What an HGV sees of you

[deptfordmarmoset]

Without the help of a blackboard, chalk, and a toy articulated lorry, this is a difficult one to explain!
I am thinking that the loss of sweep wouldn't be too much of a problem, given that the driver has already established that the area which is about to become "blind" has already been seen to be clear, otherwise he wouldn't be continuing with the manoeuvre.
The problem might arise when straightening up again, if someone has been stupid enough to move into the blind area while the lorry was turning. I had this exact situation one night when joining the M8 motorway in Edinburgh, from the city by-pass (A720).
Heavy traffic on a big multi-lane roundabout, and I am going right on the roundabout. Someone lets me into the queue, so I am effectively turning to my left to join the right hand lane for turning right. I couldn't straighten up in the space available before coming to a stop in the traffic, so trailer is sitting about 45 degrees to the left of the tractor unit. Nobber in car thinks he can take advantage and cut into the traffic by coming up the left side of my trailer, about 2 feet from the side of it! What he doesn't think about is how my trailer is going to move to my left as I straighten up, and is going to re-arrange the right side of his car. Luckily I checked my nearside mirrors (as always) before moving off and realised I would have to sit there until nobber realised what he had done. With swivelling mirrors I would only have been able to see him in the blind spot mirror.
Your idea might work better if the main mirror was split into two parts (it is big enough for that) with one half remaining the way it is in one position, and the other half able to swivel outwards and inwards in conjunction with the steering.
We don't want any more mirrors! There are enough distractions already, and mirrors in themselves cause blind spots. They are quite big, and you can't see through them.

Thanks, I'll have to think for a while because I haven't managed to visualise this fully yet.

 

[Brandane]

[QUOTE 2783850, member: 30090"]I don't think what has been described would happen.

If when looking at the unit and trailer combination from behind, the trailer the is at a 45 degree angle to the left, when the trailer straightens out the trailer will move to the right. Although the question is whether there is enough room for the trailer to straighten up without clipping what has gone up the left. So there is that to think about. What you think is room is not when you hit by the trailer wheels.[/quote]
Maybe I haven't described it very well, or underestimated the angles involved, but..... If the angle between tractor and trailer are big enough, then when you move the tractor forward you are obviously pulling the trailer in that direction from the point of the pin, which is located on the underside of the trailer about 10% along its length (the pin being the bit on the trailer which connects with the turntable or fifth wheel on the tractor unit - for non HGV drivers).
In the situation I tried to describe on the roundabout, I was most certainly going to pull the front of the trailer to the left as it straightened up!

 

[deptfordmarmoset]

Maybe I haven't described it very well, or underestimated the angles involved, but..... If the angle between tractor and trailer are big enough, then when you move the tractor forward you are obviously pulling the trailer in that direction from the point of the pin, which is located on the underside of the trailer about 10% along its length (the pin being the bit on the trailer which connects with the turntable or fifth wheel on the tractor unit - for non HGV drivers).
In the situation I tried to describe on the roundabout, I was most certainly going to pull the front of the trailer to the left as it straightened up!

Forgive my nursery school graphics but is this something vaguely like the situation you described? You're entering the roundabout off the southbound carriageway of the A270 and going for the right hand lane for the M8 entrance. You've found a gap to get onto the right lane on the RB and a car has pulled into the gap on your left. So the car driver has effectively pinned you there until it moves off. (I suppose it must have been a little further back and the car was heading for the 3rd lane).

 

[Brandane]

Forgive my nursery school graphics but is this something vaguely like the situation you described? You're entering the roundabout off the southbound carriageway of the A270 and going for the right hand lane for the M8 entrance. You've found a gap to get onto the right lane on the RB and a car has pulled into the gap on your left. So the car driver has effectively pinned you there until it moves off. (I suppose it must have been a little further back and the car was heading for the 3rd lane).
View attachment 32955

Thats more or less the situation, but maybe a bigger angle of bend between cab and trailer as traffic was backed up! The cab was lined up on the right hand lane, so when you move off, it pulls the trailer at an angle to the left before it begins to straighten up.
There was traffic in the third lane, preventing me (and dopey in the car) from joining at less of an angle. Oh, and car driver had moved up the trailer so far that he couldn't move off without reversing first, because the cab was in the way! He was waiting for me to move first, but hadn't thought it out very well.

