How fast do you drive on the motorway?

[strange6]

Yes, and create a whole load of worse problems in the meantime.

Like what? If you stay below 70mph, there will be no problem!

 

[ralphchadkirk]

No they're not. Police do not stop people for doing 79mph on the motorway as they allow 10% +3mph. Therefore according to you, police must be condoning reckless behaviour.

Ok, fair point. I thought it was 10% + 2mph anyway...

I live very close to the German border and regularly travel in my car which is capable of much more than 70mph (197mph if you're asking) on the Autobahns, quite happily past German police on many occasions. We could argue all day whether doing 197mph on a public highway is reckless, but doing 80-100mph if the conditions allow, in a car capable of it, is certainly not reckless, and the German law seems to agree with me.

In that case, people are expecting cars to be going fast, so the risk is less. Still, I don't think that driving a car flat out just because you can is a particularly safe way of doing things.

So, do me a favour Ralph, if ever you're in Germany doing 70mph, do please keep to lane 1 so important people can get by old chap.

Not everyone who travels at 197mph is important. In fact, if they are REALLY important rather than arrogant then they will be driving cautiously so they are less likely to have an accident

120mph on a bike or a car is reckless. I never said it wasn't.

Glad to hear it.

 

[The Barlow Boy]

Most motorways already are destricted, the speed limit for cars/bikes on a derestricted motorway is 70 mph.

If it's de-restricted why is the legal limit 70?
It's not de-restricted, every public road in the United Kingdom has a speed restriction on place. There is no such thing in the United Kingdom as a de-restricted public road.
--- old post above --- --- new post below ---

Interestingly, still no answer to my question.



To clarify - identical cars, identical conditions. No real variables, though in reality they wouldn't make too much difference to the figures.

If both cars are correctly spaced then the following one will stop in time.
--- old post above --- --- new post below ---

Assuming equal brake force at all speeds, as a first order approximation, 40mph.

More importantly, let's say both cars are next to each other (the faster one is overtaking) and both see an obstruction at the same time. If the car going 80mph stops just in time for an obstruction, let's say it stops 10cm from an overturned lorry across all lanes, the car that was going 120mph will smash into it at 90mph!

Now presumably motorways are designed (in terms of maximum curvature and lower speed limits where it gets curvy) so if you go 70mph and see an obstruction you can stop in time. What happens if you're going 120mph and see an obstruction?

You'll see an obstruction way ahead. I'm getting the idea here that many contributors to this are not regular motorway users. Motorways are much much safer because they don't have any of the major causes of "normal" accidents. There are no side roads, traffic lights, roundabouts, dithering learner drivers or slow moving agricultural machinery. The roads are straight with quite gentle curves (yes I know there are a couple of exceptions like south of Birmingham on the M5 and around Oxford on the M40 but even allowing for that there is a good uninterrupted view ahead). This coming across an obstruction business is a total red herring. The only time that they become unsafe is like on any road when fog or heavy rain reduces visibility and people still keep on going at too high a speed which brings me nicely back to the point I made earlier. It's not speed per se that's dangerous, it's inappropriate speed that does the damage plus the rapid decelleration upon impact.

 

[90019]

If both cars are correctly spaced then the following one will stop in time.

There is no following car, that's not the point of the question.

 

[The Barlow Boy]

I remember that episode. The idea of a derestricted Autobahn is that you travel at the maximum safe speed for the road ahead. The morons on TG decided to use it as a test track. Although the roads are derestricted, you often won't get going much faster than 70-80 because they can be quite busy roads. You don't drive "as fast as you possibly can" on an Autobahn; you should aim to drive as fast as it is safe to do so.

That's the entire point of why the "speed kills" myth is that. It's a myth.

The lorries issue is one of the reasons I would not increase the speed limit on a two lane motorway. You have to keep your wits about you on these motorways because they do pull out all of the time; if you go any faster you could easily be into the back of them if they pull out.

The lorry problem wouldn't be a problem if the government woke up out of the dark ages where they're still living in the days of a 28 tonner with hydraulically operated drum brake and realised that most every big artic with it's air operated ABS equipped disc brakes has a braking curve almost as good as a modern car plus the ability to cruise at 70.

 

[ralphchadkirk]

The lorry problem wouldn't be a problem if the government woke up out of the dark ages where they're still living in the days of a 28 tonner with hydraulically operated drum brake and realised that most every big artic with it's air operated ABS equipped disc brakes has a braking curve almost as good as a modern car plus the ability to cruise at 70.

Not sure how that has anything to do with the regular side-swiping that goes in.

