Another bridge strike

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RichardA35
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Re: Another bridge strike

Post by RichardA35 »

rhyds wrote: Tue May 03, 2022 10:05At Pen-y-Ffordd railway station there's a bridge. Its a pretty low bridge, according to the massive signs on it its got a passable height of 12 feet, 9 inches, or 3.8m in metric
Unless I'm reading TSRGD incorrectly, that large circular sign indicates the height of vehicle that is prohibited not the bridge headroom.
Once that is understood all the other signs make sense apart from the A5104 sign wich is wrong and should replicate the other circular signs with 12'9" 3.8m.

Or have I got it wrong as a mere builder that there is no need for the heights on the circular and triangular signs to be the same as long as they are consistent (they are not in this case as noted for the A5104 above).
Tell me if I'm wrong but given the triangular signs 530 warn of "Maximum headroom available at hazard" and the circular signs 629.2 prohibit "Vehicles exceeding height indicated", they can show different heights as they are referring to the height of different objects (the hazard and the vehicle).
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rhyds
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Re: Another bridge strike

Post by rhyds »

RichardA35 wrote: Tue May 03, 2022 11:29
rhyds wrote: Tue May 03, 2022 10:05At Pen-y-Ffordd railway station there's a bridge. Its a pretty low bridge, according to the massive signs on it its got a passable height of 12 feet, 9 inches, or 3.8m in metric
Unless I'm reading TSRGD incorrectly, that large circular sign indicates the height of vehicle that is prohibited not the bridge headroom.
Once that is understood all the other signs make sense apart from the A5104 sign wich is wrong and should replicate the other circular signs with 12'9" 3.8m.

Or have I got it wrong as a mere builder that there is no need for the heights on the circular and triangular signs to be the same as long as they are consistent (they are not in this case as noted for the A5104 above).
Tell me if I'm wrong but given the triangular signs 530 warn of "Maximum headroom available at hazard" and the circular signs 629.2 prohibit "Vehicles exceeding height indicated", they can show different heights as they are referring to the height of different objects (the hazard and the vehicle).
Except the figures aren't consistent over the circular signs either!

On the A550, heading towards the roundabout the ADS shows 13', while a secondary warning sign not 25yds later shows 12' 9"

https://www.google.com/maps/@53.1447417 ... 384!8i8192

And the roudabout itself, which is the last convenient and safe point to turn around, shows 13' again!

Its not that difficult to get signage like this correct and consistent especially as a lot of it seems new/very recent. Even if the warning signs can legally be 3" higher than the actual bridge what logical reason would anyone have to sign a low bridge as higher than it actually is? All an HGV driver or insurance company needs to do is quickly check streetview and the £10k+ repair bills fall on Network Rail and Flintshire CC, not the trucker or their insurer.
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Bryn666
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Re: Another bridge strike

Post by Bryn666 »

RichardA35 wrote: Tue May 03, 2022 11:29
rhyds wrote: Tue May 03, 2022 10:05At Pen-y-Ffordd railway station there's a bridge. Its a pretty low bridge, according to the massive signs on it its got a passable height of 12 feet, 9 inches, or 3.8m in metric
Unless I'm reading TSRGD incorrectly, that large circular sign indicates the height of vehicle that is prohibited not the bridge headroom.
Once that is understood all the other signs make sense apart from the A5104 sign wich is wrong and should replicate the other circular signs with 12'9" 3.8m.

Or have I got it wrong as a mere builder that there is no need for the heights on the circular and triangular signs to be the same as long as they are consistent (they are not in this case as noted for the A5104 above).
Tell me if I'm wrong but given the triangular signs 530 warn of "Maximum headroom available at hazard" and the circular signs 629.2 prohibit "Vehicles exceeding height indicated", they can show different heights as they are referring to the height of different objects (the hazard and the vehicle).
They can but why would you introduce this ambiguity into signs? The whole point of traffic signs is to be clear and concise and engaging in pedantry over "is it the height of the bridge or the height of the vehicle" doesn't help road users.

If the measured height is 13' then the signs should say 12'9" and converted to metric accordingly, which would be 3.8m using the rounding down rules in TSM 4. You don't have roundels saying 12'9" and triangles saying 13'.

People trying to be clever when designing road signs is why we have so much garbage on the network to begin with.
Last edited by Bryn666 on Tue May 03, 2022 13:14, edited 1 time in total.
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Re: Another bridge strike

Post by rhyds »

Bryn666 wrote: Tue May 03, 2022 12:22
RichardA35 wrote: Tue May 03, 2022 11:29
rhyds wrote: Tue May 03, 2022 10:05At Pen-y-Ffordd railway station there's a bridge. Its a pretty low bridge, according to the massive signs on it its got a passable height of 12 feet, 9 inches, or 3.8m in metric
Unless I'm reading TSRGD incorrectly, that large circular sign indicates the height of vehicle that is prohibited not the bridge headroom.
Once that is understood all the other signs make sense apart from the A5104 sign wich is wrong and should replicate the other circular signs with 12'9" 3.8m.

