Accidents per mile not tallying with safe limit ?
Discussion
I've had a look around the Almighty Net for figures and information about the average miles travelled per accident. That is, how many miles does the average driver drive until an accident is statistically probable.
What prompted this was my many, many journeys up and down the M5 between Taunton and Bristol over the past year at mostly rush hour times (6 to 8 evenings, 7 to 9 mornings). I have encountered in hundreds of journeys just 3 accidents that have caused the motorway to grind to a halt, and none of these as far as I know involved fatalities. I know I am not constantly on the M5, it is only a 50 mile stretch and that other accidents will have occurred but I would have thought the frequency of accidents per hour I've driven it would have been higher than I have experienced.
If the traffic on the part of the M5 I drive is representative of Britain's motorways, it strikes me that every day hundreds of thousands of drivers are averaging speeds above 80 and 90 mph with seemingly few accidents per mile or hour driven. Most cars I see are doing over 80mph. Many are doing over 90mph. A few are doing over 100mph. Therefore, very few are keeping to the safe speed limit of 70mph.
The huge number of journeys that happen across Britain each day and, from what I can tell, the small number of incidents occurring do not seem to tally with the enforcement of a 70mph limit on safety grounds.
I suspect that the limit is kept because to increase it, drivers would be doing 10mph over still. I.e. raise it 80 and people will mostly do 90mph. Or is it that the standard of driving is not sufficient to ensure most people can drive well at a higher speed?
It just seems nonsensical to strictly enforce a limit that reality suggests is both (a) far below the natural speed that drivers use on a wide and open road, and (b) is not particularly more safe than 80mph (for instance).
Any comments on this?
What prompted this was my many, many journeys up and down the M5 between Taunton and Bristol over the past year at mostly rush hour times (6 to 8 evenings, 7 to 9 mornings). I have encountered in hundreds of journeys just 3 accidents that have caused the motorway to grind to a halt, and none of these as far as I know involved fatalities. I know I am not constantly on the M5, it is only a 50 mile stretch and that other accidents will have occurred but I would have thought the frequency of accidents per hour I've driven it would have been higher than I have experienced.
If the traffic on the part of the M5 I drive is representative of Britain's motorways, it strikes me that every day hundreds of thousands of drivers are averaging speeds above 80 and 90 mph with seemingly few accidents per mile or hour driven. Most cars I see are doing over 80mph. Many are doing over 90mph. A few are doing over 100mph. Therefore, very few are keeping to the safe speed limit of 70mph.
The huge number of journeys that happen across Britain each day and, from what I can tell, the small number of incidents occurring do not seem to tally with the enforcement of a 70mph limit on safety grounds.
I suspect that the limit is kept because to increase it, drivers would be doing 10mph over still. I.e. raise it 80 and people will mostly do 90mph. Or is it that the standard of driving is not sufficient to ensure most people can drive well at a higher speed?
It just seems nonsensical to strictly enforce a limit that reality suggests is both (a) far below the natural speed that drivers use on a wide and open road, and (b) is not particularly more safe than 80mph (for instance).
Any comments on this?
deltafox said:
vonhosen said:
Don't forget the green lobby.
I suggest we do forget about the green lobby. Pointless nirks all of them using up valuable oxygen whilst breathing.
So run a car on ethanol or vegetable oil dependant on ignition! Hydrogen is also possible
The technology's there but we lack a government with the balls to stick 2 fingers at the vested interests and commission its development. Now back to the issue of the (crap) motorway speed limit and the lack of accidents despite the sheer numbers who exceed!
Edited by alphadog on Friday 15th September 18:47
V8S said:
I
I suspect that the limit is kept because to increase it, drivers would be doing 10mph over still. I.e. raise it 80 and people will mostly do 90mph.
I suspect that the limit is kept because to increase it, drivers would be doing 10mph over still. I.e. raise it 80 and people will mostly do 90mph.
