Having travelled frequently up the M42 passed Birmingham over the last few years I've often been stuck in heavy rush hour traffic that is stop-strat all the way from the M40 junction to the M6.

In recent weeks they have introduced a variable speed limit on this section and the difference is amazing. Fair enough you tend to end up at "just" 50mph all the way but on the last 3 journeys I havent stopped once.

Allt his is enforced with speed cameras so epople do actually pay atention to the limits.

Having travelled frequently up the M42 passed Birmingham over the last few years I've often been stuck in heavy rush hour traffic that is stop-strat all the way from the M40 junction to the M6.

In recent weeks they have introduced a variable speed limit on this section and the difference is amazing. Fair enough you tend to end up at "just" 50mph all the way but on the last 3 journeys I havent stopped once.

Allt his is enforced with speed cameras so epople do actually pay atention to the limits.

Having travelled many a miserable mile on the uk motorway network, I'd have to agree the variable speed limit idea, is a good one. Not too fussed about the cameras myself though, but in this instance, they definatley improve the traffic flow.

I think that if people left safe distances and avoided unnecessary braking we wouldn't need them.

Make the test harder and introduce much harsher penalties for driving like a t***!

Just goes to show that it's the siting / purpose of most speed cameras that's the problem, and not the actual concept of them...

All the variable speed limit system does is to bring us all to the same speed as the middle lane owners club (My pet hate) who refuse to move to the correct lane when they have completed their manoeuvre.

If all motorists adpoted the correct lane discipline, nearly all traffic congestion would improve.

Having not actually driven on the M42 when the variable speed limit is enforcing i cannot comment on my personal experince, however it is good to know and having driven past it pretty much every day it does seem to be working and like others have reported it works, at the end of the day its better to do the journey at a constant 50mph than do 70 for a bit and stop for half an hour doing 10mph and so on about time they got one right.

AT the end of next year the M42 "Active traffic managment" system will allow people to use the hard shoulder as a 4th lane at busy times. It'll be interesting to see how well that works.

what happens when someone breaks down? is there some sort of warning or will the lane close in that event?

All the variable speed limit system does is to bring us all to the same speed as the middle lane owners club (My pet hate) who refuse to move to the correct lane when they have completed their manoeuvre.

If all motorists adpoted the correct lane discipline' date=' nearly all traffic congestion would improve.[/quote']

:iagree: How true. If I had a pound for every time I've been flashed for pulling out from Lane 1 to Lane 3, and then going back to Lane 1 after passing the car that's 'stuck' in the middle lane...

What did I do wrong, exactly? Could understand it if there was lots of traffic and I was cutting people up, but not when there's no-one else on the road!?!

Started to see more and more drivers of certain German saloons staying in Lane 3 instead of pulling over...

AT the end of next year the M42 "Active traffic managment" system will allow people to use the hard shoulder as a 4th lane at busy times. It'll be interesting to see how well that works.

Heaven help anyone who gets involved in an accident when all four lanes are in use... Are the Emergency Services mean to join the motorway after the accident and drive back towards the scene, or what? :(

personally think they are a good thing, i've driven down that way a few times when the system wasnt in use and the stop start traffic is a pain in the backside. at times its enough to make me get off the 42 and go through solihull and acocks green to get into the centre of Brum... living in Walsall thats a crap way to have to go.

i agree with everyone thats complained about other road users but at the end of the day your always going to get sub standard t**ts on the road that dont care about anyone else.

If I had a pound for every time I've been flashed for pulling out from Lane 1 to Lane 3' date=' and then going back to Lane 1 after passing the car that's 'stuck' in the middle lane...

[/quote']

I've taken to slowing to their pace in lane1 then wait for them to slow down and I just go right on by...

Not been flashed for 1 to 3 and 3 to 1 with not much room to spare. Some times I'll go round again or clean my windscreen a lot.

Variable speed and fluid dynamics does work, was proven about 10 years ago in the US. I have had problems on it but it's far far better now that the roadworks have gone. The problem now is the lines left behind for the cameras, had a chap changing lanes the other day and he braked half in half out, that crash barrier is mighty large at times and he was well inside the limit anyway.

