Driving standards

[Reorte]

8 minutes ago, SM42 said:

In fact it's not even a give way line at the bottom of a slip road, just a lane divider

 

That's why you indicate right to join the motorway rather than left.

[SM42]

28 minutes ago, kevinlms said:

A system of rearranging slip road traffic has been around for a while, certainly fairly common in NZ & Australia.

You might think that they wouldn't work, but surprisingly they do work rather well.

 

This instruction video is from Queensland, note the bus lane to bypass the queue, in Victoria they use it for trucks too.

 

 

Doesn't work too well in the UK. The lights bunch up the joiming  traffic so a  a glut of 5 or 6 vehicles try to fight their way in all at once and much application of brakes and resultant queues.

 

Andy

[caradoc]

Last week I shared, with my daughter, the driving of a large vehicle more than 800 miles, on the M77, M8, M73, M74, M6, M6 Toll, M42, M40, plus non-motorway roads, and can't say I found it particularly stressful, not even the 20 miles at 50 mph  in narrow lanes for 'Smart' motorway works on the M6 through Staffordshire. I do share the misgivings about Smart motorways however; It was noticeable on the M42 that where the former hard shoulder was open as a traffic lane, not that many vehicles actually used it ! And I was surprised, on the M6, just how few emergency refuges there will be, and how far apart they are. 

 

[kevinlms]

12 minutes ago, SM42 said:

 

Doesn't work too well in the UK. The lights bunch up the joining  traffic so a  a glut of 5 or 6 vehicles try to fight their way in all at once and much application of brakes and resultant queues.

 

Andy

But only one vehicle is supposed to go through on the green. Which in your example, means 4 or 5 are jumping the red light.

No wonder the system doesn't work!

[SM42]

1 minute ago, kevinlms said:

But only one vehicle is supposed to go through on the green. Which in your example, means 4 or 5 are jumping the red light.

No wonder the system doesn't work!

 

No just longer green phases, otherwise the traffic on the approach roads would be gridlocked.

 

Andy

[kevinlms]

1 minute ago, SM42 said:

 

No just longer green phases, otherwise the traffic on the approach roads would be gridlocked.

 

Andy

Certainly not how ours works. If they need to increase the flow, then they make the time between greens shorter, but I've NEVER seen longer green sequences.

If it gets blocked on the approach roads, then it's too bad, the principle is to keep the freeway moving and you can't do that by flooding it with a bunch of vehicles.

Not saying our system works 100% of the time, it certainly doesn't.

[Joseph_Pestell]

1 hour ago, Nick C said:

 

One of the worst for that round here is the slip from the A34 onto the A303 eastbound - a 90 degree corner immediately prior to a very short slip (no room to extend it due to the bridge taking the one road over the other) resulting in a slow start, no advance visibility, and very little room to accellerate. I always try to make sure I'm in lane two as I approach on the 303 if I can, to allow anyone coming up room to pull out. 

 

Total joke of a junction given that it connects two such busy roads.

 

Going from the A303 onto the A34 north is no better.

[Reorte]

17 minutes ago, kevinlms said:

Certainly not how ours works. If they need to increase the flow, then they make the time between greens shorter, but I've NEVER seen longer green sequences.

If it gets blocked on the approach roads, then it's too bad, the principle is to keep the freeway moving and you can't do that by flooding it with a bunch of vehicles.

Not saying our system works 100% of the time, it certainly doesn't.

Not much point in just moving queues of traffic around, which is what happened when they first tried it around here (it's been adjusted a bit since).

 

I'm not really keen at all on the idea of using traffic lights for this sort of purpose because I feel it dilutes the message of a red light somewhat - you must stop because it's dangerous not to due the high probability of coming in to contact with a vehicle or person who's been given a green, which is why (most) people get so annoyed with red light jumpers.

[petethemole]

Total joke of a junction given that it connects two such busy roads.

 

Going from the A303 onto the A34 north is no better.

 

I remember that when it was just a crossroads, wilth a pub on one corner.

Edited September 24, 2020 by petethemole

[Mark Saunders]

Even worse are the number of large roundabouts with no lane guidance and the confusion it causes!

[34theletterbetweenB&D]

Quite a few junctions like that lurking around the road network, which if you happen on them without local knowledge are awkward at best. The worst of the original slip roads on the M1 were happily eradicated when the carriageway widenings for more lanes were undertaken. These had clearly been designed for joining speeds around the 40mph mark, back in the day when that was terminal velocity for commercial vehicles and Morris Minors.

