Safe Speed Forums

On approaching a motorway, you should "check the traffic on the motorway and adjust your speed to fit safely into the traffic flow in the left-hand lane"

It therefore follows that slip roads should be sufficiently long to allow a vehicle approaching the motorway to accelerate to at least 60mph. As the average speed of traffic on motorways has risen over time, it is increasingly important that slip roads are designed to meet this requirement.

There are two recently constructed junctions I use regularly which are not designed with this in mind.

Joining the m6 toll from the A5/A38 island is via the inside loop of a trumpet type junction. Visibility is limited, and the radius of the road is so small that it is necessary to accelerate from a low speed over the short slip road provided. I would estimate thet many ordinary cars would be unable to reach 70mph before joining the motorway at this point. This if anything is well below the average traffic speed on the M6 Toll.

Junction 10 on the M40 is a complete disaster. The recent rebuilding has not helped traffic flow, and two well designed, long slip roads have been replaced by tightly curved ones with the same problems as the m6 toll.

Neither of these junctions appear to have any constraints preventing land use, so it appears that safety is being compromised either as a result of bad design practice or cost-cutting.

Appears to be a road builder's sport...

Take a peak at this site...

http://www.cbrd.co.uk/badjunctions/


All the nightmares are there.

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I remember exiting from a service station on a recent trip down the M6 and it had a trumpet style slip road that was utterly way too short. However, as a daily user of M6 J34 (Lancaster, where you are given about 50 yards to merge and it's impossible to be going fast enough) for half a year, I'm reasonably confident with merging. It's still not a pleasant thing to do in a short amount of space though - amazing how easy it all is when you have time to observe the carriageway you're joining before you have to join it.

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-mike[F]
Caught in the rush of the crowd, lost in a wall of sound..

J34 ...definitely unpleasant.

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If you want to get to heaven - you have to raise a little hell!

Smilies are contagious
They are just like the flu
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Now Good Causes are smiling too!

KEEP SMILING
It makes folk wonder just what you REALLY got up to last night!

Smily to penny.. penny to pound
safespeed prospers-smiles all round! !
But the real message? SMILE.. GO ON ! DO IT! and the world will smile with you!
Enjoy life! You only have the one bite at it.

I think it's the fact that you're faced with the choice of "merge, or drive into the Lune" that makes it quite so nasty...!

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-mike[F]
Caught in the rush of the crowd, lost in a wall of sound..

If you want a really bad junction, even worse then the Lancaster one(which is bad!) then take a look at Junction 12 on the M60, especially the movement from the M602 westbound to the M60 northbound. Not only do you come round and over the M60 on a very tight curve but you are then thrown into the thick of the action at a very bad angle and with a VERY short slip. Speed is not the problem, you could reach 70 without too much fuss, but you have so little time to react that causes the difficulties. The problem is exaccebated by too other problems. Number 1 is that the traffic in the nearside lane is reluctant/unable to move to L2 as its often busy, and that there is a junction just ahead and they want to come of there. The second reason is the merging just ahead(but before the next off slip) of the M62 eastbound. So you've got a lot of cars all jockying for position and your try to join! I'm suprised their isn't more accidents with people slamming on as there is no space and the car behind checking their mirror as visability on the approach is awful.

One entrance on to the M58 at Junction 5 is a Give Way, not a merge

The only time I've ever used it I nearly ended up sideswiping a BMW

This must be about the weirdest junction on the motorway network.

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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 had a funny, almost catastrophic occurance when approaching the Blackwall tunnel (From South to North)

Coming down the slope of the last junction before the tunnel, in the driving lane, with a slip road joining on at the foot of the slope -one bloke in a Focus is about to join, about 30mph (Which is the speed limit, and I know he can't break it because there's one of our yellow friends on the sidewalk. I wanted to stay in the drive lane (left lane) because that's the wider of the two tunnel lanes.

I had two options, accelerate out of his way then emergency brake for the GATSO, but the slip road is short, and he may cut across me. The other option was to move over, but I would be forced to sustain 30 and by the time I clear the GATSO - I have double white lines and big blue signs saying "stay in lane" - and have to suffer the narrow lane in the bendy tunnel. So I come off the gas completely and I am in the range 25mph - but the Focus doesn't like the gap I am leaving and starts to brake. With his slip road coming to an end, I'm forced to slow down more but he still won't get the message - I'm flashing, honking, waving - no dice

In the end - right as he run out of slip road and was about to physically push me to the right - I budged over, annoying the overtakers, but perhaps doing them a favour at the same time

I blame the st00pid GATSO!

Moral of the story I think, is put GATSOs before slip roads to slow traffic and give joiners a chance - and also, for other situations - it's NOT ok to join an NSL M-way at 35mph, especially with a 56mph trucks and 70mph cars roaring up behind you

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Don't you just hate people who do that - especially when they're in front of you?
Don't they realise that, besides the danger they create, they'd probably use less fuel by accelerating up to speed on the slip road - which is almost always a downhill so you have gravity helping you - than by crawling onto the motorway before accelerating to speed?

Cheers
Peter

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Ah.. the Worsley/Eccles interchange... always featuring on local traffic news - and you really have to drive this one to realise just how nasty it really is. I'd say one of the busiest stretches of the M60 given the merges with M602 and M62 and if you join at M13 heading to Trafford Centre or MIA - those entereing have a very short space in which to move to L3 for the straight on - else end up on either the M62 for 10 miles to next exit or M602 for 3 miles...to a congested Eccles town centre.

