Driving standards

[Reorte]

27 minutes ago, caradoc said:

 

But does it ? Is it not just as likely to cause the unexplained slowing-downs seen on the motorways, where one vehicle brakes due to going faster than anything else, and other drivers react by braking too, so the traffic flow progressively gets ever slower ?

 

AIUI it depends just how busy the motorway is in the first place. When it's close to capacity that can happen; it can happen even below the speed limit (indeed that's more likely when the traffic is very heavy but it's still flowing reasonably well). Under those conditions slowing everyone down further helps keep it flowing; at least that's the theory behind variable speed limits. On the other hand when it's not quite there I believe (i.e. I'm sure I read it somewhere once but I may be imagining things too) it helps if those brief blockages can clear more quickly, e.g. not having two slower than average vehicles passing with a minor speed differential. The dynamics of traffic flows are pretty interesting (if you're in to that sort of thing).

[Jol Wilkinson]

6 hours ago, caradoc said:

 

I disagree; Not limiting vehicles to 70mph gives anyone the freedom to break the law and speed, whether or not is safe (or rather, less unsafe) and regardless of their ability to drive fast, or of others to appreciate and react to their speed.

When I took London Road to Scaleforum in September 2019, the Transit hire van was fitted with a speed limiter, effective at an indicated 62mph. Driving at that speed on the A14, A12, M25 and A40 dual carriageways was not a problem per se until you needed to overtake someone driving at 60mph or a little slower. Avery frustrating situation and not one that makes for a comfortable, stress free,  journey

 

In theory if everybody drove at 60mph, 70mph or whatever the relevant speed limit is, then it wouldn't be a problem - assuming all drivers are awake, paying attention, not using the phone, being distracted by the kids, etc. But if someone is driving a bit slower because they want to do so, then it would be a cause of  annoyance to many. 

[caradoc]

But not everyone drives at the same speed now ! We have already discussed, in this topic, HGVs limited to 56mph, and as above, vans limited to 62mph. And there will always be those who do not wish to drive at the maximum motorway speed, even if their vehicle is perfectly capable. So even with vehicles fitted with 70mph-limiters there will still be varied traffic speeds. BTW I would not suggest for one moment that all vehicles should be retro-fitted, rather that it should at least be considered for new build; Although, as mentioned above, average speed cameras at the worst locations are cheaper and more effective, at least in the short term.

[PaulCheffus]

22 minutes ago, caradoc said:

But not everyone drives at the same speed now ! We have already discussed, in this topic, HGVs limited to 56mph, and as above, vans limited to 62mph. And there will always be those who do not wish to drive at the maximum motorway speed, even if their vehicle is perfectly capable. So even with vehicles fitted with 70mph-limiters there will still be varied traffic speeds. BTW I would not suggest for one moment that all vehicles should be retro-fitted, rather that it should at least be considered for new build; Although, as mentioned above, average speed cameras at the worst locations are cheaper and more effective, at least in the short term.

Hi

 

What happens then when one of the unrestricted vehicles drives along at 40 in a 60 so you go to overtaken in your restricted vehicle and they decide to speed up. You then have to pull back in behind them because you are unable to complete the manoeuvre which in itself can be dangerous.

 

Cheers

 

Paul

Edited January 6, 2020 by PaulCheffus

[caradoc]

True, but that is down to stupid driver behaviour (of the vehicle being overtaken), nothing else.

 

[Reorte]

49 minutes ago, caradoc said:

True, but that is down to stupid driver behaviour (of the vehicle being overtaken), nothing else.

 

Nearly all the problems we've currently got on the roads (beyond sheer congestion) are down to stupid behaviour from a relatively small percentage of drivers (whilst a large number might not be great they're generally not awful either, there are so many vehicles on the road though that even a small number of bad drivers is quite noticeable).

