Author Topic: Driving law proposals could see motorway speed limits raised to 100mph to 'reduce congestion'  (Read 6468 times)

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cp8759

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I practice law in the Traffic Penalty Tribunal, London Tribunals, the First-tier tribunal for Scotland, and the Traffic Penalty Tribunal for Northern Ireland, but I am not a solicitor nor a barrister. Notwithstanding this, I voluntarily apply the cab rank rule. I am a member of the Society of Professional McKenzie Friends, my membership number is FM193.

Quote from: 'Gumph' date='Thu, 19 Jan 2023 - 10:23'
cp8759 is, indeed, a Wizard of the First Order

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tonys

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Did you mean to post this on the 1st, in the morning?

cp8759

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Did you mean to post this on the 1st, in the morning?
No?  ???
I practice law in the Traffic Penalty Tribunal, London Tribunals, the First-tier tribunal for Scotland, and the Traffic Penalty Tribunal for Northern Ireland, but I am not a solicitor nor a barrister. Notwithstanding this, I voluntarily apply the cab rank rule. I am a member of the Society of Professional McKenzie Friends, my membership number is FM193.

Quote from: 'Gumph' date='Thu, 19 Jan 2023 - 10:23'
cp8759 is, indeed, a Wizard of the First Order

guest968

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Given that (on dry roads) the advice is to maintain a 2 second gap then the faster the traffic the longer the gap has to be, so as speeds increase you actually get fewer cars on a given length of road.

At any given moment in time, each lane of a road has capacity for about 24 cars per mile (assuming average car length of 14.44') at 70mph, and about 17 per mile at 100mph.

Because car lengths remain the same though, you can pass more cars down the road at higher speeds. But not by much - past any given point you can get about 1682 cars per hour at 70mph, and 1716 at 100mph.

The reality though is that you're always going to get bunching up and sudden slow-downs of traffic, particularly when volumes are high, and the faster the "free-flowing" traffic is the worse the temporary blockages get (people into queueing theory can probably explain why).

That's why during peak times temporary speed limits are used to slow traffic down, to minimise the number and severity of temporary blockages, and to allow ones which arise to clear quicker by reducing the rate at which new vehicles arrive.

And that idea would work better than it does if people stuck to the temporary limits instead of stupidly and selfishly ignoring them because they can't see why it's needed.  That's the whole point - you can't see why because the why is 5 miles down the road.  Thank heavens for the increased use of non-film ANPR gantry cameras which make it impossible for drivers not to follow temporary speed limits.

I suspect that upping the limit would actually make things worse, not better.
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andy_foster

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That is a somewhat confused post - mostly correct but seemingly contradictory.

For the purposes of maximising road capacity, *if* the braking distance increases exponentially with speed as per the highway code (my opinion of which is well documented), the optimum speed is about 11mph.

If a road is below maximum capacity, journeys will be shorter at higher speeds.

However, *if* the "two second rule" is applied, rather than the highway code distances, the 'length' of a vehicle effectively becomes shorter (measured in time taken for its length to pass a point), and maximum throughput is just below whatever speed the French cars start to blow up.

Suggesting that motorists who have scant regard for often arbitrary temporary speed limits are variously stupid and selfish is perhaps not the best way to ingratiate yourself with a motoring forum - although perhaps that's the idea.

Temporary limits at rush hour to maximise traffic flow are largely a good idea, let down by the prevalence of arbitrary and pointless speed limit reductions 'just in case'. Today Aesop would be castigated for his portrayal of the boy on the grounds that there might have been a wolf anyway, and you can't be too careful. You can, and that is why temporary speed limits to increase traffic flow don't work.
I am responsible for the accuracy of the information I post, not your ability to comprehend it.

cp8759

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Forget about this rush hour nonsense, it's unlikely traffic will be able to travel on any motorway at the maximum legal limit at rush hour anyway.

But being able to do 100 mph at 11 pm would save me hundreds of hours of slow driving per year (70 mph is slow in my book).
I practice law in the Traffic Penalty Tribunal, London Tribunals, the First-tier tribunal for Scotland, and the Traffic Penalty Tribunal for Northern Ireland, but I am not a solicitor nor a barrister. Notwithstanding this, I voluntarily apply the cab rank rule. I am a member of the Society of Professional McKenzie Friends, my membership number is FM193.

Quote from: 'Gumph' date='Thu, 19 Jan 2023 - 10:23'
cp8759 is, indeed, a Wizard of the First Order

tonys

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It's not that long ago that an increase to 80mph was considered and rejected. At that time one of the strange arguments was that drivers currently exceeding 70 would no longer be breaking the law. In other words the supporters were suggesting people would obey the increased limit, rather than drive 11mph faster.

