The M5 in summer

[Bryn666]

At ~60k AADT that makes the M5 quieter than the M65 around the south of Blackburn (J4-6) (~72k AADT).

The M65 is D2M as well.

[nowster]

The M65 is D2M as well.

With room for a pony... online widening.

[RichardA35]

At ~60k AADT that makes the M5 quieter than the M65 around the south of Blackburn (J4-6) (~72k AADT).

The M65 is D2M as well.

I get a nosebleed that far north these days...

[DavidBrown]

With only ~60k AADT, in the autumn and spring, you'll often find daytime offpeak lane 1 closures (with the taper formed in lane 1 not lane 3 and the traffic switched) implemented on the M5 south of J21 which is pretty unthinkable on most of the other major English motorways.

And that's exactly the problem with the M5 - at most times, like you say, you can get away with minor roadworks with no issues. But, as some stories of gridlock earlier in the thread have hinted at, if you tried that on the last Saturday of July you'd end up with a 30-mile queue quite easily. In that respect, the M5 is like no other motorway in Britain, and as I said again earlier in this thread, there is actually very little that can be done to improve the M5. You could prehaps improve a couple of junctions (e.g. extend the sliproads at J25 and J27 where traffic tends to queue back onto the mainline), and possibly replace the MS1s with MS3s so that information about incidents are communicated effectively (as opposed to the generic 50 sign that is seemingly a permament fixture on the M5) and that's about all that you can do, really.

[Thryduulf]

Other than around Bristol, there isn't much that needs to be done to the M5. What needs to be done is to provide alternatives to the M5 so that when there are problems the traffic has somewhere to go other than join the back of the queue.

As for the Bristol area, well the very first thing to do would be to extend the climbing lane to become a lane drop at J17 - as I think was the original plan. I used to commute that way and at peak shopping times, particularly around Christmas it was much quicker to come of at J18 and go up through west Bristol.

The next thing that needs sorting is J16, which would be massively overloaded even if it wasn't tangled up with the M4 interchange.

[gepree68]

As for the Bristol area, well the very first thing to do would be to extend the climbing lane to become a lane drop at J17 - as I think was the original plan.

Is that original plan related to the following map:

in a report a few years ago? The idea seems to be to have an extra northbound exit slip at J17 tote you straight to the roundabout next to Asda. Also there would be a new northbound entry slip taking you onto the M5 from the roundabout that connects Lysander Road to the A4018 (next to where Harry Ramsden used to be).

[Thryduulf]

No, that's the first time I've seen that proposal.
What I remember is the initial proposals on the HA site for the three climbing lanes project, where the northbound climbing lane would start where it does currently just after the slightly-too-narrow railway bridge but carry on for the short distance after the summit to become a lane drop at J17 (I think the wording was something like "due to the proximity of the junction"). Indeed until it became clear that the works on the ground weren't extending that far I thought that was still the plan. It seems incredibly pointless penny pinching given that would have been the easiest stretch to construct!

Without that one railway bridge (which would be incredibly simple to replace as it's a lightly-trafficed freight only line with a parallel bridge that is wide enough for D4M, from memory it wouldn't even need significant realignment of abutments) there could be a continuous crawler/junction hopping/Shopping centre lane between J18 and J17.

As for the proposal you link to, it seems rather ambitious in some respects for what it does but it would work well I think if anybody was prepared to pay for it. The omission of a second southbound on slip from the labelled "Harry Ramsden roundabout" (the ADS simply call it "Cribbs Causeway" or "Cribbs Causeway Roundbaout" iirc) is a little surprising as it would reduce potentially conflicting flows at the roundabout.

[SteveA30]

Wasn't sure which thread to put this in but, this is as good as any. Found in the Bristol Archive. No date but, probably 1970/71, as there is no decking on the bridge yet, which caused all the delays. The trail of oil off the M5 from Clevedon illustrates that they had their own private motorway into Bristol for a few years. The new link to the unbuilt docks is under way. As with most old road photos, the lack of trees is startling, so open it all is. Gordano is laid out but, unbuilt.

[BOH]

Wasn't sure which thread to put this in but, this is as good as any. Found in the Bristol Archive. No date but, probably 1970/71, as there is no decking on the bridge yet, which caused all the delays. The trail of oil off the M5 from Clevedon illustrates that they had their own private motorway into Bristol for a few years. The new link to the unbuilt docks is under way. As with most old road photos, the lack of trees is startling, so open it all is. Gordano is laid out but, unbuilt.

Wasn't the M5 Avonmouth Bridge one of the bridges in the UK where completion was delayed by the infamous box girder problems?

[SteveA30]

Yes, opened in May 74 instead of I think, 72.

[booshank]

Might be slightly to the north of the scope of this but I think the M5 carriageways narrowing from three to two lanes through the Almondsbury interchange is a big problem here. I often seem to see big tailbacks, sometimes stationary, southbound approaching this. I cant say about northbound on the other side, as I don't really use it as it's not on the way to anywhere for me.