23 minutes ago, kevinlms said:

...If it gets blocked on the approach roads, then it's too bad, the principle is to keep the freeway moving and you can't do that by flooding it with a bunch of vehicles.

Not saying our system works 100% of the time, it certainly doesn't.

UK traffic densities are typically much greater. Block an approach road to the Motorway (= Freeway) and that backs up around that junction to all the on and off slip roads in no time, and the Motorway is seriously slowed or stopped in one or both directions: caused by all the vehicles leaving the motorway at that junction crawling or stopping on the motorway, because the whole exit junction is choked and barely moving.

 

The traffic flow monitoring for London is very informative. A stopped major junction in central London, if not cleared rapidly, backs up to the M25 (at an average distance 20 miles out from the centre) and brings it to a standstill in between 22 to 25 minutes. In other words the blockage travels at 30 - 40mph through the road network. The regulation is a very delicate 'dance' to keep everything moving wherever possible - even at reduced speed - to limit the number of incidents where there is no movement for a minute or more. After a minute, it will be multiple junctions blocked, and then the trouble really kicks off. I was unable to leave my home town one famous evening due to a major accident on London's North circular, 18 miles away. It took some local knowledge to achieve the half mile trip home, as many drivers were trying the residential roads to get around the blockage

[SM42]

Just a minor change or incident can have major ramifications with UK traffic flows.

 

Within a stonesthrow of SM42 Towers there is roundabout. It is on a relatively busy main route into town. Traffic builds up at peak times but no more than 5 or 6 minutes delay.

 

At the next roundabout traffic queues were bigger as most drivers took a route off that roundabout towards a set of traffic light around 1/2 mile distant and things regulary backed up in evening rush hour

 

A few years ago the council built a new road to create a short cut, thus "reducing congestion." So now you cross the first roundabout and turn left to miss out the second. However they decided to install traffic light at the new junction despite many living locally saying that the same anount of traffic will still be heading that way and just get stopped sooner at the lights and cause a back up to the first roundabout. 

 

Why can't we have a another roundabout that self regulates now that the traffic flow will be split between the left turners and the straight onners. It will flow better all round

 

"Oh not at all" said the council, "lights will be fine" totally ignoring the lesson from around 20 years ago when a new set of lights 2 miles away caused gridlock on the first day and still cause 3 mile queues now at rush hour after being "adjusted".

 

So now the traffic backs up on the first roundabout every time the new lights turn red and it's a nightmare at most times of the day.

 

The council blame traffic levels (that haven't really changed) and now are spending a fortune looking at some other solution, but they won't tell anyone what it is, except it's not a roundabout to replace the lights or more traffic lights.

 

In terms of fun slip roads, I find the M50 to be right up there amongst the best

 

Andy

 

I forgot to mention, their first attempt to solve the probelm was to re-open the right hand lane that they closed when they installed the new junction.

We now have regular drag races off the new lights for the 200yds before it reduces back to one lane

 

Edited September 24, 2020 by SM42

[kevinlms]

1 hour ago, 34theletterbetweenB&D said:

Quite a few junctions like that lurking around the road network, which if you happen on them without local knowledge are awkward at best. The worst of the original slip roads on the M1 were happily eradicated when the carriageway widenings for more lanes were undertaken. These had clearly been designed for joining speeds around the 40mph mark, back in the day when that was terminal velocity for commercial vehicles and Morris Minors.

UK traffic densities are typically much greater. Block an approach road to the Motorway (= Freeway) and that backs up around that junction to all the on and off slip roads in no time, and the Motorway is seriously slowed or stopped in one or both directions: caused by all the vehicles leaving the motorway at that junction crawling or stopping on the motorway, because the whole exit junction is choked and barely moving.

 

The traffic flow monitoring for London is very informative. A stopped major junction in central London, if not cleared rapidly, backs up to the M25 (at an average distance 20 miles out from the centre) and brings it to a standstill in between 22 to 25 minutes. In other words the blockage travels at 30 - 40mph through the road network. The regulation is a very delicate 'dance' to keep everything moving wherever possible - even at reduced speed - to limit the number of incidents where there is no movement for a minute or more. After a minute, it will be multiple junctions blocked, and then the trouble really kicks off. I was unable to leave my home town one famous evening due to a major accident on London's North circular, 18 miles away. It took some local knowledge to achieve the half mile trip home, as many drivers were trying the residential roads to get around the blockage

Don't make the assumption that there is no problem with traffic flows in Australia. There most certainly is. It is not all wide open spaces with nothing to see!