 

[deptfordmarmoset]

Thats more or less the situation, but maybe a bigger angle of bend between cab and trailer as traffic was backed up! The cab was lined up on the right hand lane, so when you move off, it pulls the trailer at an angle to the left before it begins to straighten up.
There was traffic in the third lane, preventing me (and dopey in the car) from joining at less of an angle. Oh, and car driver had moved up the trailer so far that he couldn't move off without reversing first, because the cab was in the way! He was waiting for me to move first, but hadn't thought it out very well.

Cheers. So it's a frontal version of what I call drag sweep, which I normally associate with the rear axle. The idea of having a swivelling mirror is so that the turning view is pretty much the same as you'd get with the artic going straight ahead. If there were an equal adjustment of the mirror to the angle of the articulation, the field of vision would be altered only by the fact that the mirror would be situated further outboard, i.e. to the left of its straight on position. The field of vision would move in parallel outward. I hadn't appreciated that this movement might be big enough to remove a car from the field of vision. A slightly reduced angle of swivel might cure this - so, say, a 5:4 correspondence* - provided it doesn't remove vision of the rear of the trailer and the immediate stretch of road to the rear of that.

Perhaps the car driver thought the roundabout was some kind of Tetris game, where the idea is to get as many vehicles onto it without going anywhere. What I call a plug - it's a very characteristic style of driving.

*figure plucked out of the air!

EDIT: Oops, I spot a problem. It's exaggerated in the ''diagram'' below because I've represented the mirrors as at right angles. (The diagram was meant to show how the field of vision would only be slightly changed) But as the vehicle articulates, the angle of the mirror to the driver changes and becomes much narrower from the driver's point of view. In the exaggerating diagram, in fact, the mirror face on the turning cab would no longer be visible at all. In a more realistic image, though, the effect would not be that severe because mirrors aren't at right angles to the cab, the effect would also be reduced by changing the ratio from 1:1

 

[deptfordmarmoset]

[QUOTE 2783850, member: 30090"]I don't think what has been described would happen.

If when looking at the unit and trailer combination from behind, the trailer the is at a 45 degree angle to the left, when the trailer straightens out the trailer will move to the right. Although the question is whether there is enough room for the trailer to straighten up without clipping what has gone up the left. So there is that to think about. What you think is room is not when you hit by the trailer wheels.[/quote]
From the kiddie's google illustration, are we talking about the same thing?

 

[deptfordmarmoset]

[QUOTE 2784813, member: 9609"]I know - how about a huge bungee type cable strapped from the front of the cab to the rear of the trailer, then as the truck turns left anybody stupid enough to have ventured into the danger zone will get catapulted out of the way.

On a more serious thought, and getting back to the mirrors - I''m not sure more mirrors is the answer, there is already too much to concentrate on at a busy junctions, you can't look solely in your nearside mirrors and cyclists can arrive into that space in a fraction of a second. Maybe some sort of proximity sensors that could halt the truck or better still educate cyclists in road craft.[/quote]
I'm not talking about extra mirrors, just one that compensates a little for the turning of an artic to reduce the blind spots, specifically the blind spot that cyclists can stray into/get caught in.

 

[deptfordmarmoset]

[QUOTE 2784889, member: 9609"]Yes I appreciate that and it is far from a bad idea. However I guess most of the accidents are not because of blind spots but more because a cyclist has moved into the danger zone after the driver has checked.

How many of the cyclists lorry incidents have been with articulated vehicles - every time I view the images in the press the tippers are rigids - and they don't suffer from the blind spots in the same way articulated vehicles do - which backs up my theory that it is not necessarily a blind spot issue.[/quote]
I appreciate that it's of no use to a non-articulated truck but, spurred on by recent deaths and the original TfL video of a turning artic, there did seem to be a problem that wasn't being looked at. Cyclists were being told to look out for a danger, my response was to say ''Well, what can we do to minimise that danger. I was curious about how turn-sensitive mirrors could be used to reduce blind spots in HGV drivers' opinions. It must have been trialled before because, in my own clumsy non-mechanical kind of way, I reckon I could do a simple mock up using little more than bike cabling and a spring for the mirror. But I haven't found anything out about when it was tried and what the results of the tests were.