[DavidBrown]

I did find this video the other day of the opening of the Avonmouth Bridge. Interesting to see roadworks and delays on the bridge from day 1 - nothing changes!

[wrinkly]

Even more interesting, the film it showed me next about the Tamar bridge.

[SteveA30]

Well, September is late summer to me, if not the Met. Office.
The M5 weekend crash caused 2 days of problems north of Bristol, J16-14. Only M4 traffic could get to J15.
By mid afternoon, traffic levels closed the gaps between lights and created a queue from A38 Falfield to Almondsbury and beyond on M5 to Avonmouth, plus M4 and A38 from Bristol.

[Sou'wester]

I was thinking about this yesterday. Should HE consider liaising with local authorities about official diversion routes.

For example if the M5 between J16 and 14 is shut as per the weekend. The traffic lights on the A38 should be mandatory switched off and the road comes under temporary jurisdiction of HE.

Yes, it will annoy the locals (I am a local to this particular stretch), but it should help maintain the flow of traffic and minimise delays.

[SteveA30]

I'd already written to S.G.C.C. about this re the summer overspill on to the A38, earlier this year. They said it is run by the MOVA system, which can't be altered. I did a MOVA thread in Street Furniture, which only has 9 posts so, a look at that may answer your point.

Eventually, the traffic queue was continuous from J14 back to J16 and beyond so, the A38 was overwhelmed, lights or no lights.

[Isleworth1961]

I was thinking about this yesterday. Should HE consider liaising with local authorities about official diversion routes.

For example if the M5 between J16 and 14 is shut as per the weekend. The traffic lights on the A38 should be mandatory switched off and the road comes under temporary jurisdiction of HE.

Yes, it will annoy the locals (I am a local to this particular stretch), but it should help maintain the flow of traffic and minimise delays.

Too right it will annoy the locals! Turning off the lights would virtually block or even trap those who have to cross from one side of the A38 to the other. I'm local too (can see the A38 from my house) and I have seen the chaos an M5 closure causes. All it will then need is for someone to chance pulling out into a tiny break in the almost continuous traffic for there to be a collision and then it's a complete halt to any traffic whatsoever.

[Sou'wester]

People seems to manage fine pulling out of Fernhill from Tockington and many other unsignallised junctions when the A38 is rammed. You’re assuming nobody will let anyone out.

Yes, access will take longer for locals - but this is more than NIMBYism. There is a massive cost to the economy when a motorway is shut for such an extensive period of time.

[SteveA30]

I see plenty of examples of locals being let out of side turns or, flashed to turn right through the queues. The M fivers know they are getting in the way. I was thinking more of adjusting MOVA to allow longer greens for A38, until the congestion has gone, rather than switching them off altogether. The Thornbury double lights really could just be double mini rbts for the local traffic, which would hold up the diversions far less. The bottom photo shows how little local traffic is approaching from the other side.

The locals in the 60's and early 70's had to deal with this, as there were no lights and heavy traffic all year round, especially on summer weekends.

New in Roadhog.....guess.

[Isleworth1961]

I see plenty of examples of locals being let out of side turns or, flashed to turn right through the queues. The M fivers know they are getting in the way. I was thinking more of adjusting MOVA to allow longer greens for A38, until the congestion has gone, rather than switching them off altogether. The Thornbury double lights really could just be double mini rbts for the local traffic, which would hold up the diversions far less. The bottom photo shows how little local traffic is approaching from the other side.
The locals in the 60's and early 70's had to deal with this, as there were no lights and heavy traffic all year round, especially on summer weekends.

Adjusting the lights timing is about the only sensible thing that can be done when the A38 is used during an M5 closure. If the lights were switched off completely, and the traffic was flowing well in both directions and in the case of the weekend M5 closure which was in both directions getting out of Thornbury would be near impossible. Before the lights were installed these were simple junctions, and with the traffic at that time very long queues built up to get onto the A38, mostly in the mornings, but also in the evenings, even after the NSL was reduced to 40mph at Alveston and Grovesend. Most working people in Thornbury use the A38 to get to work, and many people use the A38 to get to work in Thornbury. There's also a fair sized trading estate which generates a lot of traffic, including many HGVs. Thornbury has grown considerably and is not the sleepy little sidelined town it was in the 1960s, and at much of the day A38 traffic between Almondsbury and Alveston/Grovesend can be almost as heavy as it was most of the year pre-M5...
Apart from the tailbacks waiting to get onto the A38, there had been countless collisions at both junctions (and at Rudgeway, turning for a busy HGV route to Yate), several fatal, so something had to be done about it. Mini roundabouts were apparently considered at these junctions, but I gather they were felt to be too dangerous despite the now lower speed limit, especially at Grovesend as it is in a dip with long-ish descents to the bottom. The A38 is fairly straight through all these junctions, and as we all know, many drivers just don't slow down at mini roundabouts when going 'straight on' (and we have issues with this in Thornbury itself...), hence the installation of the lights, although they weren't all installed at the same time. The lights work fine for normal local traffic levels, it's just when something like an M5 closure happens they don't help it.