[Enterprisingwestern]

9 hours ago, caradoc said:

But not everyone drives at the same speed now ! We have already discussed, in this topic, HGVs limited to 56mph, and as above, vans limited to 62mph. And there will always be those who do not wish to drive at the maximum motorway speed, even if their vehicle is perfectly capable. So even with vehicles fitted with 70mph-limiters there will still be varied traffic speeds. BTW I would not suggest for one moment that all vehicles should be retro-fitted, rather that it should at least be considered for new build; Although, as mentioned above, average speed cameras at the worst locations are cheaper and more effective, at least in the short term.

 

It's a great idea in theory, but unless every vehicle is fitted with a limiter overnight it can't possibly work, there will be two classes of motorist.

 Edit. Thinking about it, speed cameras are speed limiters in theory, just not constantly, and look how well they work!

 

Mike.

Edited January 7, 2020 by Enterprisingwestern

[rockershovel]

One thing that I did learn in Lincolnshire, a county with long stretches of road fitted with “average speed” cameras yet having the worst traffic accident stats in the country, is that they create their own categories of accidents. Drivers speeding through local speed restrictions, for one. Lapses in concentration.

 

Another problem is vehicles which are registered to persons no longer locally resident, typically transients of various descriptions. This effectively places them outside the “speed camera” regime, since statutory penalties are never received or paid, and the police have two options; stop the vehicle, impound the vehicle and arrest the driver, or turn a blind eye. Note that the law does not provide the option of arrest and impoundment in all cases. You might speculate on the effects of this; I routinely saw vehicles being driven at very high speed and executing wild overtaking manouvres on the A16. 

 

Edited January 7, 2020 by rockershovel

[caradoc]

Perhaps anyone caught driving at very high speed should in future only be permitted to drive a speed-limited vehicle ? (Although like so many other road laws, it would be difficult if not impossible to police).

[kevinlms]

26 minutes ago, caradoc said:

Perhaps anyone caught driving at very high speed should in future only be permitted to drive a speed-limited vehicle ? (Although like so many other road laws, it would be difficult if not impossible to police).

Speed limited? But in what way an overall top speed, or one that takes local speed limits into account? I guess the latter is coming closer to being possible - GPS or Google Maps?

 

But in principle I don't disagree with you. Take a look at Victoria's penalties for drink driving.

 

https://www.vicroads.vic.gov.au/safety-and-road-rules/road-rules/penalties/drink-driving-penalties

 

Can't see why there is a difference between DD & excessive speeding, personally.

[Reorte]

3 minutes ago, kevinlms said:

Can't see why there is a difference between DD & excessive speeding, personally.

 

What is excessive speeding is rather harder to pin down with certainty. Whilst you can say "x above the limit" that's somewhat arbitrary; it's necessary to have a known, fixed legal limit but just how bad going over it is very much depends on the specific circumstances of the time and place. Drunk driving is just plain outright dangerous whatever the circumstances though.

 

I like the idea of restrictions being restricted themselves to those who demonstrate that they're unfit to do anything without someone watching over their shoulder all the time though.

[Nick C]

51 minutes ago, kevinlms said:

... or one that takes local speed limits into account? I guess the latter is coming closer to being possible - GPS or Google Maps?

 

That's a really scary prospect - I know of several places where two roads, with different speed limits, run closely parallel (or even one above the other). All it needs is for the GPS to drift a little (e.g. passing through trees, or a busy urban area, causing reception to drop) and the limiter suddenly thinks you're on the 30mph local road instead of the 70mph motorway...

[kevinlms]

1 minute ago, Nick C said:

 

That's a really scary prospect - I know of several places where two roads, with different speed limits, run closely parallel (or even one above the other). All it needs is for the GPS to drift a little (e.g. passing through trees, or a busy urban area, causing reception to drop) and the limiter suddenly thinks you're on the 30mph local road instead of the 70mph motorway...

Never had that sort of thing happen on GMs.

The closest I'm come is that I'm on a 3 lanes each way road waiting at lights (front of queue). It suddenly suggests I turn left, go 300 metres up the road, chuck a Uey, come back and turn left again.

 

Nargh, I think I'll wait for the lights to change! 

