Motorway Speed Limits - Out of date yet?

[the B]

To see the speed limit as solely being about stopping distance illustrates a serious problem with road safety - drivers seeing things only from their own point of view. It's also about how hard other vehicles hit you - let's assume for the sake of getting the point across that it's always the other driver's fault, and accept there are nutters out there. How hard they hit you rises as the square of the closing speed (twice as hard at 100 as at 70).

As a thought experiment, I'll support no speed limit at night if drivers accept my tradeoff.

It's this: you agree to be woken by the traffic police at random hours of the night - on a lottery basis - and taken off to scoop up some boy racer and his passengers and the people he's killed in other cars. With a teaspoon.

Road safety can actually be vastly improved by people deciding to drive around in F1 style safety gear... flame proof suits, crash helmets, HANS devices, heavily reinforced car bodywork, tethered tyres etc.

That way people can drive around at 200 mph and be safe

 

[kained&able]

f1 could be made safer by putting the car clearence up a bit and fitting full cockpits to the cars rather then have people heads sticking out into air.


dave

 

[laptop]

Road safety can actually be vastly improved by people deciding to drive around in F1 style safety gear... flame proof suits, crash helmets, HANS devices, heavily reinforced car bodywork, tethered tyres etc.

But it would be improved a lot more by making the driver sit on the outside with an evil spike in the middle of the steering wheel.

That way people can drive around at 200 mph and be safe

But not the people they ran into...

 

[the B]

But it would be improved a lot more by making the driver sit on the outside with an evil spike in the middle of the steering wheel.

That too It's one of my favourite ones that!

 

[the B]

f1 could be made safer by putting the car clearence up a bit and fitting full cockpits to the cars rather then have people heads sticking out into air.


dave

Actually, the clearence level isn't such a huge deal considering that the tracks are made with it in mind. Full cockpit, can't fault that but then, how it would affect visiblity has to be thought out really.

 

[the B]

But not the people they ran into...

Provided the people are in cars... pedestrians are pretty much minced, yes.

 

[kained&able]

umm but we are talking on the motorway raising limits. not any peds on there or cyclists.


dave

 

[KeyboardJockey]

45? Are you a large vehicle?

A very old and underpowered for a 1.5 imperial ton Series III Land Rover 2.2litre Diesel. 62BHP when new and with wear and tear about 55 BHP now.

 

[KeyboardJockey]

On a lot of cars, tyres are actually as or far more important than any other component...

Agreed. Because of the type of vehicle I buy quality remoulds and maintain them properly. To get good fuel consumption I have tyres rated for 60% on road and 40% off road. I lose some off road performance but for bog standard greenlaning or dragging stuff around the allotment site it doesn't make much difference. I'm currently looking at 205R16 Insa Turbo Remoulds from John Craddock Ltd which are totally rated for road use and keep the 60/40's for when I go off road.

At the moment I get about 28mpg from my motor and I reckon I can squeeze a few more MPG out of it with the totally road tyres because of the lesser rolling resistance.

 

[Donna Ferentes]

umm but we are talking on the motorway raising limits. not any peds on there or cyclists.

No, but there are other people in cars. Who are entitled to be protected from the bloody lunatics.

 

[Poi E]

It's this: you agree to be woken by the traffic police at random hours of the night - on a lottery basis - and taken off to scoop up some boy racer and his passengers and the people he's killed in other cars. With a teaspoon.

I'll agree to that if all drinkers are randomly plucked from the pub and asked to care for someone in the last stages of alcoholic cirrhosis of the liver.

 

[axomoxia]

Firstly, rasing the speed limit dosn't mean you have to drive at the speed limit.... if you have an older car, just slow down and keep plenty of difference between you and the vehicle in front. (Thats how you spot un-marked police vehicles - doing 60, in the inside lane, keeping a proper distance from the vehicle in front. Stands out a bloody mile)

As to speeding, the safe speed for a vehicle is dependant on a huge number of factors, that change as a journey progresseses. Junctions, other road users, road surface, street furniture. A safe speed may be less than the posted limit, it may be more. I'd far rather people slowed down for hazards and sped up again in thier abscense, than blindly obeyed a speedlimit sign. Do you really want people to do 30 in a narrow double parked residential sidestreet?

 

[KeyboardJockey]

Firstly, rasing the speed limit dosn't mean you have to drive at the speed limit.... ........... Do you really want people to do 30 in a narrow double parked residential sidestreet?

Spot on. It's a limit not an instruction. My small side turning where I live has a 30 limit but because it is shared with pedestrians and cyclists and children playing I never ever do more than 12-15 on it if that.

 

[kained&able]

but people aren't being protected from bloody lunitics currently. if they were then there wouldn't be any bloody lunitcs on the road in the first place.

surely the issue is will 10mph extara create more lunitics or not.


dave

 

[aylee]

The speed limits were set some time ago at 70mph when car technology was a lot different to the cars we drive today. The stopping distances have equally been the same for some length of time.

I think speed should be kept low in built up areas particularly schools but motorway driving at 80-100mph outside of peak hours is acceptable. Perhaps a variable speed limit based on driving conditions is an option.

Am I being stupid in thinking that perhaps the income generated by speeding motorway drivers is a factor keeping the limit's down?

I doubt that your last point has anything to do with it. I agree that the existing laws are out-of-date and will admit to driving faster than the speed limit on motorways when conditions allow. However, I'd be wary about raising speed limits beyond about 80mph, in case people start to work on the basis of 120mph rather than 90-100mph being the 'norm' in the outside lane.

I think that speed limits of 70mph are a major cause of motorway bunching due to fuckwits driving at just under that speed in the middle lane.

