Driving at the speed limit
Discussion
In the last few days I've been trying to stick closer to speed limits. I don't mean the 20s, 30s, 40s in towns -- I always stick to these -- but the NSLs. I thought it might be interesting to post the results of this experiment.
As background, I have been driving for over 20 years, have attended a number of defensive driving courses, had skid pan training, etc, etc. I drive around 40k miles a year. I've worked in Germany a lot over the last 10 years and I am capable of the necessary disciplines in unrestricted conditions. And apart from being run into the back of on the M40 one Friday afternoon by a lady in a hurry (she was the only one not braking at the time!), who immediately admitted responsibility, I've never been involved in an accident. I love driving, and always aim to drive carefully, within my limits, appropriately for the conditions, etc.
Results:
1) I arrive later! May sound obvious, but the Government wants us to believe that somehow speed doesn't have an effect on our journey times
2) Much less stress searching out hidden cameras, talivans, unmarked cars, etc
3) Much more distracted constantly watching the speedo
4) Much easier to stop concentrating
5) Temptation to ignore the urban speed limits, to make up for lost time
6) Much more stress driving at a speed which is pretty much the same as every other car's. On motorways, the outside lane is effectively out of bounds when driving at 70 so you're stuck in the inner 2. Doing it properly, you have to repeatedly and constantly look for a gap in lane 2, overtake, move back in. This is hard work. Result: a strong desire to sit in lane 2 at 70.
My feelings on this:
1) I like the idea of lowering my stress levels while driving
2) It's very hard to drive properly at 70 limit
3) Lower levels of concentration are clearly not a safety benefit!
4) The result of a low limit that all cars are capable of, is that the simplest strategy is middle lane-hogging at 70. This is the most effective way to reduce stress.
I therefore feel that the current huge level of middle lane-hogging is caused by more people travelling at the speed limit, which in turn is caused by the increase in surveillance. From my experience, I would say that these people are also driving with low levels of concentration. In addition, I'm sure we've all seen people who ignore lower speed limits ("45 in 60, 45 in 30"), which may be a result either of reduced concentration or a need to make up time.
Together, it seems to me that these factors could result in an increase in accidents rather than a reduction. Perhaps this is what we're seeing with the recent accident figures in heavily Gatso'd counties?
I think there should be much more research on the real effects of low speed limits on good roads, rather than just assume every road will automatically be safer with lower limits. While I hate people driving fast through my village when I'm walking my 4 year old to school, I really can't see a problem with 100+ on a dry empty motorway -- and nor can the Germans!
I hope this is of interest.
As background, I have been driving for over 20 years, have attended a number of defensive driving courses, had skid pan training, etc, etc. I drive around 40k miles a year. I've worked in Germany a lot over the last 10 years and I am capable of the necessary disciplines in unrestricted conditions. And apart from being run into the back of on the M40 one Friday afternoon by a lady in a hurry (she was the only one not braking at the time!), who immediately admitted responsibility, I've never been involved in an accident. I love driving, and always aim to drive carefully, within my limits, appropriately for the conditions, etc.
Results:
1) I arrive later! May sound obvious, but the Government wants us to believe that somehow speed doesn't have an effect on our journey times
2) Much less stress searching out hidden cameras, talivans, unmarked cars, etc
3) Much more distracted constantly watching the speedo
4) Much easier to stop concentrating
5) Temptation to ignore the urban speed limits, to make up for lost time
6) Much more stress driving at a speed which is pretty much the same as every other car's. On motorways, the outside lane is effectively out of bounds when driving at 70 so you're stuck in the inner 2. Doing it properly, you have to repeatedly and constantly look for a gap in lane 2, overtake, move back in. This is hard work. Result: a strong desire to sit in lane 2 at 70.
My feelings on this:
1) I like the idea of lowering my stress levels while driving
2) It's very hard to drive properly at 70 limit
3) Lower levels of concentration are clearly not a safety benefit!
4) The result of a low limit that all cars are capable of, is that the simplest strategy is middle lane-hogging at 70. This is the most effective way to reduce stress.
I therefore feel that the current huge level of middle lane-hogging is caused by more people travelling at the speed limit, which in turn is caused by the increase in surveillance. From my experience, I would say that these people are also driving with low levels of concentration. In addition, I'm sure we've all seen people who ignore lower speed limits ("45 in 60, 45 in 30"), which may be a result either of reduced concentration or a need to make up time.