Or have I got it wrong as a mere builder that there is no need for the heights on the circular and triangular signs to be the same as long as they are consistent (they are not in this case as noted for the A5104 above).
Tell me if I'm wrong but given the triangular signs 530 warn of "Maximum headroom available at hazard" and the circular signs 629.2 prohibit "Vehicles exceeding height indicated", they can show different heights as they are referring to the height of different objects (the hazard and the vehicle).
They can but why would you introduce this ambiguity into signs? The whole point of traffic signs is to be clear and concise and engaging in pedantry over "is it the height of the bridge or the height of the vehicle" doesn't help road users.

If the measured height is 13" then the signs should say 12'9" and converted to metric accordingly, which would be 3.8m using the rounding down rules in TSM 4. You don't have roundels saying 12'9" and triangles saying 13".

People trying to be clever when designing road signs is why we have so much garbage on the network to begin with.
A 13" road bridge would be a struggle for anything other than a cat!
Built for comfort, not speed.
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Bryn666
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Re: Another bridge strike

Post by Bryn666 »

rhyds wrote: Tue May 03, 2022 12:43
Bryn666 wrote: Tue May 03, 2022 12:22
RichardA35 wrote: Tue May 03, 2022 11:29 Unless I'm reading TSRGD incorrectly, that large circular sign indicates the height of vehicle that is prohibited not the bridge headroom.
Once that is understood all the other signs make sense apart from the A5104 sign wich is wrong and should replicate the other circular signs with 12'9" 3.8m.

Or have I got it wrong as a mere builder that there is no need for the heights on the circular and triangular signs to be the same as long as they are consistent (they are not in this case as noted for the A5104 above).
Tell me if I'm wrong but given the triangular signs 530 warn of "Maximum headroom available at hazard" and the circular signs 629.2 prohibit "Vehicles exceeding height indicated", they can show different heights as they are referring to the height of different objects (the hazard and the vehicle).
They can but why would you introduce this ambiguity into signs? The whole point of traffic signs is to be clear and concise and engaging in pedantry over "is it the height of the bridge or the height of the vehicle" doesn't help road users.

If the measured height is 13" then the signs should say 12'9" and converted to metric accordingly, which would be 3.8m using the rounding down rules in TSM 4. You don't have roundels saying 12'9" and triangles saying 13".

People trying to be clever when designing road signs is why we have so much garbage on the network to begin with.
A 13" road bridge would be a struggle for anything other than a cat!
It's the new modal filtering system. Everyone loves cats, right? Fixed...
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rhyds
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Re: Another bridge strike

Post by rhyds »

Bryn666 wrote: Tue May 03, 2022 13:13 It's the new modal filtering system. Everyone loves cats, right? Fixed...
Nah, first Hilux or D-max truck that comes up to it is going straight over it, Dukes of Hazzard style
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Re: Another bridge strike

Post by Alderpoint »

Bryn666 wrote: Tue May 03, 2022 12:22 If the measured height is 13" then the signs should say 12'9" and converted to metric accordingly, which would be 3.8m using the rounding down rules in TSM 4. You don't have roundels saying 12'9" and triangles saying 13".
I queried this when the local railway bridge was replaced recently and the height warning signs replaced with a new height restriction signs with a lower height.

The Network Rail PM told me that the old height warning sign was based on the actual clearance height between the road surface and the underside of the bridge, whereas the new height restriction sign is based on the maximum height of a maximum-length vehicle that can fit underneath so due to the dip in the road this is less than the vertical distance immediately under the bridge.
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Re: Another bridge strike

Post by Bryn666 »

Alderpoint wrote: Tue May 03, 2022 13:21
Bryn666 wrote: Tue May 03, 2022 12:22 If the measured height is 13" then the signs should say 12'9" and converted to metric accordingly, which would be 3.8m using the rounding down rules in TSM 4. You don't have roundels saying 12'9" and triangles saying 13".
I queried this when the local railway bridge was replaced recently and the height warning signs replaced with a new height restriction signs with a lower height.

The Network Rail PM told me that the old height warning sign was based on the actual clearance height between the road surface and the underside of the bridge, whereas the new height restriction sign is based on the maximum height of a maximum-length vehicle that can fit underneath so due to the dip in the road this is less than the vertical distance immediately under the bridge.
Yes, this is correct - if the carriageway creates a vertical levels shift then the headroom will be adjusted accordingly. Long load vehicles will still get stuck if the road crests or dips and causes trailers to rise/fall underneath the fixed structure.
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Re: Another bridge strike

Post by MotorwayGuy »

This bridge on the South Circular was struck again the other day.