As for that headline "Driving law proposals could see motorway speed limits raised to 100mph to 'reduce congestion" it's written to suggest that this proposal (not proposals by the way) comes from someone actually likely to influence the law.

Then again look at their other headlines. An article about fuel price rises due to oil prices, supply chain, and exchange rate has the headline "Petrol and diesel drivers punished by supermarkets"

guest968

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That is a somewhat confused post - mostly correct but seemingly contradictory.

For the purposes of maximising road capacity, *if* the braking distance increases exponentially with speed as per the highway code (my opinion of which is well documented), the optimum speed is about 11mph.

If a road is below maximum capacity, journeys will be shorter at higher speeds.

However, *if* the "two second rule" is applied, rather than the highway code distances, the 'length' of a vehicle effectively becomes shorter (measured in time taken for its length to pass a point), and maximum throughput is just below whatever speed the French cars start to blow up.

HC stopping distances are not the same as the spacing between cars in moving traffic, because the expectation is that the car in front of you is not going to go from <whatever> mph to zero instantly and without warning.  The expectation is that a driver will be looking as far ahead as possible and thus see anything requiring braking only a few seconds after the car in front, and that that one will take some time to stop.  The HC stopping distances are the same as a 2s gap at 40mph, less below, and greater above.

Re the length of a vehicle, if you add 14.44' to the length of a 2s gap at Xmph then you have the distance between the front of one car and the front of the next, which you use to calculate how many cars will fit onto a given length of road, and the total package of [car+gap] will take a calculable amount of time to pass a point, so that tells you how many can pass a point in a given amount of time.
 

Suggesting that motorists who have scant regard for often arbitrary temporary speed limits are variously stupid and selfish is perhaps not the best way to ingratiate yourself with a motoring forum - although perhaps that's the idea.
Of course it's not, but I'm not trying to ingratiate myself, nor should I have to.

I'm well aware that this site has a political bias, and that it is one that I do not share, and for the avoidance of doubt, I'm happy to nail my (relevant to this site) colours to the mast.

I am in favour of congestion zones, low emission zones, low traffic neighbourhoods and 20mph speed limits in built-up areas.

I think 15-minute cities are a great idea.

I think that where beneficial to public transport, of course buses etc should be prioritised over private vehicles for road space, traffic light phasing, no entry/right-turn/left-turn/etc signs.

I think that this whole "war on the motorist" idea is complete swivel-eyed conspiracy b******s, believed by people who have swallowed the cynical self-serving lies of populist politicians and the right-wing red tops.

Does this mean that I think cp8759 is "Tory scum"?  Of course not.

Does it mean that he, or others, think I'm "socialist scum" and should refuse me their help if I needed it?  I would sincerely hope of course not.

[And I'd like to point out, in passing, that the introduction of congestion zones/LEZs/LTNs/etc do not follow party political alignments]

Does this mean that I think the authorities should be allowed a bit of slack in their adherence to the rules and regulations for signage, camera authorisations, notice wording and serving, etc?  Of course not.  And the flip-side of that is the of-course-not to whether drivers who ignore what they feel are often arbitrary temporary speed limits have right on their side.

As for  "stupid and selfish", I wholeheartedly stand by that.  How many times do you see posts on various internet fora whinging about a speed limit being reduced when the traffic was light and flowing freely?  Stupidity as that tries to deny the reality of a problem 5 miles ahead which is being tackled by reducing the arrival rate of new cars.
 
How many drivers expect other ones to move left into a gap under 4 seconds long so that they can overtake, and get very headlamp-flashy and aggressive if they don't?  Selfish.

Does every driver consider the reality of what the 2s rule means?  How long that gap actually is?  Extend the principle to doubling it in adverse weather, and think of a line of HGVs doing the legal maximum of 60mpg in the left-lane of a 2-lane motorway or dual carriageway, and a car driver overtaking them at 65mph.   A 70mph driver coming up behind him has to recognise that the shortest gap he can possibly pull into is 8 seconds at 60mph which is 704', over ⅛ of a mile.  If he doesn't, he's stupid.  If he believes that the guy in front should move over even if the gap isn't that long, he's selfish.  If he doesn't allow time for the 65mph driver to close in on the vehicle then in front of him, i.e. allow an even longer gap, but expects him to drop his speed to 60 to allow him to overtake, more selfishness.
 
Look at all the drivers who regard 20mph speed limits, low-emission zones, low traffic neighbourhoods, congestion zones, etc as some ulterior-motive war on motorists to take away their freedoms.  Stupid.

Look at all the drivers who decry all those things because they stop them driving what they want, where they want, when they want, and how they want, no matter how popular and proven the benefits are to people who are not motorists.  Selfish.

Sorry, Andy, but there really are a lot of stupid, selfish motorists out there.