 

[Nick W]

You'll see an obstruction way ahead.

Can you tell me with complete confidence that there's no obstruction between where the picture was taken and the end of the platform (approximately the braking distance at 120mph)?

 

[Soupstone]

Can you tell me with complete confidence that there's no obstruction between where the picture was taken and the end of the platform (approximately the braking distance at 120mph)?

You cant compare a picture to what you would see on a 3 lane lit motorway at 120MPH.

 

[ralphchadkirk]

You cant compare a picture to what you would see on a 3 lane lit motorway at 120MPH.

If anything, it's easier with the photo.

 

[The Barlow Boy]

Can you tell me with complete confidence that there's no obstruction between where the picture was taken and the end of the platform (approximately the braking distance at 120mph)?

..and how many cars are going along platforms 6/7 of King's Cross at motorway speeds?
holds head in hands at poster's seemingly inability to understand a simple premise.
--- old post above --- --- new post below ---

There is no following car, that's not the point of the question.

Yes it is, the poster asked a question quoting two identical cars, ome travelling at 120 the other at 80.
--- old post above --- --- new post below ---

Not sure how that has anything to do with the regular side-swiping that goes in.

Well if lorries could travel at normal motorway speeds they wouldn't have to keep pulling out to overtake each other at 5 mph.

 

[Soupstone]

The lorry problem wouldn't be a problem if the government woke up out of the dark ages where they're still living in the days of a 28 tonner with hydraulically operated drum brake and realised that most every big artic with it's air operated ABS equipped disc brakes has a braking curve almost as good as a modern car plus the ability to cruise at 70.

Ok, back to cars, but were braking distances not based on a Ford Anglia? With the motorway 70 limit set to it's top speed?

As you say, lorries (and all modes of transport) have improved since limits were set.

 

[ralphchadkirk]

Yes it is, the poster asked a question quoting two identical cars, ome travelling at 120 the other at 80.

holds head in hands at poster's seemingly inability to understand a simple premise.
It really is a simple question - even I understood it when it was first posted! Two cars, side-by-side, one at 80, one at 120, both apply their brakes at the same time, which will stop first?

 

[GearJammer]

Ok, back to cars, but were braking distances not based on a Ford Anglia? With the motorway 70 limit set to it's top speed?

As you say, lorries (and all modes of transport) have improved since limits were set.

Just a shame attitudes hav'nt!

 

[90019]

holds head in hands at poster's seemingly inability to understand a simple premise.
It really is a simple question - even I understood it when it was first posted! Two cars, side-by-side, one at 80, one at 120, both apply their brakes at the same time, which will stop first?

Not quite - the question is what speed the car that was originally at 120mph is doing when the car that was originally doing 80mph has come to a stop.

 

[ralphchadkirk]

Not quite - the question is what speed the car that was originally at 120mph is doing when the car that was originally doing 80mph has come to a stop.

True, but it has the same effect really. The 80 will have more chance of stopping before the obstruction.

 

[90019]

True, but it has the same effect really. The 80 will have more chance of stopping before the obstruction.

Approximately 400ft more chance.

 

[londonmidland]

7 people do 100mph on the motorway? Naughty naughty

 

[The Barlow Boy]

Ok, back to cars, but were braking distances not based on a Ford Anglia? With the motorway 70 limit set to it's top speed?

As you say, lorries (and all modes of transport) have improved since limits were set.

Yes, that's the whole point of this speed kills nonsense and 70 limit. When the 70 limit was set in December 1965 it was posted as a temporary measure. It was made permanent in 1967. At that time the average family vehcle was nearing it's maximum speed at 70, that plus cross-ply tyres and drum brakes as well as the fact that most had the build quality of a biscuit tin contributed to many acidents. As I posted earlier, the average mainstream family car is well capable of zipping along at 80+ and can stop a whole lot quicker and straighter with their radial tyres and ABS systems. My 2 litre diesel Golf is a fairly mundane family car yet it's performance in terms of braking, grip, stopping and maximum speed is vastly superior to many "sports" cars of the sixties. It'll outperform any Triumph Spitfire, MGB or Lotus-Cortina.
Most 38-42 ton lorries will outbrake all three of the above cars.

 

[Striker]

There is a clear conflict between the need to accommodate the demands of the lowest common denominator and the huge minority of skilled drivers who are quite capable of deciding for themselves what a safe speed is to drive at. With so many variables such as the weather, visibility, level of traffic, type of car, coming into play, no one speed limit is going to satisfy all scenarios. Hence 70mph. But by choosing to break this arbitrary speed limit, it doesn't automatically mean I am being reckless. Compare someone in an old car with poor brakes doing 69mph and me in a modern high performance vehicle with ceramic brakes doing 85mph. But according to some people on here I would be the one being reckless.