The signed height keeps getting changed and isn't consistent which doesn't help:
2009 - 14' 9"
2017 - 14' 3" triangle
2021 - 14' 6"

(14' 6" on this botch)
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Re: Another bridge strike

Post by WHBM »

rhyds wrote: Tue May 03, 2022 12:04 Its not that difficult to get signage like this correct and consistent especially as a lot of it seems new/very recent. Even if the warning signs can legally be 3" higher than the actual bridge what logical reason would anyone have to sign a low bridge as higher than it actually is? All an HGV driver or insurance company needs to do is quickly check streetview and the £10k+ repair bills fall on Network Rail and Flintshire CC, not the trucker or their insurer.
That's just not so. The highways budget is not some bottomless cash pot for anything that you screw up. The basic legal premise of highways is "the roads are as you find them". It is up to the driver to handle things appropriately within that. There are plenty of restricted layouts of all sorts not signed.
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Re: Another bridge strike

Post by Bryn666 »

WHBM wrote: Tue May 03, 2022 16:49
rhyds wrote: Tue May 03, 2022 12:04 Its not that difficult to get signage like this correct and consistent especially as a lot of it seems new/very recent. Even if the warning signs can legally be 3" higher than the actual bridge what logical reason would anyone have to sign a low bridge as higher than it actually is? All an HGV driver or insurance company needs to do is quickly check streetview and the £10k+ repair bills fall on Network Rail and Flintshire CC, not the trucker or their insurer.
That's just not so. The highways budget is not some bottomless cash pot for anything that you screw up. The basic legal premise of highways is "the roads are as you find them". It is up to the driver to handle things appropriately within that. There are plenty of restricted layouts of all sorts not signed.
A highway authority with an improperly signed bridge isn't going to win a court case, in fact it would probably find itself going up and through to the Lords. The general finding from Gorringe would NOT apply in this situation, as there is a statutory duty on the highway authority's part to ensure the bridge is correctly signed, as per Section 122 of the RTRA 1984 as there is with any other mandatory restriction or compulsion. There is not a statutory duty to signpost a bend, or something else which falls under "the roads are as you find them".
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Re: Another bridge strike

Post by rhyds »

WHBM wrote: Tue May 03, 2022 16:49
rhyds wrote: Tue May 03, 2022 12:04 Its not that difficult to get signage like this correct and consistent especially as a lot of it seems new/very recent. Even if the warning signs can legally be 3" higher than the actual bridge what logical reason would anyone have to sign a low bridge as higher than it actually is? All an HGV driver or insurance company needs to do is quickly check streetview and the £10k+ repair bills fall on Network Rail and Flintshire CC, not the trucker or their insurer.
That's just not so. The highways budget is not some bottomless cash pot for anything that you screw up. The basic legal premise of highways is "the roads are as you find them". It is up to the driver to handle things appropriately within that. There are plenty of restricted layouts of all sorts not signed.
Indeed so, and if a truck hits a bridge then its the truck's driver that should be liable. However, if the signage is ambiguous as to how much clearance there actually is then there should be a valid defence for that.
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Re: Another bridge strike

Post by Bryn666 »

rhyds wrote: Tue May 03, 2022 17:02
WHBM wrote: Tue May 03, 2022 16:49
rhyds wrote: Tue May 03, 2022 12:04 Its not that difficult to get signage like this correct and consistent especially as a lot of it seems new/very recent. Even if the warning signs can legally be 3" higher than the actual bridge what logical reason would anyone have to sign a low bridge as higher than it actually is? All an HGV driver or insurance company needs to do is quickly check streetview and the £10k+ repair bills fall on Network Rail and Flintshire CC, not the trucker or their insurer.
That's just not so. The highways budget is not some bottomless cash pot for anything that you screw up. The basic legal premise of highways is "the roads are as you find them". It is up to the driver to handle things appropriately within that. There are plenty of restricted layouts of all sorts not signed.
Indeed so, and if a truck hits a bridge then its the truck's driver that should be liable. However, if the signage is ambiguous as to how much clearance there actually is then there should be a valid defence for that.
https://assets.publishing.service.gov.u ... otocol.pdf may be worth a read - it states who is responsible for what.
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Re: Another bridge strike

Post by Chris Bertram »

rhyds wrote: Tue May 03, 2022 12:43
Bryn666 wrote: Tue May 03, 2022 12:22
RichardA35 wrote: Tue May 03, 2022 11:29 Unless I'm reading TSRGD incorrectly, that large circular sign indicates the height of vehicle that is prohibited not the bridge headroom.
Once that is understood all the other signs make sense apart from the A5104 sign wich is wrong and should replicate the other circular signs with 12'9" 3.8m.

