Same bridge struck three times in under a week

[Dr Hoo]

Text of article linked to earlier.

Thanks for that. I used the line twice yesterday but evidently ‘missed’ the incident.

 

[AndrewE]

Does that technology exist yet? If not, it's no good waiting until it does. A system that detected when a trailer has been changed could work, but would need every tractor unit to be fitted with the technology. It also wouldn't detect when a trailer remained attached but had a load added or removed, unless there was also equipment attached to the fifth wheel which could detect the change in weight and prompt the satnav system to demand reconfiguration.

There needs to be a multi-pronged approach to dealing with the problem. Improved signage will help but won't prevent every strike. Improved training likewise. Greater penalties for incidents too will have an impact. Improved technology also has a role to play, but none of these things will happen overnight.

I would imagine that the satnav could watch the trailer electrics connection or the tractor's air supply or some other surrogate and then react to the thing which reveals a new connection.

At the simplest it might only need to flag up an alert asking whether the height needed resetting, or it could interface with the gearbox or handbrake or whatever to prevent movement until a reset or "no need" is confirmed.

 

[norbitonflyer]

Five in a few months, and four in a single month, suggests something has changed. Has there been a change in the local road network, resulting in more traffic going that way, or changes in sightlines? Or something as simple as a missing sign, or the road having been resurfaced?

 

[Furrysquid]

Five in a few months, and four in a single month, suggests something has changed. Has there been a change in the local road network, resulting in more traffic going that way, or changes in sightlines? Or something as simple as a missing sign, or the road having been resurfaced?

It used to have overheight detection equipment, and the sensors are still there, but, going back through historical views in google streetview, the illuminated sign that tells you if you've activated the sensor was removed sometime between October 2015 and May 2016.

So, not a recent change, but a some point in the past it was considered worthwhile to have the equipment there.

 

[Peter Sarf]

Five in a few months, and four in a single month, suggests something has changed. Has there been a change in the local road network, resulting in more traffic going that way, or changes in sightlines? Or something as simple as a missing sign, or the road having been resurfaced?

Maybe even an update to SatNav data has lost the height of the bridge.

 

[D6130]

That was going to be my point.

Are these not being installed because of the cost, given that with England's extensive rail network there must be at a bare minimum hundreds of rail over road bridges, if not in the low thousands?

They wouldn't be required at every bridge.....just at the small minority of bridges that are lower than the standard double-decker bus or HGV height.

 

[43066]

They wouldn't be required at every bridge.....just at the small minority of bridges that are lower than the standard double-decker bus or HGV height.

I suspect the issue will be who pays for it. Local councils are unlikely to want to, and neither are Network Rail.

 

[Haywain]

Are these not being installed because of the cost, given that with England's extensive rail network there must be at a bare minimum hundreds of rail over road bridges, if not in the low thousands?

There are also matters of planning constraints and adding obstructions to the public highway. There was a good explanation of how complex this is a few years ago but I can't remember the details or where I read it.

 

[norbitonflyer]

Nevertheless, i would hope that the drivers concerned are being asked about how they came to be going that way.
To misquote Lady Bracknell, one bridge strike may be a misfortune, two looks like carelessness - and five suggests it is rather more than mere coincidence.

Whether the drivers are at fault or not, we should be looking in to measures to ensure yet more drivers don't make the same error.

 

[Senex]

Whether the drivers are at fault or not, we should be looking in to measures to ensure yet more drivers don't make the same error.

If a bridge is properly signed (and the measurements are correct), can the driver ever NOT be at fault?

 

[Indigo Soup]

If a bridge is properly signed (and the measurements are correct), can the driver ever NOT be at fault?

Swiss cheese theory. An accident requires multiple failures. Clearly, drivers will sometimes fail to notice signs. That's one failure. What are the other failures that allow the accident to happen?

The railway equivalent would be 'if a signal is working correctly, can a driver ever not be at fault for a SPAD?'

One simple approach to solving bridge strikes would be to close all bridges under railways that don't have 5.03 metres of clearance across the full width of the roadway. This would be intolerably expensive, because the highway authorities would insist on alternative routes being provided at the railway's expense. But it could, in principle, be done.

