Driving from Cardiff to avonmouth earlier signs flashing m48 closed to highsided veichles use m4.
How high is high though ? 12ft 13ft 14ft
If its due to wind then i suspect anything bigger than a van, but would be helpful if they specified. Does beg the question as to whether they can technicality prosecute since they didnt say.
Pretty sure if you go over in a 16’ double decker they might have something to say. 
According to an old transport manager of ours high sided only applied to our double deck trailers. She didn’t last long funnily enough.
sent using smoke signals
Be good if anyone knew the rules.
Now winter and bad weather approaching.
Say Dartford crossing is shut to highsiders. 1st how high would that be. And 2nd how do you get round then.
edd1974:
Be good if anyone knew the rules.
Now winter and bad weather approaching.
Say Dartford crossing is shut to highsiders. 1st how high would that be. And 2nd how do you get round then.
When it’s been closed in the past you use one side of the tunnel
I was always told that to qualify for high vehicle status the vehicle had to be higher than it was wide. Not sure what to make of that tbh as it would make anything on two wheels or four hooves a high vehicle! 
edd1974:
Be good if anyone knew the rules.
Now winter and bad weather approaching.
Say Dartford crossing is shut to highsiders. 1st how high would that be. And 2nd how do you get round then.
The long way round… via Heathrow
the maoster:
I was always told that to qualify for high vehicle status the vehicle had to be higher than it was wide. Not sure what to make of that tbh as it would make anything on two wheels or four hooves a high vehicle!
Nooooo…That makes my 3.2m High Motorhome high sided!!, but it is like a sodding kite in a good blow.
Severn bridge wind protocols
40 knots: Advance warning signs will be displayed. Bridge/s will remain open to all vehicles under 6’9″ (2.1m). The use of the M48 Severn Bridge by restricted vehicles (those over 2.1m in height and motorcycles) will not be permitted and an alternative route must be found. Filtering operates between 06:00 and 22:00. If conditions persist, the bridge will be closed to all traffic between 22:00 and 06:00.
Highways England Traffic Officers will initially provide a visible presence to help reinforce the changes. Avon & Somerset and/or Gwent Police Forces will also support the operation.
60 knots: Bridge/s closed to all traffic.
9ft, but I can’t find the article/document it was mentioned in any longer…grrr
While back I got a bollickin for going over the Humber bridge in a 3.5ton Iveco Daily box van when closed to high sided vehicles, wouldn’t have blown over as I had 2 x 1 ton pallets of cashew nuts in the back. Glad the wet and windy weather kept the mobile weighbridge away though …
mardybum:
9ft, but I can’t find the article/document it was mentioned in any longer…grrr
Or how about 6’9 as I posted directly above you…
info taken from the Severn Bridge website.
Traffic Scotland state…
Humberside Police state…
Hard and fast rules don’t exist in the U.K. apparently. Those you mention above of 6’9” vary from bridge board to bridge board. Personally, I’d go with what Plod say
In regards to the m48 Severn bridge, which this thread started about, I’ll go with thier official policy, which is 6’9.
There are height detection cameras on the entrance to the bridge, go through those when the high wind protocol is in force and you’ll be getting a nice letter through the door.
Another snippet from thier website regarding the protocol.
Drivers ignoring advice and attempting to use the bridge will be committing an offence and may face prosecution
Is a loaded tipper going to get blown over? No. It it higher than a van? Yes.
Is a car transporter at 16 foot going to get blown over? I wouldn’t have thought so with all the gaps the wind has to go through. Is it higher than a van? Yes.
Is a tanker going to get blown over? No. Is it higher than a van? Yes.
Is an empty Luton van going to get blown over? Quite possible. Is it higher than a van? Oh wait it is a van.
Just say high sided vehicles is a bit vague and needs clarifying.