Temporary limits at rush hour to maximise traffic flow are largely a good idea, let down by the prevalence of arbitrary and pointless speed limit reductions 'just in case'.
Do you know that they are arbitrary and pointless, or is it just that their point is obscure to you because you don't have knowledge of all the facts?

Do you not believe that prevention is better than cure?


Today Aesop would be castigated for his portrayal of the boy on the grounds that there might have been a wolf anyway, and you can't be too careful. You can,
Every mile of road reduced to 50 from 70 because on balance it is judged to be beneficial "costs" you 21 seconds.

21 seconds.

What kind of life do you lead where that is a burden too onerous to bear?

A 10-mile stretch costs you less time than it takes to make a cup of tea.


and that is why temporary speed limits to increase traffic flow don't work.
There is a sound theoretical basis for them, and they might be more effective if there was greater observance of them.

Plus, "work" has to be viewed as the aggregate effect on tens of thousands of motorists over several miles and a time possibly measured in hours, not just one person's individual experience of a few miles at the cost of a few minutes.
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guest968

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It's not that long ago that an increase to 80mph was considered and rejected. At that time one of the strange arguments was that drivers currently exceeding 70 would no longer be breaking the law. In other words the supporters were suggesting people would obey the increased limit, rather than drive 11mph faster.

As for that headline "Driving law proposals could see motorway speed limits raised to 100mph to 'reduce congestion" it's written to suggest that this proposal (not proposals by the way) comes from someone actually likely to influence the law.

Then again look at their other headlines. An article about fuel price rises due to oil prices, supply chain, and exchange rate has the headline "Petrol and diesel drivers punished by supermarkets"
It's GB News - what do you expect?

Hippocrates

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My views for what they are worth.

1. I do not subscribe to the view re any political bias arguments because I have met cp8759 (with whom I work closely) and Andy Foster several times. Our exchanges of views have been frank yet polite. I am a musician and work in terms of the universal language of mankind (Longfellow). I do not care one iota what politics one follows. I have played in the Herodus Attica Theatre in Athens 1975 with the RPO. I have played squash (1978-1980) in Politea (north of Kifissia) from where one can see the Parthenon. Many people do not understand the root meaning of polis.
2. I have driven many thousands of miles at speed on various high-powered motorcycles. In Europe as far as Greece. 1981-1987 on the Yamaha XJ650 Turbo, Honda CX500 and Honda VF750SC, in reverse order. And in my Renault convertible and other cars thrice to Kos/Kefalonia. 2001, 2002 and 2013. The latter in three days to Thessaloniki and with one stop in Stubai Tal. (Krossbach). Near Brenner pass. The Inglorious Bastards and all that.
3. In 1997 en route to Surbiton on the Yamaha from Portsmouth (Lovedean) I had a blow out in my rear tyre (some idiot had replaced the tyre with a tubed one and had not cleaned the inside of the tyre!). Tubed tyres do not deflate so fast. I had to use all of my experience to stay alive: very little back brake, go through the gears (which many car drivers do not) and use mostly the front brake.
4. In 1981, on the Honda CX500 (which I bought having sold a rather nice Italian violin :-\ ), I had a puncture somewhere between Venice and Ferrara. Being resourceful, I carried a pump with inflatable foam, bought some chewing gum and super glue which got us to Ferrara.
5. I have driven at speed in Germany many times - nichts schneller 130 km - and have observed nutters flashing one from the back.
6. I have driven to Interlaken from Zeebrugge in 12 hours. 
7. I have driven from Brindisi to Venice in 12 hours.

In light of all this experience, I am not inclined to sign at present. Also:

8. Whichever speed limit is legalised, people will always go over it!

Another Petition should be made in my opinion to penalise the idiots who muck about in the overtaking and fast lanes apparently thinking they are driving a hearse.  :'(
« Last Edit: April 13, 2024, 12:13:06 am by Hippocrates »
There are known knowns which, had we known, we would never have wished to know. It is known that this also applies to the known unknowns. However, when one attends a hearing, Mr Rumsfeld's idea that there are also unknown unknowns fails to apply because, anyone who is in the know, knows that unknown unknowns are purely a deception otherwise known as an aleatory experience or also known as a lottery. I know that I know this to be a fact and, in this knowledge, I know that I am fully prepared to present my case but, paradoxically, in full knowledge that the unknown unknowns may well apply.
"Hippocrates"

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Please sign my petition to equate moving traffic law with bus lane law so London councils MUST attend hearings when required:

https://petition.parliament.uk/petitions/701491

guest968

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But being able to do 100 mph at 11 pm would save me hundreds of hours of slow driving per year (70 mph is slow in my book).
Yes - if each year you spend about 335 hours driving 23,450 miles at a steady 70mph (in addition to all the other hours driving further at lower speeds) then your saving if you could do that 23,450 miles at 100mph instead would just tip over 100 hours.