Not to mention the tight curve which throws HGS entereing the M62 and the clockwise J12/J13 as Capri mentions... yuck!

Compounded by narrow lanes and one of the worst pieces of road engineering in the country surely....

_________________
If you want to get to heaven - you have to raise a little hell!

Smilies are contagious
They are just like the flu
We use our smilies on YOU today
Now Good Causes are smiling too!

KEEP SMILING
It makes folk wonder just what you REALLY got up to last night!

Smily to penny.. penny to pound
safespeed prospers-smiles all round! !
But the real message? SMILE.. GO ON ! DO IT! and the world will smile with you!
Enjoy life! You only have the one bite at it.

So what do people think of the "Ramp Metering" systems trialled on the M27 (among other places)?

These involve traffic lights on the slip roads forcing you to stop and then pull away into the main trafffic flow at lower than usual speeds . I never did see the results of the trials but the expensively installed system is now not being used.

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Malcolm W.
The views expressed in this post are personal opinions and do not represent the views of Safespeed.

The problem with merging at J34 M6 is made worse if you are following another vehicle onto the M6. You have to watch traffic in your mirrors, AND anticipate what the driver in front will do. If you slow for safety, you lose the momentum to make a clean access.
I usually hang back on the approach bend to allow them to clear, but drivers who dont know the layout will be taken by surprise.

There was a particularly bad accident there a few years ago.

I feel it would be improved by making Lane one LEAVE the M6 into Lancaster, and have 2 lanes pass the junction, allowing drivers to join and filter together AFTER the junction - as is the case with the M55 junction with the M6 at Broughton.

Why have they not considered this?

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From what I saw of those particular ones, not much. I was on the M27 itself so I don't know what they were like from the point of view of people on the slip roads, but they looked too close to the motorway to me. I'm not very surprised to hear they're not in use any more. In effect by stopping people on the slip road they've reduced the ability to get up to a suitable speed at which to merge with existing motorway traffic, and I can't see how that does anybody any favours. I think the number of places where they can be used effectively is probably quite limited. I'm open to the idea in principle, but IMO in practice it needs a longer than average slip road. Too close to the motorway isn't a good idea and too close to the other end will cause problems with queues on the junction itself.

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Make everything as simple as possible, but not simpler - Einstein

They had an experiment at J26 of the M62, limiting the eastbound on ramp to one lane. It actually worked quite well for traffic on the M62 but caused traffic to back up the whole length of the M606.

As Paul frequently says, traffic levels will regulate themselves. If one route becomes over congested then a proportion of the traffic will divert. Tinkering with the flow will not help when the crux of the problem is a severe lack of road space.

Well, when they are used on the M6 in the Walsall area they are right at the top of the sliproad. They are only used when trafic flow is really heavy, under such conditions there's generally no need to accelerate up to 70mph on the sliproad because the rest of the motorway is only doing 30 tops anway.

The junction sliproads I dislike are the ones where the joining road is below the level of the motorway and the sliproad runs uphill. The combination of trying to see whats coming and the use of a less powerful car dragging uphill makes these merges 'concentration focusers'.

You all might like to try joining the M6 to go north at Jn 15 (south end of the A500). A 270 degree turn at 20-25 mph then you have to absolutely 'welly it' to get up to around 55 -60. I have seen several near-misses hear when following a vehicle onto the motorway. The acceleration lane is slightly longer, but nowhere near enough as it was designed in 1963 !!

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Good manners maketh a good motorist

I know this junction well, as my son was in HOPE Hospital Salford for some time, and I negotiated this junction twice a day for two months!
The "locals" seemed to have a unique approach which consisted of driving like the clappers, whichever route they inteded to take, and let the guy behind do all the avoiding. The first three days I was stunned, but after a week, I could cope, and found.... it works!
As you say, it is amazing there are not more accidents, but experience and alertness must win the day on this one - I have no other explanation!
I have never seen an accident along this stretch - only where the traffic was slightly less dense!

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Time to take responsibility for our actions.. and don't be afraid of speaking out!

I will never again stop at Foston services on the A1M northbound. Getting off the A1M is fine. Getting back on after one's Olympic Breakfast in the Little Chef, however, is a different story.

Rejoining it is a case of accelerating to the speed of the running traffic in about 25 metres and hoping that there isn't a wagon coming over the blind summit. Most fearsome.

Rigpig - called traffic lights , installed at the end of the ramp i believe.
Far better way to get round them is if traffic heavy J 9/10 ,SOUTH - detour via A34 to j7

Now i believe the good Commander meant the little tea leaf.
(My suggestion for a new sign is a bloke in a black/white striped shirt, with mask and swag bag over shoulder,possibly carrying jemmy)


Now joining the motorway i try to be doing 70 up the ramp - why - easier to slow down than accelerate.
Simple aint it - at 70 you have manouvering speed over HGV -- if you have to get inbetween two - slowing down to 55 is easier and faster than trying to speed up ( we all aint got sports cars)

How about J15 of thr M6 (Stoke South), in particular the northbound exit slip, which forces most vehicles to slow down to no more than 40mph in order to make the bend, and the northbound entry where you do a tight 270 degree loop at no more than about 30mph, or somewhat slower for trucks.