Together, it seems to me that these factors could result in an increase in accidents rather than a reduction. Perhaps this is what we're seeing with the recent accident figures in heavily Gatso'd counties?
I think there should be much more research on the real effects of low speed limits on good roads, rather than just assume every road will automatically be safer with lower limits. While I hate people driving fast through my village when I'm walking my 4 year old to school, I really can't see a problem with 100+ on a dry empty motorway -- and nor can the Germans!
I hope this is of interest.
Interesting, informative, personal viewpoint backed up by (admittedly statistically insignificant) research.
Won't go anywhere though unfortunately. I agree with everything that you have said - particularly the middle lane stuff - having watched coutless drivers cut across in front of the hogs to try and get a point across.
Unfortunately you haven't included a catch slogan with no bearing on the situation (speed kills). It's all about PR these days
.
Won't go anywhere though unfortunately. I agree with everything that you have said - particularly the middle lane stuff - having watched coutless drivers cut across in front of the hogs to try and get a point across.
Unfortunately you haven't included a catch slogan with no bearing on the situation (speed kills). It's all about PR these days
.
schueymcfee said: ...or Numpties Kill
Kill a numpty, not your speed!
Classic!
Don't do it though....I'm not sure being a numpty deserves the death sentence. Years of imprisonment..YES! Death...no.
Oh. I tried the same experiment once. Why? Because I was taking an Advanced Driving course and I wanted to ensure that I knew exactly how fast 70mph was and how to drive defensively at that speed.
I cannot agree about a decrease in concentration or an increase in stress on the Motorway.
I DID get sick of numpties tailgating me (I drive a Porsche) it seemed to take them a MINUTE or TWO to realise I wasn't going to speed up and then they would usually pull out with a lurch and no indication to pass.
I can confirm it took longer to get everywhere. By up to 20-25% on longer journeys.
As it happens I just drove from Birmingham to London at about 75mph, I'm not surely I entirely agree with your comments.
Yes - it can be tempting to stay in the middle lane if the occasional inconsiderate driver blocks you in with the lane next to him free to use. But if you watch your mirrors you can generally get out in time, most of the cars I came across were only doing 80/85, there was only the occasional charger at 100+.
And the argument about speeding through urban areas is surely irrelevant - why would you (in real life) drive at the speed limit on a motorway then try and make up time when you get to your destination? If you are really are in a hurry you would have gone faster in the first place. Anyway being late is not an excuse for driving too fast in town, just leave earlier.
I find driving at 70-80 on UK motorways relatively relaxing (other than occasionally getting blocked in like I say - ever tried towing a trailer?). Conversely I find trying to stay at over 100mph quite stressful.
Oh - I've been driving about 20 years too, currently 25-30K a year, lots of rallying/motorsport experience but no formal advanced road training.
Yes - it can be tempting to stay in the middle lane if the occasional inconsiderate driver blocks you in with the lane next to him free to use. But if you watch your mirrors you can generally get out in time, most of the cars I came across were only doing 80/85, there was only the occasional charger at 100+.
And the argument about speeding through urban areas is surely irrelevant - why would you (in real life) drive at the speed limit on a motorway then try and make up time when you get to your destination? If you are really are in a hurry you would have gone faster in the first place. Anyway being late is not an excuse for driving too fast in town, just leave earlier.
I find driving at 70-80 on UK motorways relatively relaxing (other than occasionally getting blocked in like I say - ever tried towing a trailer?). Conversely I find trying to stay at over 100mph quite stressful.
Oh - I've been driving about 20 years too, currently 25-30K a year, lots of rallying/motorsport experience but no formal advanced road training.
Good write up of your experiment mate!
I might publish the source code to a road simulator I have written in VB - it clearly shows that lane changing is inefficient, and that lane hogging is indeed the fastest, less stressful method of A->B travel... and strangely enough, it is our "keep left" code that makes the right hand lane get jammed up.
Incidentally, and scarily, high performance vehicles actually seem to clog the system up as they have better acceleration & braking. But that's only my simulator
.
C
I might publish the source code to a road simulator I have written in VB - it clearly shows that lane changing is inefficient, and that lane hogging is indeed the fastest, less stressful method of A->B travel... and strangely enough, it is our "keep left" code that makes the right hand lane get jammed up.
Incidentally, and scarily, high performance vehicles actually seem to clog the system up as they have better acceleration & braking. But that's only my simulator
. C
The effect of speeding on journey time largely depends on the traffic conditions.