 

[Haywain]

Clearly, drivers will sometimes fail to notice signs. That's one failure.

How many missed signs is one failure?

The railway equivalent would be 'if a signal is working correctly, can a driver ever not be at fault for a SPAD?'

The driver being at fault is pretty much the default assumption, until there is evidence to the contrary. This is why train driving standards are so high.

 

[Indigo Soup]

How many missed signs is one failure?

One. But there are (or should be) other measures.

Each of those arrows is one lorry that might hit a bridge. The driver seeing the sign and stopping is one of the slices of cheese. I've yet to be convinced that any others consistently exist.

The driver being at fault is pretty much the default assumption, until there is evidence to the contrary. This is why train driving standards are so high.

The railway has also gone to great lengths to make sure that that is a good assumption - in the model above, there are plenty more slices of cheese. TPWS would be one such measure.

I don't disagree that road driver standards do need to be higher. But the road industry also needs to stop relying on 'blame the driver' as the solution to everything.

 

[bishdunster]

One. But there are (or should be) other measures.

Each of those arrows is one lorry that might hit a bridge. The driver seeing the sign and stopping is one of the slices of cheese. I've yet to be convinced that any others consistently exist.

The railway has also gone to great lengths to make sure that that is a good assumption - in the model above, there are plenty more slices of cheese. TPWS would be one such measure.

I don't disagree that road driver standards do need to be higher. But the road industry also needs to stop relying on 'blame the driver' as the solution to everything.

Err, but ultimately it's the individual driver who causes the bridge strike, ergo,
what more can the operators do??????

 

[43066]

Err, but ultimately it's the individual driver who causes the bridge strike, ergo,
what more can the operators do??????

I think the point being made is that the driver is one (fallible) part of the overall “system”. You need to expect that drivers as human beings will sometimes make mistakes, so just saying “it’s the driver’s fault”, while true, isn’t especially helpful in reducing bridge strikes.

The question is what else you can introduce as mitigate the risk: from rebuilding the railway/road network so that low bridges no longer exist in the first place; better satnavs; better driver training and metal structures built in front of low bridges are all possible solutions.

Some measures will be more effective than others, but the only ones they will be totally fool proof will likely be too expensive/impractical.

 

[Haywain]

The driver seeing the sign and stopping is one of the slices of cheese. I've yet to be convinced that any others consistently exist.

Well, almost all low bridges have multiple signs, then there's appropriate sat-navs, and knowing the height of the vehicle and trailer or load. All of these appear to be the driver's responsibility. That's a lot of cheese slices

 

[Titfield]

I think the point being made is that the driver is one (fallible) part of the overall “system”. You need to expect that drivers as human beings will sometimes make mistakes, so just saying “it’s the driver’s fault”, while true, isn’t especially helpful in reducing bridge strikes.

The question is what else you can introduce as mitigate the risk: from rebuilding the railway/road network so that low bridges no longer exist in the first place; better satnavs; better driver training and metal structures built in front of low bridges are all possible solutions.

Some measures will be more effective than others, but the only ones they will be totally fool proof will likely be too expensive/impractical.

Well, almost all low bridges have multiple signs, then there's appropriate sat-navs, and knowing the height of the vehicle and trailer or load. All of these appear to be the driver's responsibility. That's a lot of cheese slices

As I have said before and upthread, the question that needs answering is why do drivers ignore the warnings; they see the signs, they know they are in a high vehicle.

What causes the brain to fail to process this data correctly so that they stop?

To me this has parallels to the Moorgate Tube disaster where the driver just didnt stop but ploughed into the end wall. There are numerous train crashes where the driver just fails to react as expected given the information (warnings visual and audible) that are given.

 

[Haywain]

The question is what else you can introduce as mitigate the risk:

But that is a different question from "who is responsible?"

 

[43066]

As I have said before and upthread, the question that needs answering is why do drivers ignore the warnings; they see the signs, they know they are in a high vehicle.