The Monash in Melbourne is notorious in peak hour, as it's a suburban freeway and toll road.

[34theletterbetweenB&D]

1 minute ago, kevinlms said:

Don't make the assumption that there is no problem with traffic flows in Australia. There most certainly is...

Understood. You wouldn't have traffic management schemes otherwise.

[ejstubbs]

On 24/09/2020 at 10:52, Compound2632 said:

there's the black Audi accelerating down the slip road intent on swinging straight into lane 2 or 3.

 

Observed on the Edinburgh City Bypass this afternoon: smallish blue hatchback thing did exactly that, into a gap between two cars in lane 2 that I'd swear was no more than three - OK maybe four - car lengths.  Traffic was moving at ~40-50mph at the time.  Let's be generous and say that the gap was 24m long and he moved in to the middle of it, so he had maybe a 10m gap before and behind his car.  40mph is 17.88m/s.  So much for the two-second rule...

 

It got worse.  Approaching his exit, from lane 2 he dived straight across lane 1 on to the slip road - passing between two vehicles in lane 1 again no more than 4 car lengths apart (which was still too close at the speed traffic was moving in lane 1 - but all the more reason not to go there IMO).  And yet both ahead of and behind those two vehicles driving in a somewhat inconvenient mini-convoy there was a yawning gap in lane 1 a least 100 metres long (because, as previously noted, everyone knows the deleterious physiological impact of driving in lane 1 - though fortunately I seem to be impervious to it as I was the one 100 metres back driving in lane 1 myself at the time ).

Edited October 29, 2020 by ejstubbs

[62613]

47 minutes ago, ejstubbs said:

 

Observed on the Edinburgh City Bypass this afternoon: smallish blue hatchback thing did exactly that, into a gap between two cars in lane 2 that I'd swear was no more than three - OK maybe four - car lengths.  Traffic was moving at ~40-50mph at the time.  Let's be generous and say that the gap was 24m long and he moved in to the middle of it, so he had maybe a 10m gap before and behind his car.  40mph is 17.88m/s.  So much for the two-second rule...

 

It got worse.  Approaching his exit, from lane 2 he dived straight across lane 1 on to the slip road - passing between two vehicles in lane 1 again no more than 4 car lengths apart (which was still too close at the speed traffic was moving in lane 1 - but all the more reason ot to there IMO).  Behind the second of those two vehicles was a yawning gap in lane 1 a least 100 metres long...

 

To be honest, that sort of thing doesn't seem to be as prevalent as it was say, 25 years ago, when it was quite common.

 

[ejstubbs]

[Deleted - repeat posting due to the forum software appearing not to register the "Submit" or "Save" buttons being clicked the first time ]

Edited September 24, 2020 by ejstubbs

[johnofwessex]

I understand that when the Dutch rebuilt & expanded their cycle network in the 70's/80's they also rebuilt almost all of their road junctions tio standard layouts so that you didnt get some of the horrors that the UK has.

 

I cant see why like railways, highway work has to be approved by a competent person as safe

[PhilJ W]

I've driven around the M25 in lane one and most of the time I have the lane to myself.

[Adam88]

9 hours ago, SM42 said:

Just a minor change or incident can have major ramifications with UK traffic flows.

 

This often happens with systems which are highly optimised.  They are sometimes described as brittle.  In a similar vein I can be on a main road in the country and get caught behind a tractor and trailer bumbling along at 20 or 25MPH.  How I might curse.  On the other hand there must be many motorists caught in their local stop-start urban traffic who would be only too grateful to be going as fast as 20MPH.

[laurenceb]

Large yellow bus with headlamps on.

https://www.derbytelegraph.co.uk/burton/bmw-driver-arrested-after-crash-4544869

[Compound2632]

17 hours ago, Adam88 said:

 

In a similar vein I can be on a main road in the country and get caught behind a tractor and trailer bumbling along at 20 or 25MPH.  How I might curse.  On the other hand there must be many motorists caught in their local stop-start urban traffic who would be only too grateful to be going as fast as 20MPH.

 

Yes, but you're probably travelling at lest 20 miles, probably more; they're only travelling 5 miles. So it makes a bigger difference to you.

[johnofwessex]

More to the point the massive amount of mud many farmers leave on the road, which is a criminal offence and farmers have gone to jail for

[TheQ]

You mean there is something under the mud outside,  ?

Actually with a month's worth of rain over Friday and into Saturday,  it's washed the roads pretty well, so. We'll see the tarmac till the next harvesting or ploughing.. Sugar beet next I think.. 

[peanuts]

oh dear !

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