Personally, I prefer to use my own proven skill and judgement rather than some arbitrary figure which is around 4 decades old!

 

[The Barlow Boy]

True, but it has the same effect really. The 80 will have more chance of stopping before the obstruction.

Just remember that those braking distances were calculated many moons ago. Most every car will consistantly stop in a shorter - in many cases considerably shorter - distances. Have a look at the published braking distance for 40. Now go out in your car - you do have a car? - find a nice quiet dry level road and tread hard down on the middle pedal at a fixed point at 40. You'll be surprised at just how quickly you stop. Now measure the distance and compare.

 

[OxtedL]

I would like to point out that even on a lit motorway, it is not possible for a driver travelling at 120mph to see an obstruction and stop in time. It takes about 255m to react and come to a stop from 120mph (at least 8 seconds of what would have to be utter terror), and on most of the country's motorway you simply wouldn't be able to see that far to the level of sight required to spot obstructions. So by doing so you are taking a risk, even on any empty motorway. When you're unlikely to be concentrating fully anyway.

Food for thought there, perhaps.

 

[Soupstone]

I would like to point out that even on a lit motorway, it is not possible for a driver travelling at 120mph to see an obstruction and stop in time. It takes about 255m to react and come to a stop from 120mph (at least 8 seconds of what would have to be utter terror), and on most of the country's motorway you simply wouldn't be able to see that far to the level of sight required to spot obstructions. So by doing so you are taking a risk, even on any empty motorway. When you're unlikely to be concentrating fully anyway.

Food for thought there, perhaps.

Exit strategy. Braking is not always the best option.

 

[GearJammer]

It takes about 255m to react and come to a stop from 120mph (at least 8 seconds of what would have to be utter terror)

Where do you get those figures from?

 

[strange6]

I would like to point out that even on a lit motorway, it is not possible for a driver travelling at 120mph to see an obstruction and stop in time. It takes about 255m to react and come to a stop from 120mph (at least 8 seconds of what would have to be utter terror), and on most of the country's motorway you simply wouldn't be able to see that far to the level of sight required to spot obstructions. So by doing so you are taking a risk, even on any empty motorway. When you're unlikely to be concentrating fully anyway.

Food for thought there, perhaps.

With all these skilled drivers and modern cars knocking about, I'm surprised we have fatalities on our roads! Everybody thinks they're good at driving and that they know best but pride comes before a fall, and speed limits are there for a reason, especially on the UK's roads.

 

[OxtedL]

Indeed. I don't like saying it, and I know that everyone will ignore it, but you are far more at risk than you really would like to think. One crash is all it takes. Even highly experienced drivers can have accidents, and the higher the speed the more likely this is to be serious.

The figures from my post come from a mixture of sources, but I believe the highway code sets out 6.5ms-2 to be braking deceleration of a vehicle. Roughly. It won't be hugely far from the truth anyway, I fancy, but feel free to produce alternatives. Stopping distance is far further than anyone would like to believe. Of course braking is not the only option, but perhaps more controlled than skidding across the carriageway. Or smashing straight into the crash barriers.

Right, I'll just let everyone get on with continuing to try and justify excessive speed. 80mph by the speedo is more than enough for me most of the time. (I fancy I am well within tolerances, but even then I'm not exactly happy).

 

[ralphchadkirk]

The only person who has gone some way of convincing me that a rise to 80mph is acceptable is Striker.

 

[Zoe]

Due to climate change though, shouldn't we be thinking of reducing the limit to 60 mph? Actually if the limit was reduced to 56 mph there wouldn't be any need to overtake.

 

[Soupstone]

Due to climate change though, should't we be thinking of reducing the limit to 60 mph? Actually if the limit was reduced to 56 mph there wouldn't be any need to overtake.

Climate change? Another myth.

 

[ralphchadkirk]

Climate change? Another myth.

Really? Source?

 

[Soupstone]

Really? Source?

http://www.globalwarminghysteria.com/ten-myths-of-global-warming

http://www.dailymail.co.uk/sciencetech/article-440049/Greenhouse-effect-myth-say-scientists.html

http://www.timesonline.co.uk/tol/news/world/europe/article5430362.ece

http://www.marketoracle.co.uk/Article15687.html

Yes, the climate is changing, but not due to the reasons we've been force fed for years.

Just random googling, feel free to go to page 2.