 

[Jangla]

If you give me a few days, I can get some figures on skid distances from my old man (he's an ex-Met traffic cop, who's done a shed load of accident investigations). Apparently, given the same vehicle and conditions, the skid distance increases dramatically with speed.

Of course.

The point I was making was that the stopping distances on the back of the highway code are no based on skidding distance. They're based on an Austin Healey in dry and clear conditions and stopping without skidding.

 

[Griff]

I hardly see any lunatics on motorways, just people who don't have lane discipline and people who sometimes drive too close. I don't think having an extra 10 mph will make any difference. Just look at the people who drive at 65 in the middle or outer lanes. Plus the people who drive at 80 mph anyway.

As I said earlier, I try to avoid motorways if at all possible.

 

[Jangla]

To see the speed limit as solely being about stopping distance illustrates a serious problem with road safety - drivers seeing things only from their own point of view. It's also about how hard other vehicles hit you - let's assume for the sake of getting the point across that it's always the other driver's fault, and accept there are nutters out there. How hard they hit you rises as the square of the closing speed (twice as hard at 100 as at 70).

To be fair, if someone hit you with a resultant speed of 70mph (or you hit an immoveable, non-deforming barrier), you'd be dead no matter what you were driving.

The point is that on a motorway, the relative speed of each car is only a few miles per hour more or less than the next guy.

 

[Donna Ferentes]

The point is that on a motorway, the relative speed of each car is only a few miles per hour more or less than the next guy.

Yes, but if it's "less", that could save a person's life.

 

[Jangla]

Yes, but if it's "less", that could save a person's life.

And if it was 10mph almost no-one woud die. Not practical though, is it? A balance must be struck between the level of technology available, the quality of the road and the requirement to keep traffic moving.

Besides, increasing the speed limit for all won't change the relative speed of each vehicle.

 

[Donna Ferentes]

Increasing the speed limit for all won't change the relative speed of each vehicle.

Well, it will, because increasing the speed limit doesn't mean that somebody who was stationary now goes at 10mph. Come to that, it doesn't mean that somebody who was going at 40 now goes at 50. Actually, it's a completely absurd point.

 

[the B]

Crash helmets and HANS devices for all!
Roll cages in all vehicles!
Tyres must be tethered!
5 point safety harnesses with 150% wider belts!
All vehicle passengers to wear Nomex!
Monocoque structures out of honeycombed reinforced carbon fibre!

 

[KeyboardJockey]

Crash helmets and HANS devices for all!
Roll cages in all vehicles!
Tyres must be tethered!
5 point safety harnesses with 150% wider belts!
All vehicle passengers to wear Nomex!
Monocoque structures out of honeycombed reinforced carbon fibre!

Or even make all vehicles like this one...

Made in Sollihul from girders and Spitfire plane alloy.

 

[Jangla]

Well, it will, because increasing the speed limit doesn't mean that somebody who was stationary now goes at 10mph. Come to that, it doesn't mean that somebody who was going at 40 now goes at 50. Actually, it's a completely absurd point.

ok, the relative speed won't change for drivers driving at the speed limit.
The point I was trying to highlight is that despite the speed limit being 70mph, relatively few people experience a crash where all that speed is transferred directly to them and if they do, they don't survive; therefore increasing the spped limit to 100mph, for example, wouldn't increase the number of deaths by a squred proportional factor as the liklihood of death is directly linked to the relative speed of ..... you know what, you're not going to change your mind and I've made and clarified my point so this is all wasted bandwidth

 

[Giles]

There are quite a few of us who still drive cars with Drum Brakes. To lessen the stopping distance and not take this into account would be dangerous.

Surely the "official" guideline figures should be based on the "average" current vehicle?

After all, when they based it on that Austin-Healey, they did so because it was a current model at that time, not one 30 years out-of-date.

I did have a car with drums all round but I got discs fitted on the front after a couple of scary situations. (1961 Triumph Herald FYI).

Giles..

 

[Giles]

they have these things called light above the motorways makes seeing really really easy.


any car wiothout a catalitic convertor should indeed be phased out and then banned.


dave

What has a catalytic converter got to do with road safety and speed limits?

I have an old car and I am not going to stop driving it, and it does not have a catalytic converter.

Giles..

 

[Giles]

Easy - ban cars with all round drum brakes.

In fact, any car that's pre-cat and pre-ABS should be off the road IMO - there should be a separate 'Classic' classification with attendent additional costs to drive but the problem with road and motorway safety is precisely because it has to take account of the most primitive cars on the road.

This is clearly nonense. Most accidents are not in any way caused by defective or even less-than-100% brakes. They are caused by people driving badly, not looking where they are going, going to fast for the circumstances, too close to car in front, etc.

Most times I drive past an accident, is it a classic car? Is it fuck! Most older cars (like my Herald) wouldn't benefit from an increased speed limit on motorways cos they don't go that fast.

And if you banned non-ABS cars you would take away many brand-new vehicles.

Giles..

 

[kained&able]

nowt to do with car safty. seperate paragraphs. I think that non cat converted cars should be banned beacuse they fuck up the environmeant even more quickly then other cars.


dave

 

[Griff]

And if you banned non-ABS cars you would take away many brand-new vehicles.

Giles..

TVRs

But they do have one of the highest percentages of deaths on the road not involving other vehicles.

 

[MikeMcc]

Of course.

The point I was making was that the stopping distances on the back of the highway code are no based on skidding distance. They're based on an Austin Healey in dry and clear conditions and stopping without skidding.

Granted, but the selection of a speed limit should be based on the possibility of losing control, how far you can travel when out of control and the likelyhood of damage to others in the process. That's why I'm not so worried about speeding at 85 on a motorway compared to doing 35 in a 30 limit

Edited because I still need to proof read first