Why the 40mph limit?
Discussion
I see more and more lorries with the "Limited to 40 mph on single carriageways" sticker on the back.
I understand the 56mph limit I guess, but in my experience the 40 mph limit just creates a mile long tailback full of impatient angry car drivers.
By the time you have the length of the lorry and the mandatory 2 - 3 small hatchbacks bunched up behind it with no intention of overtaking, it effectively creates a 40 mph moving road block on a NSL road?
Am I missing something?
I understand the 56mph limit I guess, but in my experience the 40 mph limit just creates a mile long tailback full of impatient angry car drivers.
By the time you have the length of the lorry and the mandatory 2 - 3 small hatchbacks bunched up behind it with no intention of overtaking, it effectively creates a 40 mph moving road block on a NSL road?
Am I missing something?
The maximum speed for vehicles over 7.5T gross weight on NSL single carriageways is 40mph. I guess it's for the safety of other people, namely the ones who hoon around blind corners at 100mph. Faced with the choice of crashing head on into a lorry doing 40mph and one doing 55mph I know which I'd prefer.
I remember some quite high profile accidents with resultant nasty collisions back in the 80`s where lorries had been bombing along on typical A roads. The result was the typical nanny state blanket over reaction with the imposition of speed limiters and the 40mph speed limit on 60mph limit roads.
Things were a mess and lorries were travelling too fast, but 40mph is just as crazy and I personally find it very hard to concentrate at this speed, which is not good. Personally 50mph is far more sensible. It is fast enough to make adequate progress and therefore make it tolerable to sit in a queue on busy roads, yet still slow enough to give drivers time to react to changing road conditions. By the way, you`ll never stop all accidents, not at least until cars/lorries are fully automatic but even then, what about wild animals suddenly running out, or loss of gps location etc etc. There is along way to go on this one yet.
Things were a mess and lorries were travelling too fast, but 40mph is just as crazy and I personally find it very hard to concentrate at this speed, which is not good. Personally 50mph is far more sensible. It is fast enough to make adequate progress and therefore make it tolerable to sit in a queue on busy roads, yet still slow enough to give drivers time to react to changing road conditions. By the way, you`ll never stop all accidents, not at least until cars/lorries are fully automatic but even then, what about wild animals suddenly running out, or loss of gps location etc etc. There is along way to go on this one yet.
LeoSayer said:
It's the law and I guess it might stop following from drivers from getting annoyed, or at least be a bit more understanding.
I think the OP is asking "Why the Limit?" and not "Why the Stickers?"I think the answer to "Why the Limit" would be safety. On a single carriageway road a big old lorry takes up quite a lot of space. They can't see as far as on multi carriageway roads due to hedges and the like, and the vehicles can't stop as quickly as cars (in general). The single carriageway roads tend also to be more winding etc than multi carriageway roads. So there's a load of reasons, basically, why it would be daft for a big lorry to be doing the same speed as a car. Often there are occasions where a lorry doing 60 would be no problem at all. But our speed limits cater for the lowest common denominator, and err on the side of caution. Hence the lower limits for trucks.
kambites said:
I'm not sure I'd really want artics hammering down twisty B-roads at 60mph. 
I did follow one on a pretty windy oxfordshire road once, driven on mostly its 56mph limiter - the lines it took, smoothness of the driver and the placement on the road where superb. Shame it was bloody dangerous. A pleasure to watch though.The 40 limit for what was HGVs but now LGVs over 7.5 tonnes was made years ago when air brakes were not even thought of
they are now well outdated for most of the trunk roads we have and 50 would be a better realistic safe limit
A change in the law to allow roads to be 50 and to sign them with a lorry that has a 50 in it might work and then the same sign with a red line to indicate where it ends - perhaps?
they are now well outdated for most of the trunk roads we have and 50 would be a better realistic safe limit
A change in the law to allow roads to be 50 and to sign them with a lorry that has a 50 in it might work and then the same sign with a red line to indicate where it ends - perhaps?
As above some A roads you just can't get upto 40 mph for long periods of time when fully loaded, road from Newbury to Basingstoke Springs to mind. Others you could easily welly down them on the limiter all day long.
I agree 50mph would be better,but obviously not applicable to all A roads.
I agree 50mph would be better,but obviously not applicable to all A roads.
I think a 50 limit would make a lot of the roads around here safer. I use the A1 North of Newcastle up to Edinburgh and pretty much the only time I drop to 40 is for the cameras or letting a faster vehicle pass. The rest of the time it's 50-56mph. There's some suicidal overtakes go on when traveling at 40.
Bit of a double-edged sword really.
On the one hand you risk frustrating the impatient muppet in a capable vehicle who is incapable of waiting for a safe overtake.
On the other hand, it is much easier when driving an underpowered vehicle (van, tepid little hatchback etc) to get safely past a wagon doing 40, than one doing 50.
Whether on the bike or in the van I always prefer to come up behind a wagon sticking to 40 - purely for ease of passing.
On the one hand you risk frustrating the impatient muppet in a capable vehicle who is incapable of waiting for a safe overtake.
On the other hand, it is much easier when driving an underpowered vehicle (van, tepid little hatchback etc) to get safely past a wagon doing 40, than one doing 50.
Whether on the bike or in the van I always prefer to come up behind a wagon sticking to 40 - purely for ease of passing.
The Curn said:
I see more and more lorries with the "Limited to 40 mph on single carriageways" sticker on the back.
They put the stickers on there because the majority of car drivers do not know that the speed limit is 40mph for a truck on a single carriageway and then phone up head office complaining that they're stuck behind a lorry doing 20mph under the limit and holding traffic up 
The limit is stupid, I am of the opinion that the limits shouldn't be weight related and should just conform to the towing regulations. If someone is hammering it about at a speed they are losing control at or cause an accident then it should just be dangerous driving, there are too many variable types of single carriageway in this country to just have a blanket 40mph limit.
mp3manager said:
How many in this thread have actually driven a truck?
As a truck-driver, I pull a 16ft double decker, which is inherently top-heavy, and I can assure you that 40mph is plenty fast enough.
I drive a truck, i pull containers, a 40ft high cube loaded up with bales of waste paper grossing out at nearly 44tonnes can be top heavy, i think the speed limit should be raised to 50mph, i hear what you say about top heavy loads but just because the limit can be raised to 50mph does'nt mean you have to drive at 50mph, we should be allowed to drive these trucks at whatever we consider to be a safe speed, ive driven on A roads at over 40mph with a top heavy load.... but only where it was safe to do so.As a truck-driver, I pull a 16ft double decker, which is inherently top-heavy, and I can assure you that 40mph is plenty fast enough.
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