how do motorway closures work?

Let’s just say that, to pick an entirely random example, National Highways said that they were going to close J18 – J19 of the M4 at 19:00 on Friday, to do some work over the weekend.

How do they actually close it?  Is 7pm when they actually start to cone it off?  So if a driver reached that bit at 6.59pm they might, theoretically be able to pass through?  Or would 7pm be the time when they want all vehicles off the road, and so they’d cone it off earlier to make sure?

I think they just shut the entry to the closed bit and then everyone pops out the other end a bit later. Certainly I have nipped through just before the closure time and all the cones and plant was there ready to go. Suddenly no-one behind me. No one ahead either for a bit so I wondered whether I had ignored the shut signs by accident. Eventually caught some cars so assumed not.

The time is when they start to close it off but they will often start a little bit earlier, not sure they could stop you if you drove through before the official closure time.

Thanks.  Trying to work out how badly my National Express coach might be affected.

It starts 5.5 miles away from the road closure, at 6pm.  So in theory it would be onto that stretch of road by 6.15. If it wasn’t rush hour on a Friday night…

Trying to work out how badly my National Express coach might be affected

It might add a bit of time onto your journey but, given that it feels like every National express bus feels takes about 400 hours to reach its destination, it shouldn’t be too big an impact.

IME, the advertised time is a bit optimistic, they can’t close it early so it can only ever be on time or late.

So if it says closed form 7pm, they’ll start putting cones out at say 6:30, which involves a few miles of pitting them diagonally across lanes 3 and 2 first to filter the traffic into one lane past the junction, then if they’re on schedule they close off lane 1 letting the last car through at 7:00.

IME, the A1 was closed 20mins before the stated time and while the diversion signs were still being put out, leading to a few of us being properly lost somewhere in Northumbria until I fired up Google maps.
This was 4 years ago..YMMV

Varies by motorway. The M1 closures towards the bottom are usually supposed to be from 10pm, but they’re diverting traffic off 30 mins to an hour before this time in my (frustrated!) experience.

usually supposed to be from 10pm, but they’re diverting traffic off 30 mins to an hour before this time in my (frustrated!) experience.

That’s not what I wanted to hear!

But then, that’s later in the evening, so perhaps not quite such an impact.

Surely. Surely they wouldn’t shut the motorway out of a major city in the middle of rush hour on a Friday.  Would they?

7pm isn’t the rush hour, and with people WFH on Friday’s then any rush hour there is s earlier and less busy.

no, but 6pm is!

That stretch of motorway carries over 4,000 vehicles every hour so local roads around me in north Bristol are going to be carnage this weekend.

Work on the basis that it will be closed and you won’t be too far wrong. Contractors would rather max out their working time because they might be on penalties for over-running

Friday afternoon/evening was always prime time for collisions and it doesn’t take much to get to the closure later than scheduled. The diversion route looks horrible https://beta.southglos.gov.uk/a432-badminton-road-m4-overbridge-closure/

That stretch of motorway carries over 4,000 vehicles every hour so local roads around me in north Bristol are going to be carnage this weekend.

Local roads around North Bristol can be carnage any time other than between 01.30 and 04.30…

This Friday? Highways website says closure is …

M4-Both directions

M4 both directions Jct 18 to 19 carriageway closed

18/10/2024  20:45

21/10/2024 06:00

Yeah, that’s near me, they’re moving all the supplies running through the bridge off and burying them under the motorway, then taking the bridge down next year i think, this is the first of 3 closures planned i believe, maybe 4.

As for timings, your bus driver will know, they tend to close it at the time provided, give or take a few minutes, depends on what diversion they’d take, if you’re starting in Bristol, then they might just head down the 420 to Chippenham and join the M4 there, bit higher up and they might use the Westerleigh Road north of the M4, which will be absolute carnage this weekend, i’m avoiding even thinking about that road until next week!