I'm not convinced this would be the case. Sure some drivers would take the pee, but personaly I drive at a limit which I feel is comfortable and safe, wether that happens to be above or below the limit. If the limit was raised to 90mph tommorow, I wouldn't drive any faster, but I would certainly be driving more legaly most of the time.
MR2Mike said:
V8S said:
I
I suspect that the limit is kept because to increase it, drivers would be doing 10mph over still. I.e. raise it 80 and people will mostly do 90mph.
I suspect that the limit is kept because to increase it, drivers would be doing 10mph over still. I.e. raise it 80 and people will mostly do 90mph.
I'm not convinced this would be the case. Sure some drivers would take the pee, but personaly I drive at a limit which I feel is comfortable and safe, wether that happens to be above or below the limit. If the limit was raised to 90mph tommorow, I wouldn't drive any faster, but I would certainly be driving more legaly most of the time.
I think the majority of drivers in setting themselves a speed are influenced at least to some degree by what the limit is. Very few will drive with absolutely no regard to the limit or their margin over it.
If that is the case then a change in limit is going to mean a change in speed for a good number.
vonhosen said:
MR2Mike said:
V8S said:
I
I suspect that the limit is kept because to increase it, drivers would be doing 10mph over still. I.e. raise it 80 and people will mostly do 90mph.
I suspect that the limit is kept because to increase it, drivers would be doing 10mph over still. I.e. raise it 80 and people will mostly do 90mph.
I'm not convinced this would be the case. Sure some drivers would take the pee, but personaly I drive at a limit which I feel is comfortable and safe, wether that happens to be above or below the limit. If the limit was raised to 90mph tommorow, I wouldn't drive any faster, but I would certainly be driving more legaly most of the time.
I think the majority of drivers in setting themselves a speed are influenced at least to some degree by what the limit is. Very few will drive with absolutely no regard to the limit or their margin over it.
If that is the case then a change in limit is going to mean a change in speed for a good number.
Wouldn't affect me. I'd drive pretty much the same as I do now. I'm sure a well thought out campaign in papers and ad breaks stating that the new limit is an upper limit, rather than the speed to be aimed at would help. Educate the public properly.
The problem with the current limit is that it is so low, the lot of cars tend to drive at about 70, compounded on the bits of motorway where the scammers prowl. This causes bunching of traffic across the 3 lanes and causes an additional hazard due to the difficulty in maintaining a good volume of space all around the vehicle, not just from the car in front. Under these circumstances I find myself accomodating for other drivers much more than when traffic is flowing illegally!
I shudder to think what this 'Intelligent Speed Adaptation' governer will do to motorway driving if it comes into force. Like governed lorries, but worse!
vonhosen said:
Don't forget the green lobby.
Ja. the "greenier than thee " (Have you seen that new Tory logo
- I should have sent him doodles by my two year old.. she would have settled for a decent speed limit und reminded Dayveeee who pedals the fastest U-turns in the Westminster that he has to press the right pedal! 
) ) But don't get me started - Germans have saying in their press ..translates literally as: "Better a house in the greeny than a greeny in the house"
What with bugs in bins, fines for putting out an extra bag, putting out wrong bin on wrong day.. fortnightly collections .... they's do better to cop the fly tippers who seem now on increase
alphadog said:
vonhosen said:
MR2Mike said:
V8S said:
I
I suspect that the limit is kept because to increase it, drivers would be doing 10mph over still. I.e. raise it 80 and people will mostly do 90mph.
I suspect that the limit is kept because to increase it, drivers would be doing 10mph over still. I.e. raise it 80 and people will mostly do 90mph.
I'm not convinced this would be the case. Sure some drivers would take the pee, but personaly I drive at a limit which I feel is comfortable and safe, wether that happens to be above or below the limit. If the limit was raised to 90mph tommorow, I wouldn't drive any faster, but I would certainly be driving more legaly most of the time.
I think the majority of drivers in setting themselves a speed are influenced at least to some degree by what the limit is. Very few will drive with absolutely no regard to the limit or their margin over it.
If that is the case then a change in limit is going to mean a change in speed for a good number.