As for for the tipper and skip lorries, I've commented on various issues concerning road compliance, assuming safety responsibilities while on the public road, pay-per-load pressures, and rush hour restrictions. And in my head I've been trying to imagine a series of bicycle priority zones on the approach to junctions on regular freight-bearing roads where trucks may not overtake any vehicle, especially bikes, on the approach. A sort of tipper-taming corner-calming feature....
Easy to imagine, difficult to realise when you have no relevant expertise, design skills, etc, etc! If we had any highway engineers on here, I'm sure they could help. But they are curiously absent from here....

 

[PhilDawson8270]

A wide angle cctv camera over the front wheel facing back with a display in the cabin is all that would be needed.

 

[bpsmith]

Is that not part of the point in taking part in discussions on internet forums? Seeing things from a previously unknown perspective and sharing differing levels of knowledge? It is just slightly disappointing when some people rubbish others POV because their heads are stuck firmly in the sand.

Exactly! It's those who don't take any other comments on board that spoil things. Sometimes I am right, sometimes not, but that's where forums come in and do exactly as you state. Some people are just always right it seems. Lol.

 

[deptfordmarmoset]

A wide angle cctv camera over the front wheel facing back with a display in the cabin is all that would be needed.

True enough but it would be yet another thing to look at. And - perhaps this is a prejudice - it would be a less immediate and more distorted representation (wide angle) of what's going on back there. In principle, though, it would be performing the same function.

 

[SquareDaff]

Ultimately at some point it's all about the cyclist taking some responsibility for their own actions instead of trying to shift the blame elsewhere. You can stick as many extra mirrors as you like down the nearside of a lorry but at some point he has to look straight on and down the offside while completing that turn and we all know that that's more than enough time for a cyclist to scoot up near side if he's of a mind to. In a battle between a cyclist and a HGV there's only ever going to be one winner. Keep yourself safe and keep your distance.

 

[MontyVeda]

I don't at all agree that this is the ultimate destination for this discussion. The blame lies elsewhere. Try thinking about how relatives of people who have been killed recently might feel when they read posts like yours.

But we do have a responsibility for our own safety. Blame lies in a number of places, usually all at once... it's not always 'over there'.

 

[deptfordmarmoset]

Ultimately at some point it's all about the cyclist taking some responsibility for their own actions instead of trying to shift the blame elsewhere. You can stick as many extra mirrors as you like down the nearside of a lorry but at some point he has to look straight on and down the offside while completing that turn and we all know that that's more than enough time for a cyclist to scoot up near side if he's of a mind to. In a battle between a cyclist and a HGV there's only ever going to be one winner. Keep yourself safe and keep your distance.

I think the use of ''ultimately'' is unhelpful. It would maybe be more useful to think about it in terms of ''big picture, little picture''. Little picture: when it comes to the cement lorry ahead that isn't indicating at the junction, it doesn't mean that it isn't going to turn. When the truck up ahead at the lights is a little out of lane leaving you an inviting corridor to the lights, it may be out of lane because it's about to turn. In situations like this, sure, your responsibility is towards yourself and your loved ones.

Big picture: ''Here's the thing, folks: we seem to have unleashed a fatal danger onto our streets and we don't have the will to deal with it. This means that you will have to be very, very careful when you're out cycling on the streets. Of course, you might still get killed, even if you take all the necessary precautions, but remember it's Your responsibility to take these precautions.'' That's why the police are out telling cyclists to wear helmets and hi-viz.''

 

[SquareDaff]

I think they'd be quite disgusted that some morally superior trolls would argue that black is white and end up stifling what could be a proper debate. My blunt views might not be to everyones taste but at least they're consistent and I actually give one rather than just argue counter to everyone elses opinion.

I have every sympathy with those people who've lost relatives but unless you're one of those relatives or the person that attended the scene of the accident you have no more idea what happened in those instances than I.

At the start of this thread we had a lorry at a give way junction with a load of bikes up the near side in a "blind spot". Now there's only two ways this is going to happen. Either the cyclists rode up the nearside while the lorry was waiting for a gap in the traffic in which to pull out OR the lorry pulled up the offside of all those cyclists to then deliberately turn left and wipe them all out.

My comment was clearly assuming scenario 1. If you argue with something that much bigger and heavier than you are, whether you're morally right or not, you're going to lose. Leave your ego at home and live to ride another day.