I’ve seen motorway in the process of being closed. They’d started the taper at the central reservation, had closed lane 3 and 2, and I was able to pass in lane 1.  In the mirror I saw HGVs and the odd car continue to nip around the end of the line of cones using the hard shoulder, and then as the guys carried on throwing cones off the back of the lorry the traffic started using the exit slip and then crossing the solid lines and chevrons to get back on to the motorway!  Chaos ?

And spooky’s post is why it’s such a dangerous job.

Generally they work across from one side to the other starting a bit before the closure time.

Slip roads on it’s usually a bit more binary (certainly round me where they are roundabout fed predominantly).  A truck and some cones.

It’s spooky when you’re one of the last ones through.

It’s spooky when you’re one of the last ones through.

And the first one after opening

Try being one of the people making a delivery to the site.  Driving along at 10mph (strictly enforced) in the middle of the night with the orange beacons flashing away and reflecting off the surrounding bushes is very surreal, especially when it’s a long way from the last junction to the site.  I once did J17-16 of the M4 like that, the site was just before the bridge over Brinksworth Road with both directions closed after a fatal accident.  Far, far spookier than during the pandemic, especially as you see the mix of yellow and blue flashing lights appear, drop off the delivery and then go back along the M4 in the wrong direction!

So if it says closed form 7pm, they’ll start putting cones out at say 6:30, which involves a few miles of pitting them diagonally across lanes 3 and 2 first to filter the traffic into one lane past the junction, then if they’re on schedule they close off lane 1 letting the last car through at 7:00.

That pretty much.  They’ll have those trucks with the giant crumple barriers protecting them while they do it, it’s a pretty dangerous operation due to morons not obeying or paying attention.  They can and will report anyone who tries to sneak round at the last second too, don’t even try it!

I’ve been driving around the M4/M5 closures a lot recently on weekday evenings (and others). I’ve never found them to close the road early, but they will have the signs warning of workforce in road (and if a managed motorway, have speed limits), to put the cones down from lanes 3-2-1 on time if they need to get on. However, NEx drivers will know about closures on their route and will know the best way round. A 6:15 pm coach departure time from Bristol or Bath isn’t going to be affected by a 7 pm closure unless it’s running really late anyway.

And as awh says, Highways England says the full closure is at 20:45. So no worries.

Yeah it’s a really horrible job putting the cones out, drivers are so obsessed by getting through they drive like idiots.

We closed a motorway (dual carriageway) as kids. There were some major sewer works taking place so a local road had been closed in preparation. Lots of plywood shuttering had been delivered. Our Goonies style gang of skateboarding warriors pinched a few sheets to build our version of the Powell Peralta* Animal Chin ramp but we needed some structural underpinning wood. We decided to reverse engineer a local farmers fence…….his sheep then escaped onto the A56 southbound and closed it.

Yes we were idiots.

*One of the crew went on to start (and still owns) what would be become a huge worldwide skateboard company, lives in the States and is still a good friend. He’s met Stacy Peralta so the subsequent massive bollocking from parents and school would go on to be worth it. The farmer got his painful revenge some time later…..

Just to clear up any confusion for those who think the M4 closure is just for 3 hours in the middle of the night.

National Highways will be closing the M4 between junctions 18 and 19 in both directions from 7pm on Friday 18 October to 6am on Monday 21 October. The closure is to remove the utilities and services currently in the M4 overbridge and bury them under the M4. To do this safely and to minimise overall disruption, they need to close this section of the M4 for the weekend.

Irrespective of the roadworks when you get on the bus just hum the ‘official’ National Express theme tune and ‘it will make you smile ‘…

National Highways will be closing the M4 between junctions 18 and 19 in both directions from 7pm on Friday 18 October to 6am on Monday 21 October.

So, safe to say a weekend of riding over the bridge is a no-no this weekend then as an East Bristol resident?

It’s based on a traffic count. Too busy and it gets delayed, no traffic and it may go out a little earlier

Well Reading has had the joy of M4 traffic being diverted through and around it recently. The whole thing went extremely smoothly no issues*

(*It did not).