Because they are distracted/tired/following the wrong mental model, ie they think they’re in a lower vehicle. None of this is surprising or unknown - in fact it has been researched for decades, just look up “human factors”, or “non technical skills”.

To me this has parallels to the Moorgate Tube disaster where the driver just didnt stop but ploughed into the end wall. There are numerous train crashes where the driver just fails to react as expected given the information (warnings visual and audible) that are given.

I’m not sure that’s a good parallel at all for various reasons - it’s fairly likely he had some kind of medical emergency, and there was no system in place to prevent the train driving into the tunnel and crashing into the buffers at speed.

There are numerous train crashes where the driver just fails to react as expected given the information (warnings visual and audible) that are given.

Very few serious crashes these days but that’s largely because of TPWS, which prevents a good number of the severe ones, and if that system were removed you’d see more. There are still quite a few SPADs despite the high level of train driver training and emphasis on non technical skills.

But that is a different question from "who is responsible?"

But, as I said in the paragraph above the sentence you quoted, the more relevant question is how do we change things to reduce accidents? Just saying “it’s the driver’s fault” doesn’t really move the discussion on much in terms of improving safety, and certainly isn’t the approach taken by the railway or the airline industry.

 

[Haywain]

Just saying “it’s the driver’s fault” doesn’t really move the discussion on much in terms of improving safety, and certainly isn’t the approach taken by the railway or the airline industry.

That's true but the problem is that it doesn't appear that the road haulage industry sees it as a problem that they have to address.

 

[43066]

That's true but the problem is that it doesn't appear that the road haulage industry sees it as a problem that they have to address.

Well things won’t improve until they do - that is the point myself and others have made.

It’s pretty clear that painting bridges and putting up signs isn’t a solution, and neither is simply blaming and punishing drivers.

 

[PyrahnaRanger]

so how about making the use of a suitable professional satnav absolutely mandatory? I can't understand why it is not - and coming from a railway perspective, I don't see why they shouldn't interface with the truck engine as well and cut it out if a conflict is imminent.

This sounds like a good idea, but I suspect the reality would be less so for a couple of reasons: my car is fitted with a hazard detection camera, which seems to work by detecting things in front of the car and doing nothing about it, then going into a blind panic on an open road, with no traffic or obstructions, and then slamming the brakes on. I'm sure Audi meant well, but like a lot of their ideas, the implementation is a bit dodgy. The other reason is: it's making an already complex canbus system even more complex if it has to take input from multiple different sat navs, or are you thinking each HGV has an inbuilt one? Also, what happens if there's no GPS, or is a poor fix? It's also a potential security hole, and car makers haven't really got their head around this yet.

The problem as I see it with very low bridges like that is that van drivers presumably don't encounter many bridges that are too low for them to pass under, and no amount of safety features could eliminate these incidents beyond closing the road entirely. It's probably best to do what's been done at my local bridge - put huge protection beams across the carriageway and at least the trains can run and the pedestrians get through.

Possibly also caused by those vans being used a lot by people driving them on just a car licence - I'd you've never driven anything taller than an astra, low bridges probably never enter your head - especially driving some more modern vans, they really do handle like a car!

How hard is it for drivers to pay attention to warnings? How do people keep getting it so wrong?

Well... Yes. Two overspeed incidents at Spital Junction, how do people keep getting it so wrong when there are warnings telling them what's happening? Oh, except the railway has two proper investigations into why that happened, but instead of being given the benefit of the doubt, there's a distinct feeling some people here would quite happily send these truckers to the gallows!

surely a driver can be mandated to reset the height after each trailer change? Or the satnav itself might be able to read when a trailer has been attached and require a new height input?

You can mandate as much as you want, but that won't stop someone forgetting. Like many things that become rote behaviours, you'll struggle to remember if you've done it or not. What about if there's no trailer to attach and reattach? Say a 17 ton flatbed? Or what happens if it's a trailer with a ramp, and you have different vehicles on the back without disconnecting the trailer?

It must be possible (e.g.) to get a lorry system to recognise that the trailer air supply (or the electrics) has been broken and to then insist on a new height input after reconnection.