Wouldn't affect me. I'd drive pretty much the same as I do now. I'm sure a well thought out campaign in papers and ad breaks stating that the new limit is an upper limit, rather than the speed to be aimed at would help. Educate the public properly.
The problem with the current limit is that it is so low, the lot of cars tend to drive at about 70, compounded on the bits of motorway where the scammers prowl. This causes bunching of traffic across the 3 lanes and causes an additional hazard due to the difficulty in maintaining a good volume of space all around the vehicle, not just from the car in front. Under these circumstances I find myself accomodating for other drivers much more than when traffic is flowing illegally!
I shudder to think what this 'Intelligent Speed Adaptation' governer will do to motorway driving if it comes into force. Like governed lorries, but worse!
I'd imagine in the future you probbaly won't have to manage the gap either, the car will do practically everything for you. Driving as we know it will no longer exist, you'll merely be an extra passenger
vonhosen said:
I'd imagine in the future you probbaly won't have to manage the gap either, the car will do practically everything for you. Driving as we know it will no longer exist, you'll merely be an extra passenger
And when your cars operating system bluescreens? What then? If you seriously think that handing over crucial elements of the driving task to automated systems is a good idea,then you must be insane.
vonhosen said:
I think the majority of drivers in setting themselves a speed are influenced at least to some degree by what the limit is. Very few will drive with absolutely no regard to the limit or their margin over it.
If that is the case then a change in limit is going to mean a change in speed for a good number.
Interestingly (at least to me), what appear to be the speed habits on the Autobahn are not hugely different from what they are on British motorways, except for the quickest 5% (at a guess). If that is the case then a change in limit is going to mean a change in speed for a good number.
Half-ish of the Autobahn is restricted, and there is considerably more variation in the limit where restricted than there is in the UK (or in France, Belgium, etc.). That is to say, in Germany the speed limit does not appear to be arbitrary. The less arbitrary something is, the more likely people will take it seriously and respect it.
Speed cameras are much rarer in the restricted Autobahn sections than in UK, with fewer police or "mobile" speed traps than in France.
If anything, one sees more speed limit discipline in Germany. That is, on clear motorways, maybe 80-85% are doing within 10 kph of the speed limit, 5-10% are doing >10 kph below it, and 10-15% are doing >10 kph over it.
The same is generally true in the Britain.
The one difference that I have observed is that it is less common in Germany to see huge swathes of traffic doing what is plainly 10-20 mph over the posted limit, as can frequently be seen, for example, on the M4, M40, M3, etc. when conditions are benign. These pieces of motorway, if they were in Germany, would certainly be derestricted.
When you get to derestricted sections of Autobahn, what I would guess is 5% - no more than 10% - of drivers really put their foot down. Most everyone else seems to drive on derestricted sections at the same speed that they do on the common 130 kph sections, that is, near the 130 kph limit.
When left to their own devices, drivers seem to be capable of making individual decisions, influenced by what "feels like" the right speed.
By the way, although Germans in general are not the most solicitous and deferential of people, on Autobahns their lane discipline and respect for other road users seem to be better than the same are on British motorways.
I suspect most people would not up their speed much from what they do now. Or at least they would not do so regularly once the novely had worn off.
The reasons I would put forward are;
- that the difference in fuel consumption at 80+ a bit rather than 70+ a bit will become quite evident quite quickly and many will not feel the extra speed is worth the cost.
- that the typical car is geared to be somewhere near the top of its useful power peak when cruising in the 70 ish area and will be noticably noisier going that bit faster. While many people may not notice, some would and would drop back to the noise comfort zone they are used to.
I could be wrong, but I suspect that flemke's autobahn speed observations reflect what we would see here as well. Not that it will every come to pass.
The reasons I would put forward are;
- that the difference in fuel consumption at 80+ a bit rather than 70+ a bit will become quite evident quite quickly and many will not feel the extra speed is worth the cost.