[rockershovel]

5 minutes ago, Nick C said:

 

That's a really scary prospect - I know of several places where two roads, with different speed limits, run closely parallel (or even one above the other). All it needs is for the GPS to drift a little (e.g. passing through trees, or a busy urban area, causing reception to drop) and the limiter suddenly thinks you're on the 30mph local road instead of the 70mph motorway...

 

Which is quite a good question, actually. The resolution of a satnav is about 3-5 metres, and it uses its pre-existing data to place the image in the appropriate lane. You can see this operating any time you drive through a local lane diversion or contraflow, where the data map doesn’t match its observed position...

 

[Nick C]

5 minutes ago, rockershovel said:

 

Which is quite a good question, actually. The resolution of a satnav is about 3-5 metres, and it uses its pre-existing data to place the image in the appropriate lane. You can see this operating any time you drive through a local lane diversion or contraflow, where the data map doesn’t match its observed position...

 

They're a lot better than they used to be, but I've still seen enough errors that I wouldn't want them used for enforcement. If I switch mine on in our office car park it thinks I'm on the M3...

[JDW]

13 hours ago, PaulCheffus said:

What happens then when one of the unrestricted vehicles drives along at 40 in a 60 so you go to overtaken in your restricted vehicle and they decide to speed up. You then have to pull back in behind them because you are unable to complete the manoeuvre which in itself can be dangerous.

Cheers

Paul

 

This happens day in, day out to commercial drivers anyway. Try driving a coach on the limiter at 62 (actually, use the cruise control, much better than trying to hold it on the limiter...) and see how often you gradually catch a car, pull out, get alongside, they speed up, pull away, slow down again,...

 

9 minutes ago, Nick C said:

That's a really scary prospect - I know of several places where two roads, with different speed limits, run closely parallel (or even one above the other). All it needs is for the GPS to drift a little (e.g. passing through trees, or a busy urban area, causing reception to drop) and the limiter suddenly thinks you're on the 30mph local road instead of the 70mph motorway...

 

One of the things we had happen with our tracking softeware where I worked was similar, although it tended to have the opposite effect as a brief loss of gps or interruption would then make the bus look like it was still in the same place for a minute or so, then reappear somewhere else, having apparently gotten there at 120mph. Obviously, it only happened on rare occasaions, and it was usually pretty obvious that it was a system error (one of our vehicles once showed up on a map as being in Israel...), but as you say it would make me wary of trusting any such system to be 100% accurate, especially in a private car environment, where there is no "back-up" to prove the error in the same way that a bus driver has timetables, CCTV, etc, that can show what actually happened.

 

[Reorte]

6 minutes ago, rockershovel said:

 

Which is quite a good question, actually. The resolution of a satnav is about 3-5 metres, and it uses its pre-existing data to place the image in the appropriate lane. You can see this operating any time you drive through a local lane diversion or contraflow, where the data map doesn’t match its observed position...

 

I can see contraflows confusing it but a diversion shouldn't; a satnav should take into account where you've turned and where turnings actually are as well as the GPS-derived location to determine which road you're on. I've noticed this in the built in one in my car (which hasn't been updated for years), where a road has been diverted since the map was drawn it takes some time to stop snapping to the road, and when it thinks you're driving across fields (in reality on a road it doesn't know about) it will snap to the nearest road it knows about if you're close to one. An up-to-date system shouldn't have problems - I don't see any real technical barriers to such a concept (hate the idea though).

[PaulCheffus]

42 minutes ago, rockershovel said:

 

Which is quite a good question, actually. The resolution of a satnav is about 3-5 metres, and it uses its pre-existing data to place the image in the appropriate lane. You can see this operating any time you drive through a local lane diversion or contraflow, where the data map doesn’t match its observed position...

 

Hi

 

My car displays the speed limit as an icon in the driver information window which gets its information from the SAT Nav or by reading the road signs.

 

On Sunday I was travelling in a 40mph zone when suddenly the car showed the speed limit as 60mph ( there was no change in the road sign so this must have come from the SAT Nav). As far as I am aware the road I was on has always been 40mph at that point. A couple of seconds later it reverted back to 40mph. For avoidance of doubt I continued at 40mph.