Once you're over 100 hours you can legitimately say you are "in the hundreds", but there is a argument that a common interpretation of "hundreds" means at least an integer multiple of hundreds, not anything over 100, so a threshold of 200 hours, i.e. 667 hours driving  46,690 miles at a steady 70mph vs 466.9 hours at a steady 100.

But however you slice it, you might like to try installing a GPS journey tracker on your phone, and gather actual data on how much of your journeys you spend at an unimpeded 70mph, and then factor in an honest appraisal of whether you could really have covered the same ground at an unimpeded 100mph, given the realities of other traffic, the weather, the fact that it's dark, etc.

You might be surprised.

Also, remember that the saving in time will cost you.  In theory power required goes up with the cube of speed. 100/70 = 1.43.  1.43³ = 2.92, so it takes nearly 3 times as much power to travel at 100 compared to 70.  Assuming constant efficiency, fuel consumption is proportional to power output so you'd be using 2.92 x more fuel to go 1.43 x faster, i.e. 2.92/1.43 = 2.04 times less efficient, meaning your mpg will drop to 1/2.04, so basically 50% of its figure at 70mph.

Your 100 hours saving will cost you twice as much in fuel over those 23,450 miles. 

Your car may well be able to give you pretty accurate consumption figures at a steady 70, especially as it would be measuring over a period of hour(s).  If so you should be able to estimate the cost of doing 100 instead of 70, and see if it is still as attractive.

cp8759

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Another Petition should be made in my opinion to penalise the idiots who muck about in the overtaking and fast lanes apparently thinking they are driving a hearse.  :'(
There's already a law against that. Maybe it should be subject to civil enforcement, with TFL given the relevant powers to enforce it on the M25? It would certainly help plug the recent budget hole from the 900 appeals they lost.
I practice law in the Traffic Penalty Tribunal, London Tribunals, the First-tier tribunal for Scotland, and the Traffic Penalty Tribunal for Northern Ireland, but I am not a solicitor nor a barrister. Notwithstanding this, I voluntarily apply the cab rank rule. I am a member of the Society of Professional McKenzie Friends, my membership number is FM193.

Quote from: 'Gumph' date='Thu, 19 Jan 2023 - 10:23'
cp8759 is, indeed, a Wizard of the First Order

cp8759

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Your 100 hours saving will cost you twice as much in fuel over those 23,450 miles. 
I'm fine with that (also considering that a higher limit doesn't mean one has to drive faster, it's just an option). You also have to factor in that driving at a more sensible speed is more enjoyable, and I'd rather be at my destination sooner rather than later given that I'm not getting any younger.

Frankly if it were up to me the motorways would have no limit at all, in Germany I found 110 / 115 mph brought a fair balance between making progress and fuel stops.
I practice law in the Traffic Penalty Tribunal, London Tribunals, the First-tier tribunal for Scotland, and the Traffic Penalty Tribunal for Northern Ireland, but I am not a solicitor nor a barrister. Notwithstanding this, I voluntarily apply the cab rank rule. I am a member of the Society of Professional McKenzie Friends, my membership number is FM193.

Quote from: 'Gumph' date='Thu, 19 Jan 2023 - 10:23'
cp8759 is, indeed, a Wizard of the First Order

guest968

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1. I do not subscribe to the view re any political bias arguments because I have met cp8759 (with whom I work closely) and Andy Foster several times. Our exchanges of views have been frank yet polite.
Without trying to re-litigate old cases, all I can do is to relate my experience.

I described people who hate Sadiq Kahn because of the colour of his skin and/or his religion as “knuckle-draggers” – removed.

A while ago I suggested (that was all) that we should be mindful that John Lyon’s campaign against Bristol’s CAZ penalties might not be entirely motivated by a purist desire for scrupulously correct legalities, and that given his track record of opposing other traffic control measures he might be one of those people who subscribes to the “war on the motorist” belief, and is simply opposed to anything which stops him driving when, where, how, and in what, he likes.   

Removed, and a complaint made against me.

Hippocrates

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Have a nice weekend everyone.  I have a couple of case to win next week.
There are known knowns which, had we known, we would never have wished to know. It is known that this also applies to the known unknowns. However, when one attends a hearing, Mr Rumsfeld's idea that there are also unknown unknowns fails to apply because, anyone who is in the know, knows that unknown unknowns are purely a deception otherwise known as an aleatory experience or also known as a lottery. I know that I know this to be a fact and, in this knowledge, I know that I am fully prepared to present my case but, paradoxically, in full knowledge that the unknown unknowns may well apply.
"Hippocrates"

URGENT

Please sign my petition to equate moving traffic law with bus lane law so London councils MUST attend hearings when required:

https://petition.parliament.uk/petitions/701491