Or have I got it wrong as a mere builder that there is no need for the heights on the circular and triangular signs to be the same as long as they are consistent (they are not in this case as noted for the A5104 above).
Tell me if I'm wrong but given the triangular signs 530 warn of "Maximum headroom available at hazard" and the circular signs 629.2 prohibit "Vehicles exceeding height indicated", they can show different heights as they are referring to the height of different objects (the hazard and the vehicle).
They can but why would you introduce this ambiguity into signs? The whole point of traffic signs is to be clear and concise and engaging in pedantry over "is it the height of the bridge or the height of the vehicle" doesn't help road users.

If the measured height is 13" then the signs should say 12'9" and converted to metric accordingly, which would be 3.8m using the rounding down rules in TSM 4. You don't have roundels saying 12'9" and triangles saying 13".

People trying to be clever when designing road signs is why we have so much garbage on the network to begin with.
A 13" road bridge would be a struggle for anything other than a cat!
This sounds like a Spinal Tap "Stonehenge" situation.
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Re: Another bridge strike

Post by WHBM »

Bryn666 wrote: Tue May 03, 2022 17:05 https://assets.publishing.service.gov.u ... otocol.pdf may be worth a read - it states who is responsible for what.
That does indeed define responsibility for placing signage - it does not define legal liability, especially where, as in the discussion above, it's just a matter of a few inches difference between signs. If my vehicle was plated at 14'3" high I wouldn't barrel through a 14'6" signed restriction.
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Re: Another bridge strike

Post by Bryn666 »

WHBM wrote: Tue May 03, 2022 18:53
Bryn666 wrote: Tue May 03, 2022 17:05 https://assets.publishing.service.gov.u ... otocol.pdf may be worth a read - it states who is responsible for what.
That does indeed define responsibility for placing signage - it does not define legal liability, especially where, as in the discussion above, it's just a matter of a few inches difference between signs. If my vehicle was plated at 14'3" high I wouldn't barrel through a 14'6" signed restriction.
It does refer you back to the RTRA and legal duties to place signs though, which would mean defective signs would be seen as a contributory factor in a court case.
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Re: Another bridge strike

Post by RichardA35 »

Bryn666 wrote: Tue May 03, 2022 18:58
WHBM wrote: Tue May 03, 2022 18:53
Bryn666 wrote: Tue May 03, 2022 17:05 https://assets.publishing.service.gov.u ... otocol.pdf may be worth a read - it states who is responsible for what.
That does indeed define responsibility for placing signage - it does not define legal liability, especially where, as in the discussion above, it's just a matter of a few inches difference between signs. If my vehicle was plated at 14'3" high I wouldn't barrel through a 14'6" signed restriction.
It does refer you back to the RTRA and legal duties to place signs though, which would mean defective signs would be seen as a contributory factor in a court case.
There's a statutory defence for S41 of the Highways Act (duty to maintain) under S58. However only if there is a competent scheme of inspection (which would appear to be lacking in the case highlighted as a competent inspector would pick up such anomalies) and IMV it would probably fall outside the reasonableness test of "not dangerous for traffic" especially if they had been made aware.
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Re: Another bridge strike

Post by WHBM »

There's a legal procedure (I'm only peripherally involved in legalities [our lawyer works in the office opposite], not qualified, so bear with me) which is a distinction between positive and negative "entreat", as I think the lawyers say.

If I put up a sign by an electric railway, for example, and say "Come on this way, it's safe" then that is positive, and if it turns out not to be and there is an accident, there is a liability. But a sign that just says "danger, electric railway" is negative, it is seen as a warning, not an instruction. And the same accident would be regarded differently. Which is why the signs always say it this way round.

So highway authorities, as they used to, might sign "danger, low bridge", and it's up to you to negotaite it appropriately. If you say "Low bridge, 14' ", then it's seen as a guideline that you need to look more carefully, consider your vehicle, etc. But it's a warning, not saying the sign placer has a legal liability.
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Re: Another bridge strike

Post by SteelCamel »

Bryn666 wrote: Tue May 03, 2022 10:46 There is also the weird rule that you have to round down no matter what so signs could potentially be 6 inches lower than reality. Once HGVs suss this out... that's when trouble starts.
I know of one location where buses signed as 14ft 6in used to regularly pass under a bridge signed as 14ft 3in. There was a lot of clearance - looked like about a foot!
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Re: Another bridge strike

Post by aj444 »

There is a regular double decker bus service under this bridge;
https://www.google.com/maps/@52.5989989 ... 384!8i8192
...but the sign is a triangle not a circle....
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