 

Cheers

 

Paul

[PhilJ W]

Thats why I don't trust prat-navs.

 

[rockershovel]

54 minutes ago, Reorte said:

 

I can see contraflows confusing it but a diversion shouldn't; a satnav should take into account where you've turned and where turnings actually are as well as the GPS-derived location to determine which road you're on. I've noticed this in the built in one in my car (which hasn't been updated for years), where a road has been diverted since the map was drawn it takes some time to stop snapping to the road, and when it thinks you're driving across fields (in reality on a road it doesn't know about) it will snap to the nearest road it knows about if you're close to one. An up-to-date system shouldn't have problems - I don't see any real technical barriers to such a concept (hate the idea though).

 

I notice it locally on the Southbound A1M South of Peterborough, where a long section of the former A1 remains in use as a local road, immediately East of the A1M - the satnav appears unable to differentiate between the two roads. It can also be seen if you drive past a predicted exit, for example on the latest iteration of the A14, where the exit from the S bound A1 has been superseded - it shows the car driving halfway up the sliproad, before snapping back to the A1M

 

[ejstubbs]

Regarding whether or not compulsory speed limiters should be introduced, it seems that some folks may have forgotten this from March last year:

 

Quote

 

Speed limiting technology looks set to become mandatory for all vehicles sold in Europe from 2022, after new rules were provisionally agreed by the EU.

 

The Department for Transport said the system would also apply in the UK, despite Brexit.

 

 

1 hour ago, Nick C said:

I know of several places where two roads, with different speed limits, run closely parallel (or even one above the other). All it needs is for the GPS to drift a little (e.g. passing through trees, or a busy urban area, causing reception to drop) and the limiter suddenly thinks you're on the 30mph local road instead of the 70mph motorway...

 

If assisted GPS is regarded as good enough for autonomous cars to navigate themselves (which is seems to be - it's the algorithms that deal with changing road conditions, especially collision avoidance and the like that seem to be less easy to get right) then I suspect the location algorithms are already - or soon will be - accurate enough for speed limiters to be reliable.

 

2 hours ago, Reorte said:

What is excessive speeding is rather harder to pin down with certainty. Whilst you can say "x above the limit" that's somewhat arbitrary; it's necessary to have a known, fixed legal limit but just how bad going over it is very much depends on the specific circumstances of the time and place.

 

It doesn't really matter, though, does it?  Exceeding the limit is against the law, and it's quite usual for the perceived severity of the infraction to be taken in to account when assessing the penalty.  We don't hang anyone who steals a loaf of bread these days, but steal a lorry load of stuff and you'll be looking at rather stiffer sentence then if you just shoplift one item.

 

You could (and people do) argue that the blood alcohol limit is 'arbitrary' - it's recognised that the effect of alcohol on decision making, judgement, speed perception and the like varies between individuals.  In Scotland the limit is lower than in the rest of the UK: you could be driving through Cornhill on Tweed with a legal blood alcohol level, and then be 59% over the limit when you cross the bridge in to Coldstream.  That sounds pretty arbitrary to me.

 

For the average person (which is what you have to legislate for), it's pretty much impossible to say what the "safe" blood alcohol level is for driving, or even if there is one.  Russia amongst other countries supposedly has a zero tolerance policy (though you wouldn't know it looking at all the Russian dashcam accident footage on Youtube).  In the US it varies by state.  There is little consistency.  The point is that pretty much everyone agrees that the average person is incapable of assessing their own fitness to drive due to alcohol, so the safest approach is just not to do it.  Laws are therefore put in place to discourage such behaviour - the fact that the limits vary are more to do with different approaches to enforcement, accommodation of edge cases, and local perceptions of the severity of the problem and the acceptable degree of leeway that should be allowed.

 

My own view is that most drivers are pretty poor at managing their own vehicle's speed under varying road conditions.  The analogy with drunk driving is therefore valid IMO: the majority of people are not very good at assessing how badly alcohol affects their own driving, or what is actually a safe speed for any particular combination of road conditions, so fixed limits ('arbitrary' if you will) are used to set a baseline standard of behaviour which, through the legislative process, is assessed as being likely to achieve the best balance between effectiveness and intrusiveness in reducing the overall risk to all road users (in particular the innocent victims of others people's urges to treat public roads like a racetrack).

