - motorists must be punished, roads should not be logical and efficient.

Now it seems to me the best solution would be to increase the speed of flow not decrease

to get though the bottle neck. This was born out I think when just average speed cameras were employed when they were putting the present system in. The motorway around Newport seemed to flow much better.

The average speed cameras were presumably set to 50. That seems to be an optimal speed for shifting volume of traffic smoothly.

M1 J16 to 19 is now all lane running 'smart motorway'. Before the work to do that started it was notorious for stop/start queuing without any apparent cause. As soon as the temporary 50 went in it ran much better. Cause of bunching weaving, heavy breaking etc in heavy traffic was mix of speeds from LGVs limited to 56 or less through to rep-mobiles trying to maintain 85.