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Road closed to high sided vehicles- that means YOU - Mapmaker
Crossing the A66 yesterday, the illuminated signs said "road closed to high sided vehicles" - and with good reason; I crossed it at 50mph. Along the way I overtook an HGV.

I dare say that a couple of miles later he might have been having second thoughts about his decision to ignore the signs, as we passed an HGV lying on its side... scary.
Road closed to high sided vehicles- that means YOU - Andrew-T
Perhaps an EU driver who doesn't read English signs? (they're on the wrong side if the road)

I drove up the A1 near Durham a couple of years ago - trucks were scattered along the roadside. As the wind was from the west, overtaking a wagon felt a bit dodgy. At about the same time there were signs along the A49 in Cheshire in English with corresponding ones in Polish.
Road closed to high sided vehicles- that means YOU - FotheringtonThomas
Perhaps an EU driver who doesn't read English signs? (they're on the wrong side if
the road)


If they can't understand the system, they shouldn't be on the road.
Road closed to high sided vehicles- that means YOU - L'escargot
What's the maximum height a vehicle can be before it's classed as high-sided?
Road closed to high sided vehicles- that means YOU - oldnotbold
One that you can not see over when on your high horse.
Road closed to high sided vehicles- that means YOU - Cliff Pope
I have to say that overtaking a high-sided vehicle that is about to be blown over is probably just as dangerous.
Road closed to high sided vehicles- that means YOU - Mapmaker
>>I have to say that overtaking a high-sided vehicle that is about to be blown over is probably just as dangerous.

Indeed - but fortunately we passed it just as we were climbing out of Bowes - and wondering what the weather was going to be like on the top.
Road closed to high sided vehicles- that means YOU - Muggy
Ordinary lightweight cars are at risk in high winds as well; mine has a tare weight of about 700Kg and is a nightmare to handle in a strong crosswind.

I wonder whether the signs should say "lightweight and high sided vehicles" instead?
Road closed to high sided vehicles- that means YOU - Dave_TD
What's the maximum height a vehicle can be before it's classed as high-sided?


It depends on the severity of the wind, I guess. I have suffered from quite alarming buffetting whilst driving a Sprinter van before now.

Most competent HGV drivers would (should?) know when the conditions are too hazardous for them to carry on.
Road closed to high sided vehicles- that means YOU - TonyJ
For high winds eg last weekend the Forth Road Bridge extends the ban to cars with roof boxes.
Road closed to high sided vehicles- that means YOU - Cliff Pope
Vehicle speed must be a factor too. Unless the wind is so strong that even a stationary lorry is blown over, then there must be a speed at which it is safe to proceed.
Road closed to high sided vehicles- that means YOU - BobbyG
My memory may be failing on me, but I seem to recall that in years gone by, with the Forth Road Bridge, in cases of high winds rather than banning high sided vehicles, they used to insist they "doubled up" and crossed together? I assume the theory being you would only get blown slightly onto the adjacent lorry and then back onto your wheels again? BUt surely that alone could result in damage? Am I right and if so why is that stopped now?

Probably H&S
Blame culture
When they blow over then it will be two lanes closed rather than one!!
Road closed to high sided vehicles- that means YOU - Andrew-T
>Unless the wind is so strong that even a stationary lorry is blown over ..

And that does happen. Often to those spare wagons parked by the motorway with slogans on.
Road closed to high sided vehicles- that means YOU - maz64
Vehicle speed must be a factor too.


That sounds right, but why?
Road closed to high sided vehicles- that means YOU - Fullchat
Difference between an empty lorry and one weighing in at 42 tonnes as regards being blown over particularly if it is loaded low down.
Curtain siders open their curtains to reduce the sail effect.
Road closed to high sided vehicles- that means YOU - Number_Cruncher
>>That sounds right, but why?

Because what's important is the wind speed and direction relative to the vehicle.

In this regard, the wind speed relative to the ground and the vehicle speed must be combined in a vectorial sense to obtain the resultant wind.

In other words, as the vehicle speeds up, the wind speed relative to the vehicle *may also increase, and thus a larger aerodynamic force may be exerted.

* in the case of a pure tail wind, of course, it may be possible to produce the effect of no wind relative to the vehicle!



Road closed to high sided vehicles- that means YOU - Cliff Pope
Also I think there is the increasing risk of wind-induced yawing followed by over-correction and swerving.
Road closed to high sided vehicles- that means YOU - Mapmaker
And I imagine also road surface - camber, potholes etc - can introduce torsional forces on the trailer, which can reduce the activation energy required to topple the beast when combined with the wind.
Road closed to high sided vehicles- that means YOU - pda
Or of course there's the professional lorry drivers theory.

When your bum cheeks start to clench it's time to stop :)

Pat
Road closed to high sided vehicles- that means YOU - ninetynine

Hi Mapmaker

I am investigating an accident on the A66 on 11 January 2009, where a high-sided vehicle was blown over

In view of your message, I think that you may be able to help me

It would be much appreciated if you could 'phone me on 0161 235 7512, during "office" hours

If you are able to ring me, I'll 'phone you back straight away

Thanks in anticipation

Road closed to high sided vehicles- that means YOU - Sofa Spud

I was encountered a very stormy, squally shower on the way home from work.

There must have been gusts up to storm force or more. In one exposed place the driver of a 7.5 tonne box van had stopped on the carriageway. Gusts of wind were lifting the wheels on the windward side off the ground, threatening to blow the van onto its side.

Presumably it was either empty or had a very light load.