 

It seems to me that most cases where someone would otherwise have been disqualified from driving due to totting up, or a single instance of egregiously excessive speed, tend to be successfully argued on the basis of the hardship that loss of the licence would cause, not the view that it was actually safe to exceed the speed limit at the time of the offence.  With most speed limit enforcement being automated these days, there's much less scope for the sort of leniency that could be offered by the bobby who pulled you over for doing 90mph on the motorway at 3am but let you off with a warning because you were polite and there was no-one else around.  In such a regime, and with ever increasing volumes of traffic and fewer and fewer police officers on the roads, the attraction of mechanisms to reduce people's ability to break the law in the first place are pretty obvious.

 

(My understanding, by the way, is that the police use the term "excessive speed" specifically to mean a speed in excess of the speed limit, not a speed which was unsafe in the prevailing road and traffic conditions.  A bit like the use of "collision" rather than "accident", except in this case I think the result can be confusing if people think that "their speed was not excessive" means "they were not travelling at an unsafe speed".)

Edited January 7, 2020 by ejstubbs

[dvdlcs]

Between 1997 and 2008, I lived in the Cambridge area. I drove back and forth to visit relatives in Scotland. It was a fairly simple trip: A14 and A1, follow your nose.

 

Cruise Control: When I purchased a car with CC fitted (2001?) I used it on these long (~350 mile) trips and it was a godsend. It also highlighted just how erratic other peoples speeds were. The classic was overtaking something going up the hill and then having them pass me coming down the other side, as my CC was holding the car at 70 whereas inevitably they would slow a little on the up slope and run a little fast coming downhill. Not sure about wear on tyres but it certainly helped the fuel economy.

 

Average Speed Cameras: These were placed on the A14 around Huntingdon and something I noticed, whether on local trips or longer distance runs to and from Scotland was that I would always encounter traffic there. Everybody seemed to bunch up. I could drive hundreds of miles down the A1, even on quiet days (e.g. New Years Day) and have light, well-spaced traffic with the CC on 70, only disengaging for the roundabouts (and that 50 zone, whose name I forget) but as soon as I reached the average speed camera area around Huntingdon I'd run into the back of much denser traffic. Afraid these didn't create a good impression on me for that reason - may not be a good reason, but that was the impression they gave: caused congestion by making (some) people slow down and everybody else bunch up.

[PaulCheffus]

27 minutes ago, ejstubbs said:

Regarding whether or not compulsory speed limiters should be introduced, it seems that some folks may have forgotten this from March last year:

 

Hi

 

From the same site

 

"The system can be overridden temporarily. If a car is overtaking a lorry on a motorway and enters a lower speed-limit area, the driver can push down hard on the accelerator to complete the manoeuvre."

 

"A full on/off switch for the system is also envisaged, but this would lapse every time the vehicle is restarted."

 

"However, there is concern over whether current technology is sufficiently advanced for the system to work effectively."

 

Cheers

 

Paul

 

Edited January 7, 2020 by PaulCheffus

[Nick C]

49 minutes ago, ejstubbs said:

It seems to me that most cases where someone would otherwise have been disqualified from driving due to totting up, or a single instance of egregiously excessive speed, tend to be successfully argued on the basis of the hardship that loss of the licence would cause, not the view that it was actually safe to exceed the speed limit at the time of the offence. 

 

That's one I really do not understand - you keep seeing stories in the news of people who have 20+ points still arguing hardship - IMHO that should only be possible once, then after that, it should be "tough, you should have thought about that before continuing to break the law" - anyone could have the odd lapse of judgement, but when they get caught speeding (or worse) for the 6th or 7th separate time (and they're usually pretty blatant too) there ought to be more punishment...

[rockershovel]

I’d also expect that there was an inverse relationship, between persons most likely to drink and drive, and persons likely to diagnose themselves as unfit to drive?