Discussion
Nope, not a typo...
I recon that on any reasonably busy bit of motorway, you'd cause more collisions by driving at 30mph under the current limit than by driving at 30mph over it. Given that the bulk of the traffic is generally moving at more like 80-85 (until the volume of traffic rises to the point where you get compression waves), the speed differential is much greater at 40 than it is at 100. Also, the guy doing 40 is causing the flow to be "turbulent" rather than "laminar" and all the lane switching increases collision risk.
Now, the guy doing 100 is an almost certain pull/zap/points/fine/possible ban etc. The guy doing 40 would certainly escape a scamera. Would he escape the pull by the bib? He's not doing anything technically illegal (I dont think). What would the bib on here do? Pull followed by one way conversation about how much 38 tons up the backside might hurt etc.? Or no stop as nothing illegal?
Just a thought...
I recon that on any reasonably busy bit of motorway, you'd cause more collisions by driving at 30mph under the current limit than by driving at 30mph over it. Given that the bulk of the traffic is generally moving at more like 80-85 (until the volume of traffic rises to the point where you get compression waves), the speed differential is much greater at 40 than it is at 100. Also, the guy doing 40 is causing the flow to be "turbulent" rather than "laminar" and all the lane switching increases collision risk.
Now, the guy doing 100 is an almost certain pull/zap/points/fine/possible ban etc. The guy doing 40 would certainly escape a scamera. Would he escape the pull by the bib? He's not doing anything technically illegal (I dont think). What would the bib on here do? Pull followed by one way conversation about how much 38 tons up the backside might hurt etc.? Or no stop as nothing illegal?
Just a thought...
Couldn`t agree more.
One of the worst things on a motorway is someone who is clearly terrified at the prospect and therefore cruises lane 1 at less than 56mph. They make it worse for themselves because of all the heavies overtaking, and push the slower trucks into lane 2.
Cue a looong line in lane 2.
Steve
One of the worst things on a motorway is someone who is clearly terrified at the prospect and therefore cruises lane 1 at less than 56mph. They make it worse for themselves because of all the heavies overtaking, and push the slower trucks into lane 2.
Cue a looong line in lane 2.
Steve
I have often wondered about writing a paper on the effects on minimum speed limits on various lanes on the motorway.
I think the main problem with this is that the inside lane would need to be the fastest, the outside lane (Lane 3) would be the slowest. This is because of the risk of penetration of the central reserve barrier which is only gauranteed by the manufacturers for collisions up to 70mph.
I do know however, that the major cause of collisions on a motorway is side-swipe. This is why the HA are trialling “No Lane Changes” on some parts of the motorway network in peak hours.
I think the main problem with this is that the inside lane would need to be the fastest, the outside lane (Lane 3) would be the slowest. This is because of the risk of penetration of the central reserve barrier which is only gauranteed by the manufacturers for collisions up to 70mph.
I do know however, that the major cause of collisions on a motorway is side-swipe. This is why the HA are trialling “No Lane Changes” on some parts of the motorway network in peak hours.
Hmmm - I could well be talking b*llocks here, but I seem to remember something about your vehicle must be capable of at least 30mph to take it on the motorway, though I don't remember anthing about actually having to do that.
The reason I chose 40 and 100 is obviously that they are the same differential either side of the motorway limit, but doing a 100 would bring down the weight of the law in a big way (possible ban etc), but I dont know if doing 40 would attract anything at all when *usually* and *in practice* the guy doing 40 is causing more mayhem.
Now, someone doing 100 through slow moving traffic should (in my opionion) attract the attention of the law and invariably will. Someone doing 40 in fast moving traffic may not, but I guess this situation is more likey to happen and does happen very often (how can you do 100 if the bulk of the traffic is slow?) and the effect can be equally serious.
I can't really see how a minimum limit would work in practice though. (Cue image of bib in middle of traffic jam with loud hailer shouting "Oi you lot, you're all nicked!" while the guy in the scamera van is blinded while his flash gun goes into meltdown). If we are not allowed to have bib to police the flow and can only have automated systems instead then we are going to be stuck with only having offences that are easy to detect automatically.
The reason I chose 40 and 100 is obviously that they are the same differential either side of the motorway limit, but doing a 100 would bring down the weight of the law in a big way (possible ban etc), but I dont know if doing 40 would attract anything at all when *usually* and *in practice* the guy doing 40 is causing more mayhem.
Now, someone doing 100 through slow moving traffic should (in my opionion) attract the attention of the law and invariably will. Someone doing 40 in fast moving traffic may not, but I guess this situation is more likey to happen and does happen very often (how can you do 100 if the bulk of the traffic is slow?) and the effect can be equally serious.
I can't really see how a minimum limit would work in practice though. (Cue image of bib in middle of traffic jam with loud hailer shouting "Oi you lot, you're all nicked!" while the guy in the scamera van is blinded while his flash gun goes into meltdown). If we are not allowed to have bib to police the flow and can only have automated systems instead then we are going to be stuck with only having offences that are easy to detect automatically.
Actually there is an offence such a driver could be prosecuted for. "Driving Without Due Consideration For Other Road Users" (words not exact).
Normally the sort of thing that it gets used for is the Combine Harvester driver who travels for an hour down a twisty A road and causes an hour long tailback by not pulling over or allowing traffic past.
BiBs may remember the incident? But there's a few incidents. In this case the onus would surely be on Trafpol to show that by driving in Lane 1 of the motorway at 40mph the driver was acting without due consideration...
To be honest I'd have thought pulling them over and a ticking off would have been more likely than a prosecution. After all - they weren't speeding or anything like that...