Possible, yes. But only if it takes place. And if it's an integrated sat nav, don't expect it to be able to tell Google maps or Waze anytime soon.

As I have said before and upthread, the question that needs answering is why do drivers ignore the warnings; they see the signs, they know they are in a high vehicle.

What causes the brain to fail to process this data correctly so that they stop?

Exactly. Unfortunately, the police and the insurance companies aren't interested in this, they only want to know who is to blame so they can prosecute or send them a bill. RAIB have noted attentional blindness in multiple reports, but there isn't really an independent, non-blame apportioning body to investigate road accidents. Maybe in this case, there is something else that is capturing focus, like a bus stop or a road sign or those trees you need to avoid with your mirrors, and by the time you've dealt with that, you're looking beyond the bridge, not at it...

 

[Peter Sarf]

Well things won’t improve until they do - that is the point myself and others have made.

It’s pretty clear that painting bridges and putting up signs isn’t a solution, and neither is simply blaming and punishing drivers.

I would be interested to know how many things other than low railway bridges the haulage industry bashes.
This might help to form a picture is it :-
Distraction,
Confusion,
Forgetfulness.

In the case of a van bashing a bridge I suspect it could often be an inexperienced (ie car) driver. Most vans are too soft to move a bridge so maybe not too serious.

Back in about 1985 a lorry with a crane on the back took out a bridge on the A2 at Cobham golf course. That is a dual carriageway with three lanes in each direction. Brought the concrete deck down in one complete 400 tonne (apparently) slab !. I do not think driver error or SatNav logging a change in trailer would have influenced it.

If I remember correctly the boom of the crane had become dislodged. But there was a theory the bridge had become too low after the road level was changed. In both possible cases a warning system as part of the bridge would have helped. But a system on the lorry would have been oblivious.

This leads me to the question - How many vulnerable bridges are there and how many vehicle are considered a risk.
It occurs to me that warning systems on vulnerable bridges would require far fewer installations than if installed on all risky vehicles.

The problem is, unfortunately, obviously not considered serious enough to justify the expense.

 

[PG]

RAIB have noted attentional blindness in multiple reports, but there isn't really an independent, non-blame apportioning body to investigate road accidents.

I have a vague recollection of something akin to RAIB but for roads being mooted a couple of years back. Doubtless shelved when it came down to funding.

Maybe in this case, there is something else that is capturing focus, like a bus stop or a road sign or those trees you need to avoid with your mirrors, and by the time you've dealt with that, you're looking beyond the bridge, not at it...

Exactly this. Now we're getting somewhere...

 

[edwin_m]

In the case of a van bashing a bridge I suspect it could often be an inexperienced (ie car) driver. Most vans are too soft to move a bridge so maybe not too serious.

Back in about 1985 a lorry with a crane on the back took out a bridge on the A2 at Cobham golf course.

Most of the tallest trucks and double-deck buses are pretty soft as well. Those with a more solid structure, such as tipper trucks and tankers, are lower due to weight limits so will fit under most of the problem bridges.

Heavy plant on a flatbed is a potential exception. On the locally notorious A606 bridge at Keyworth some years back, the arm of an excavator being transported hit the bridge and swung round into the side of a passing bus.

 

[norbitonflyer]

Each of those arrows is one lorry that might hit a bridge. The driver seeing the sign and stopping is one of the slices of cheese.

No -
the presence of the sign is one slice.
the accuracy of the sign is another
the visibility/prominence of the sign is another
the presence of audible or visual warnings triggered by overheight is another
the use of satnav is another
the driver knowing/remembering the height of the lorry is another
the local knowledge of the driver is another
the concentration/lack of distraction of the driver is another.
legal or financial sanctions against the driver is another

Not all slices may be present The size of the holes in each slice are the likelihood of a failure (sign missing/driver forgetting etc). The rate at which accidents happen is a function of the number of slices and the sizes of the holes in those slices.