I have the joy of driving on the M25 Northwest quadrant between the M4 and the A1M on most days.
At 3am speeding really cuts journey times. However, at 9am, you'd be lucky to actually get to 70mph on most days.
Thing is...if you're doing 90, and then you get stuck behind some peasant doing 60 in the outside lane, the guy who was doing 70 all along will catch in no time.
I have the joy of driving on the M25 Northwest quadrant between the M4 and the A1M on most days.
At 3am speeding really cuts journey times. However, at 9am, you'd be lucky to actually get to 70mph on most days.
Thing is...if you're doing 90, and then you get stuck behind some peasant doing 60 in the outside lane, the guy who was doing 70 all along will catch in no time.
Thanks, This does make some interesting reading although I personally feel that if everyone stuck to the limits, rather than speeding, that most of the problems on the motorways would go away. Bad lane discipline and lane hogging causes major problems - there's plenty of tarmac around so why don't people just get in the pigging inside lane and let others past. NOT TO MENTION THOSE IDIOTS SITTING FAR TOO CLOSE TO THE REAR END OF THE CAR IN FRONT - NO EXCUSES YOUR GOING TO CRASH! 
Out of interest the focus on your speedometer is nothing new. I to have passed the Advanced Driving and found it incredibly difficult to maintain the speed limits exactly. I found the only way to maintain a good balance of concentration without exceeding the speed limit was to buy a car with cruise control. No fun I know but that's what this country is coming too.
Out of interest the focus on your speedometer is nothing new. I to have passed the Advanced Driving and found it incredibly difficult to maintain the speed limits exactly. I found the only way to maintain a good balance of concentration without exceeding the speed limit was to buy a car with cruise control. No fun I know but that's what this country is coming too.
Lucozade, you're right up to a point. My sim shows that if you set the cruising speed to the same for all vehicles, you get maximum flow - and zero lane changing as there is no advantage to change lane. When I tweak the speed of one car objects on the sim, it has a major effect on all the other cars. Slow it down too much, and lane hogging takes place as people "queue" to get past. Too fast, and it "surges" or yo-yo's which is also disruptive.
Interestingly (sad I know) but if I adjust the braking of just *one* car to be double that of the others, you guessed it - pile up. Likewise, too much acceleration, and the same thing.
You'd be amazed at the calculations required to simulate a 3 lane road... and then we all wonder why the M25 gets clogged up?
C
Interestingly (sad I know) but if I adjust the braking of just *one* car to be double that of the others, you guessed it - pile up. Likewise, too much acceleration, and the same thing.
You'd be amazed at the calculations required to simulate a 3 lane road... and then we all wonder why the M25 gets clogged up?
C
Good points made by the two Peters (Ward and spn) though, spn, I suspect that you've got cruise control on your luxo-barge which removes the speedo-watching stress.
Lack of concentration there's no excuse for of course, though I also found this to be the case when I've tried to stick to the 70mph speed limit on a motorway. I took some mental re-training, is all.
Lack of concentration there's no excuse for of course, though I also found this to be the case when I've tried to stick to the 70mph speed limit on a motorway. I took some mental re-training, is all.
hertsbiker said: Lucozade, you're right up to a point. My sim shows that if you set the cruising speed to the same for all vehicles, you get maximum flow - and zero lane changing as there is no advantage to change lane. When I tweak the speed of one car objects on the sim, it has a major effect on all the other cars. Slow it down too much, and lane hogging takes place as people "queue" to get past. Too fast, and it "surges" or yo-yo's which is also disruptive.
Interestingly (sad I know) but if I adjust the braking of just *one* car to be double that of the others, you guessed it - pile up. Likewise, too much acceleration, and the same thing.
You'd be amazed at the calculations required to simulate a 3 lane road... and then we all wonder why the M25 gets clogged up?
C
Interesting - Do you not get out very often or is this some kind of project you have undertaken?
lucozade said:
hertsbiker said: Lucozade, you're right up to a point. My sim shows that if you set the cruising speed to the same for all vehicles, you get maximum flow - and zero lane changing as there is no advantage to change lane. When I tweak the speed of one car objects on the sim, it has a major effect on all the other cars. Slow it down too much, and lane hogging takes place as people "queue" to get past. Too fast, and it "surges" or yo-yo's which is also disruptive.
Interestingly (sad I know) but if I adjust the braking of just *one* car to be double that of the others, you guessed it - pile up. Likewise, too much acceleration, and the same thing.