- that the typical car is geared to be somewhere near the top of its useful power peak when cruising in the 70 ish area and will be noticably noisier going that bit faster. While many people may not notice, some would and would drop back to the noise comfort zone they are used to.
I could be wrong, but I suspect that flemke's autobahn speed observations reflect what we would see here as well. Not that it will every come to pass.
Stuff about autobahns aside, the thing I was getting at was the fact that most people seem to be driving 10 or 20 mph over the limit on motorways yet the number of accidents I myself have been inconvenienced by or heard about is quite low.
Are there statistics out there that either confirm or disprove that these large encroachments over the speed limit are not specifically increasing accidents by as large an amount as one would imagine?
Are there statistics out there that either confirm or disprove that these large encroachments over the speed limit are not specifically increasing accidents by as large an amount as one would imagine?
vonhosen said:
I think the majority of drivers in setting themselves a speed are influenced at least to some degree by what the limit is. Very few will drive with absolutely no regard to the limit or their margin over it.
If that is the case then a change in limit is going to mean a change in speed for a good number.
When Montana had no limits average speeds increased by <5mph.
There is a great deal of research which shows speed limits have little influence on drivers speed choice.
All that blanket speed limits do is oppress.
fluffnik said:
vonhosen said:
I think the majority of drivers in setting themselves a speed are influenced at least to some degree by what the limit is. Very few will drive with absolutely no regard to the limit or their margin over it.
If that is the case then a change in limit is going to mean a change in speed for a good number.
When Montana had no limits average speeds increased by <5mph.
There is a great deal of research which shows speed limits have little influence on drivers speed choice.
All that blanket speed limits do is oppress.
Agreed. The mountain roads in the Isle of Mann are another good example (where there are no limits). To the locals, who are used to the "no limits" roads, do not go "crazy". They find their comfort zone perfectly well without having a limit enforced.
james_j said:
fluffnik said:
vonhosen said:
I think the majority of drivers in setting themselves a speed are influenced at least to some degree by what the limit is. Very few will drive with absolutely no regard to the limit or their margin over it.
If that is the case then a change in limit is going to mean a change in speed for a good number.
When Montana had no limits average speeds increased by <5mph.
There is a great deal of research which shows speed limits have little influence on drivers speed choice.
All that blanket speed limits do is oppress.
Agreed. The mountain roads in the Isle of Mann are another good example (where there are no limits). To the locals, who are used to the "no limits" roads, do not go "crazy". They find their comfort zone perfectly well without having a limit enforced.
Isle of Man recently looked at having speed limits introduced because of concerns over the proportion of fatalities on their derestricted roads.
www.iomguide.com/news/general-news.php?story=100822
alphadog said:
So run a car on ethanol or vegetable oil dependant on ignition! Hydrogen is also possible
Interesting, if you do this, because of the fact that motor taxes are purely levied to prevent global warming, the Govt will reward you for your unselfish act of protecting the environment, by prosecuting you for tax evasion.
Vonhosen said:
Isle of Man recently looked at having speed limits introduced because of concerns over the proportion of fatalities on their derestricted roads.
Incorrect. The problem with the IOM was that they imported an enforcement obsessed zealot from the mainland as police comissioner who simply could not accept the derestricted status quo.
Richard C said:
Vonhosen said:
Isle of Man recently looked at having speed limits introduced because of concerns over the proportion of fatalities on their derestricted roads.
Incorrect. The problem with the IOM was that they imported an enforcement obsessed zealot from the mainland as police comissioner who simply could not accept the derestricted status quo.
So they didn't look at introducing speed limits because of deaths on the derestricted roads as per the link I gave then ?
The statement from the minister for transport that I gave a link to is a complete fabrication is it ?
The likelhood of a accident is proportional to the differences in speed of vehicles on a section of road, the seriousness of an accident is proportinal to the absolute speed of the vehicles involved. So with all cars going 80-90mph the likelihood of an accident is the same as if they were going 50-60, but if an accident were to occur the cosequences would be much worse. Physics; energy being proportional to the square of the velocity.
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