However culpable the individual drivers are, none of them set out to hit a bridge. People are fallible, and if you want to stop bridges being hit, you have to make the system foolproof. Clearly a bridge that is hit four times in a month is not foolproof (and/or is on a road that is used by a lot of fools)

The question remains as to why there has been a sudden increase in strikes. has the signage changed? has the local road layout changed - either permamently or temporary? is there some local development in the area that has resulted in more HGV traffic? (construction project, new warehouse business opening)

 

[Indigo Soup]

Well things won’t improve until they do - that is the point myself and others have made.

It’s pretty clear that painting bridges and putting up signs isn’t a solution, and neither is simply blaming and punishing drivers.

Precisely this. Notably, RAIB (and its Air and Marine equivalents) also have a remit to investigate near misses. A culture has been carefully created that enables everyone who works on the railway to say 'crikey, that was close - better report it so it doesn't happen next time'.

The road culture of attaching all blame to the driver results in 'crikey, that was close - better keep quiet else I'm out of a job'. So we don't know about all the times that a bridge was nearly hit, or that a tree was taken out, or a sharp-eyed site manager stopped a lorry that had been incorrectly loaded.

I have a vague recollection of something akin to RAIB but for roads being mooted a couple of years back. Doubtless shelved when it came down to funding.

Road Safety Investigation Branch, because the pressure groups have successfully convinced people that calling things 'accidents' means you're not adequately blaming anyone. Suspect it never went anywhere because it might recommend doing things that would involve spending money.

== Doublepost prevention - post automatically merged: 29 Jan 2025 ==

However culpable the individual drivers are, none of them set out to hit a bridge. People are fallible, and if you want to stop bridges being hit, you have to make the system foolproof. Clearly a bridge that is hit four times in a month is not foolproof (and/or is on a road that is used by a lot of fools)

Absolutely - and the evidence seems to be that a safety management system based around 'put up signs and rely on drivers seeing them' doesn't work. If we want to reduce the number of bridge strikes, we clearly need to try another approach.

 

[norbitonflyer]

Possibly also caused by those vans being used a lot by people driving them on just a car licence - I'd you've never driven anything taller than an astra, low bridges probably never enter your head - especially driving some more modern vans, they really do handle like a car!

People also forget that they have a roof load - a friend did serious damage to the roof of his car that way, as well as to two very expensive bicycles.

I do wonder if a factor is the trend towards lorries with lower cabs, with the driver forward of, instead of above, the engine - designed in the interests of cyclist and pedestrian safety - meaning the bridge span is further from the driver's eye line.

== Doublepost prevention - post automatically merged: 29 Jan 2025 ==

Road Safety Investigation Branch, because the pressure groups have successfully convinced people that calling things 'accidents' means you're not adequately blaming anyone.

Indeed. The suggestion that "there is no such thing as an accident" is an abuse of language. It implies that every crash is deliberate, in which case all preventative measures, from warning signs to speed awareness courses, are nugatory (not to mention insurance), and that every fatal incident is either suicide or murder.

 

[Indigo Soup]

Indeed. The suggestion that "there is no such thing as an accident" is an abuse of language. It implies that every crash is deliberate, in which case all preventative measures, from warning signs to speed awareness courses, are nugatory (not to mention insurance), and that every fatal incident is either suicide or murder.

It's based on a gross misinterpretation of 'accident' as meaning 'nothing could be done, it's just one of those things that happens'. The preferred term now is apparently 'crash' or 'collision'.

There are of course plenty of accidents that don't involve a collision, and not a few collisions that aren't accidental.

 

[RGM654]

Well, almost all low bridges have multiple signs, then there's appropriate sat-navs, and knowing the height of the vehicle and trailer or load. All of these appear to be the driver's responsibility. That's a lot of cheese slices

Those are not fully independent cheese slices because there is a common point of failure, the driver's attention. In the absence of some sort of automatic system involving the vehicle's brakes, sat nav, etc as discussed above, drivers have total control of their vehicles. If
they choose to drive one straight into a tree or a bridge there is nothing to stop them. A physical barrier just before the bridge, as has been installed in some places, results in the same amount of damage to the vehicle (or its load) and the same amount of debris on the road (so no worse than actually hitting the bridge) but does at least leave the bridge itself unscathed.