You'd be amazed at the calculations required to simulate a 3 lane road... and then we all wonder why the M25 gets clogged up?
C
Interesting - Do you not get out very often or is this some kind of project you have undertaken?
Rofl
Surely if there was some kind of law about lorries not being allowed to overtake on certain stretches of motorway it would help traffic flow and journey time.
It seems whenever there is hard braking in the outside lane if you look ahead there's (almost) always an artic or a panel van fcuking it up for everyone else by struggling up a hill in the wrong lane.
It seems whenever there is hard braking in the outside lane if you look ahead there's (almost) always an artic or a panel van fcuking it up for everyone else by struggling up a hill in the wrong lane.
hertsbiker said: My sim shows that if you set the cruising speed to the same for all vehicles, you get maximum flow - and zero lane changing as there is no advantage to change lane.
So the variable speed limit sections (with signs saying to avoid changing lanes) on the M25 are in theory a good idea then?
Its hard to know how jammed jcts 10 to 15 would be without them, since they are always turned on nowadays.
spnracing said: Kooperkid - why should a lorry driver have to wait while car drivers don't? They have to get somewhere too.
Only wait to overtake until a more suitable downhill section. What did they used to do on 2 lane motorways? (sorry too young to remember the glory days of 2 lane m-ways)
lucozade said:Out of interest the focus on your speedometer is nothing new. I to have passed the Advanced Driving and found it incredibly difficult to maintain the speed limits exactly. I found the only way to maintain a good balance of concentration without exceeding the speed limit was to buy a car with cruise control. No fun I know but that's what this country is coming too.
Well I guess everybody is different, I find it quite easy to pick a speed and stick to it, be that 70, 90 or 120 (Germany) on the motorway. Also have an IAM pass.
When my speed varies by more than a couple of mph from my target I know I'm getting tired.
Fd
>> Edited by fergusd on Wednesday 22 January 13:07
hertsbiker said: I might publish the source code to a road simulator I have written in VB - it clearly shows that lane changing is inefficient, and that lane hogging is indeed the fastest, less stressful method of A->B travel... and strangely enough, it is our "keep left" code that makes the right hand lane get jammed up.
Incidentally, and scarily, high performance vehicles actually seem to clog the system up as they have better acceleration & braking. But that's only my simulator
C
Carl. Have you really got one? It'd be a hoot to play with. Although I despise VB, C++ is pure and beautiful!
, I can write it. It'd be a laugh to fiddle with it. How do you simulate the cars, braking etc....
fergusd said:
lucozade said:Out of interest the focus on your speedometer is nothing new. I to have passed the Advanced Driving and found it incredibly difficult to maintain the speed limits exactly. I found the only way to maintain a good balance of concentration without exceeding the speed limit was to buy a car with cruise control. No fun I know but that's what this country is coming too.
Well I guess everybody is different, I find it quite easy to pick a speed and stick to it, be that 70, 90 or 120 (Germany) on the motorway. Also have an IAM pass.
When my speed varies by more than a couple of mph from my target I know I'm getting tired.
Fd
>> Edited by fergusd on Wednesday 22 January 13:07
I learned to drive in Los Angeles and the system there seemed to be a bit more logical and civilized.
The cops didn't seem really bothered about speed per-se. I was never pulled over simply for driving over the limit and I don't know anyone who was.
The highway patrol focussed more on unsafe drivers. People weaving in and out of lanes, people driving a dramatically different speeds (faster OR slower) than the rest of traffic, people who pass on the wrong side (a pet peeve of mine - there are a lot of Brits who need to learn the concept of 'lane discipline'). Even back when the speed limit was 55mph entire groups of cars would regularly cruise the freeways at 65-70mph while cop would breeze right by to pull over someone who was following the car in front of them too closely. And they LOVED to catch drunk drivers. Some judges would let them off with a slap on the wrist (some wouldn't) but the cops loved reeling them in.
To me, that's the way traffic enforcement should be. That way, people will think of the police as their allies rather than an annoyance.
Unfortunately, when I drive in England, I'm so used to keeping the same speed as the cars around me that I routinely find myself over the limit because everyone else is too and to me, it is more important (and safer!) to keep a steady flow of traffic than it is to drive at some arbitrary speed that treats all cars and all drivers as if they were the same.
Some cars and people shouldn't be allowed on the motorway at all, much less at 70mph. Some cars/people can drive safely at 120mph.
Gassing Station | Speed, Plod & the Law | Top of Page | What's New | My Stuff