Personally I'd want to use the due consideration thing for lorries that insist on overtaking one another with a 0.01mph speed differential for twenty miles.
Normally the sort of thing that it gets used for is the Combine Harvester driver who travels for an hour down a twisty A road and causes an hour long tailback by not pulling over or allowing traffic past.
BiBs may remember the incident? But there's a few incidents. In this case the onus would surely be on Trafpol to show that by driving in Lane 1 of the motorway at 40mph the driver was acting without due consideration...
To be honest I'd have thought pulling them over and a ticking off would have been more likely than a prosecution. After all - they weren't speeding or anything like that...
Personally I'd want to use the due consideration thing for lorries that insist on overtaking one another with a 0.01mph speed differential for twenty miles.
towman said:
Personally I'd want to use the due consideration thing for lorries that insist on overtaking one another with a 0.01mph speed differential for twenty miles.
Dont blame us - blame the government that agreed to speed limiters.
tired old argument but I'm going to dust it off again... what's wrong with changing the limiter down a touch so you're doing 55.9 rather than 56.1 when you catch up with the other lorry? Does it make that much difference to the journey time compared to the difference made to all the car that then try to jam into lane 3? Or the lorry in front easing off for 20 seconds...
Of course our stupido government allowing lorries to travel at 70. But then we'd get the same happening at 69.9 and 70.1 wouldn't we?
This is only really a problem at a critical flow point - i.e. when traffic is dense but still free-flowing...
*dons flame retardant suit*
Iain
I see this on a daily basis as the m4 around here has some fairly large hills on it and combined with the goods from local steel works, quarries and some heavy plant facilities in the area means that some heavy equipment is doing less than 20 at the brow.
This is not really a problem, and in this case can't blame the drivers, as long as you can see it happening but when drivers of cars capable of doing much more than 70 sit petrified in the indide lane causing trucks to overtake them then IMO they should not be there. A good case for a separte motorway test?
This is not really a problem, and in this case can't blame the drivers, as long as you can see it happening but when drivers of cars capable of doing much more than 70 sit petrified in the indide lane causing trucks to overtake them then IMO they should not be there. A good case for a separte motorway test?
iaint said:
tired old argument but I'm going to dust it off again... what's wrong with changing the limiter down a touch so you're doing 55.9 rather than 56.1 when you catch up with the other lorry?
No doubt towman will provide a definitive answer, but I don't think you can. The limiter itself will be tamper-proof, with the threat of red hot pokers up the arse if you do try and tweak it, even to make it slower. You'd have to be using a separate cruise control, and it'd have to be extremely accurate, more so than car ones and on a vehicle that makes that kind of accuracy harder to achieve due to its greater mass and slower responses.
Compression waves of traffic are caused by drivers following too close to the car in front & or drivers braking at the first sign of brakelights as they have to. Its a knock on effect.
Leaving a bigger than normal gap allows you to absorb speed fluctuations, the bigger the fluctuation in speed the bigger the gap required.
However very few drivers are able to this, hence compression waves & stop start traffic accelerating into more stopped traffic. It amazes me that drivers dont see this effect & continue to do it hundreds of times.......
>> Edited by cptsideways on Tuesday 19th October 23:13
Leaving a bigger than normal gap allows you to absorb speed fluctuations, the bigger the fluctuation in speed the bigger the gap required.
However very few drivers are able to this, hence compression waves & stop start traffic accelerating into more stopped traffic. It amazes me that drivers dont see this effect & continue to do it hundreds of times.......
>> Edited by cptsideways on Tuesday 19th October 23:13
iaint said:
tired old argument but I'm going to dust it off again...
As pigeon said, we dont set the limit. There is no real defence to this, other than to say it is not illegal. I realise it can be frustrating for faster drivers if they get held up, but consider this; if a car is slowed by 20mph for ten minutes, the lost time can easily be made up. If we slowed every time we were potentially holding someone up, we can never make the time up due to the maximum speed.
Car drivers (of which I am one!) have the luxury of being able to exceed the speed limit if they choose. Can you imagine the chaos if cars had a 66mph limiter fitted? Would you really not attempt to overtake if your car was marginally faster than the one in front? Would you be happy to stare at the back of the vehicle in front for mile after mile after mile?
All we ask is a little understanding. Of all the road users, we are by far the most legislated and controlled. The job is not difficult any more, it`s bloody boring!
If you get stuck behind us, just chill out, be patient and whizz off into the distance when you get the chance.
Steve
Said it before, and will say it again I'm sure. Keep the speed limit for trucks at 60mph, and set the speed limiters at a maximum of 65mph.
Towman, do you remember the days before limiters? I used to sit on the motorway at 60-62mph. The trucks I drove could do 75mph at a push. It used to be out, overtake, then back in quick so's not to draw attention to myself. I seem to remember being more alert, because I had something to do, instead of just being a steering wheel attendant.
I am sure we didn't used to hold people up like we do now. Progress?
yeah right
Phil
Towman, do you remember the days before limiters? I used to sit on the motorway at 60-62mph. The trucks I drove could do 75mph at a push. It used to be out, overtake, then back in quick so's not to draw attention to myself. I seem to remember being more alert, because I had something to do, instead of just being a steering wheel attendant.
I am sure we didn't used to hold people up like we do now. Progress?
yeah right Phil
philthy said:
Towman, do you remember the days before limiters?
I most certainly do. Driving was much more enjoyable then. However, given that their were less motorways and by-passes etc, IMO car usage was much lower. Commuting distances were certainly much lower and hence there was much less traffic or arterial routes. Would I go back to the old days - no. Why? (Dangerously)Overworked, underpaid, trucks were crap etc etc etc.
Agree with you about the limiter thing though.
Steve
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