Had a bm up my bum the other night pushing in 3 lanes of busy traffic...any gaps I was gone anyway, bm had no acceleration nly cling film like abilities...traffic he's up my bum, let him go eventually but he was only a few cars further on...only I find him 40 miles or so later on an empty m-way in lane 3...oh I had some fun and boy did he slow down and when I didn't go past him, he moved over too, but I was quite happy to follow him for a while

3rd lane hog lessons inspired by Duel

TBH, I fail to see how slowing people down reduces congestion - surely the opposite is true?

If numpties joining the motorway are too stupid to use that pedal underneath their right foot to join motorways, instead of piddling up a sliproad at 30 mph, then we wouldnt need this. As usual, another decision to made with the lowest common denominator in mind.

They should be f**king well training people to drive properly. Half the problem is that these numpties are absolutely sh*te drivers. I see it every day in town. Its getting very wearing.

TBH' date=' I fail to see how slowing people down reduces congestion - surely the opposite is true?

[/quote']

There was a programme on a few years ago about this. If you slow traffic down on motorways, traffic density increases (smaller gaps required) and and the overall flow rate actually improves.

Theres a point at which the flow rate reduces if you drop the speed too far, but I seem to remember the optimum flow rate is achieved at around 50 mph.

I've noticed that on occasion, where there is a reduced speed for roadworks, my journey takes less time once people are used to the contraflow. When the roadworks finish, the journey takes longer!

There was a programme on a few years ago about this. If you slow traffic down on motorways' date=' traffic density increases (smaller gaps required) and and the overall flow rate actually improves.

Theres a point at which the flow rate reduces if you drop the speed too far, but I seem to remember the optimum flow rate is achieved at around 50 mph.

I've noticed that on occasion, where there is a reduced speed for roadworks, my journey takes less time once people are used to the contraflow. When the roadworks finish, the journey takes longer![/quote']

That is exactly how it works, the slower traffic goes the more traffic you can fit on the road. A lot of speed limits are done for this purpose, as traffic just keeps growing. Variable speed limits are good, better for cars and the enviroment than stop start driving, and shockwaving but if the cameras weren't there how many would pay attention to the limits?

As for the M42 ATM, what happens it the hard shoulder becoem as running lane in really heavy traffic. As traffic is heavy and people are going at max 50 mph, should someone break down the lane can be closed easilly using the matrix's and there are laybys every 800m or so.

Nothing will ever cure J10 of the M6 or M5 at Bristol

One thing I'll never agree on is that speed cameras are a good thing.

One thing I'll never agree on is that speed cameras are a good thing.

I agree but I dont class these as speed cameras, when roads are congested the variable speed limits are a positive thing & work well, more traffic management I guess.

Beware when driving in Germany, the friendly traffic Gestapo have a habit of putting the temp speed limit signs on when the traffic on the Autobahn is light & then sitting on the bridges with Radar.

It would apear its not just English motorists who get persecuted to raise money or was it just entrapment for the Cannonballers !!

3rd lane hog lessons inspired by Duel

Something else I wondered about now there are Variable Speed Limits on the M42. When congestion is light and it's National Speed Limit, are the cameras set to catch folk doing more than 70?

Something else I wondered about now there are Variable Speed Limits on the M42. When congestion is light and it's National Speed Limit, are the cameras set to catch folk doing more than 70?

I hope so why shouldn't they be?

(waits for backlash for that comment)

I hope so why shouldn't they be?

(waits for backlash for that comment)

Frelling hope not...

For those of you who hate middle lane drivers and like variable speed limits, I have some bad news. As a consultant computer programmer, I've had some exposure to the programs that controlled the variable speed limit on the M25. The more often cars change lanes, the harder it is to accurately monitor the flow of traffic. You might have noticed that there are some signs on the M25 that ask drivers not to change lane excessively.

I think that if people left safe distances and avoided unnecessary braking we wouldn't need them.

Make the test harder and introduce much harsher penalties for driving like a t***!

There are actually programs now, being used in Europe (not here yet I think) which can map and monitor lane usage. So technology exists to book middle-lane hoggers. Now I think this is a much better use of speed-camera money...!