There is nothing wrong with appropriate speed limits, but these days they use a blunt "reduce them all" and "the pedestrian is always right" argument. I see the most stupid limits locally: far too slow in places, far too fast in others.
And don't forget that if you reduce speeds to 20mph or even 10mph (it will happen), you increase pollution. Pollution leads to deaths from heart and lung diseases. So you might save 1 life from a car accident, but you lose by increased deaths from pollution. But the car death is easily attributed. Unintended consequences anyone?
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At the end of the day, we are all pedestrians but I think those pedestrians that drive, exhibit a far greater understanding of safety when crossing roads on foot than those pedestrians that don't drive.
I would love to see the American ' Jay walking " type of law introduced in this country.
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pedestrians that drive exhibit a far greater understanding of safety when crossing roads on foot I would love to see the American ' Jay walking " type of law
Quite right 2cents. Drivers are far better pedestrians than some non-drivers. A driver for example will recognise when a car turning off a busy main road will get in the way of other traffic if it has to wait for some fool dawdling across the entrance to a side road.
As a driver, I notice that about a third of pedestrians are sensible and polite, making eye contact and acknowledging courteous driving, and about a third are competent but rude. Quite a lot of the rest seem to want to be run over, and their idiocy makes them terribly angry. They tend of course to blame it on drivers.
As a pedestrian, I notice the same sort of thing about drivers. About a third are good, another third OK and a third absolute carp.
Can't agree about jaywalking law though. A ghastly humourless New York cop gave me some cheek once when I was crossing a road perfectly safely, but against a red light. Quite enough of that sort of thing already.
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Surely if you slow from 30mph to 20mph and change down from 3rd to 2nd engine revs will be about the same but time taken to cover a set distance increases by 50% therefore emissions would rise (...)
The revs. don't equate to the power, though - to say that "at 3000RPM my engine uses X times more fuel than it does at 1500RPM" doesn't work out.
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The revs. don't equate to the power though - to say that "at 3000RPM my engine uses X times more fuel than it does at 1500RPM" doesn't work out.
Who said anything about power?
If you normally drive at 3rd/4th in a 30 zone then you will likely choose 2nd/3rd respectively at 20mph. That will mean the engine running at roughly the same revs, but the car could take up to 50% longer to cover the same distance... 50% longer time to travel at the same revs = 50% more pollution. Not quite as simple as that, as no journey would be all 30mph and then suddenly all 20mph, but it shows the worst case.
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I don't think 20 mph limits can be presented as a climate-saving issue - they are more to do with road safety. Used sparingly in tricky areas they are a good idea, but they shouldn't become a general replacement for the 30 limit.
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OK, then, "pollution" is not soley dependent on RPM, if you prefer it like that. "50% longer time to travel at the same revs = 50% more pollution" is wildly misleading.
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"50% longer time to travel at the same revs = 50% more pollution" is wildly misleading.
Please explain why it is misleading.
In the most simple case, if I drive down a road at 30mph at X rpm I will produce Y grams of CO2. If I now drive down the same road at 20mph at X rpm I will produce 1.5 * Y grams of CO2.
I do agree that it is more complicated than that. Most low speed journeys involve a lot of stop start and sub-30mph driving. However the general principle still holds - lower any speed limit below 50/60 mph (depending on gearing and aerodynamics) and pollution *will* increase. The exception being where you get very short breaks of higher speed limits, leading to bursts of acceleration, followed by sharp breaking, or very windy roads where speeds drop due to frequent sharp bends with long straights in-between.
Edited by TheOilBurner on 25/01/2008 at 12:25
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So if we obey the anti-car nazi councils and all take the bus, does a pedestrian still have the same chance of survival if hit by a huge great bus at 20mph?
Most modern cars are at least heading towards more pedestrian safe front ends. A bus is a mobile brick wall.
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To answer Audi Dave:
If average speeds are increased, that is AVERAGE speeds, not necessarily the ACTUAL speed across the Zebra crossing that your or my family are using to cross the road. then congestion would be reduced, journey times would be shortened and there would be a greater gap between vehicles on the stretch of road where your daughter sees her friend on the other side and runs across. Not to mention the fact that the drivers will be more alert having had a shorter journeys and also less stressed due to not being delayed in traffic.
If you extrapolate the Speed Kills message too far than all vehicles would be at a standstill. However it is not speed that kills it is hitting something that kills, reducing speed reduces the impact though does not reduce the likelyhood of the impact, to the contrary it increases the likelyhood of the impact because it introduces other factors such as congestion to name but one.
So the answer in respect of pedestrians is to seperate them from carriageways, the logic is sound - despite much higher average vehicle speeds motorways and dual carriageways are safer than normal roads because the opposing vehicles are seperated by a central barrier and pedestrians cross by bridges.
EDIT: And back to the OP's point higher average speeds mean, less congestion, shorter journey times and reduced CO2! Win Win Win!
Edited by cheddar on 25/01/2008 at 14:06
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>> EDIT: And back to the OP's point higher average speeds mean less congestionshorter journey times and reduced CO2! Win Win Win!
Say that (for instance) I recently drove between Town A and Town B, a distance or 60 miles, in 40 minutes. Are you telling me that during the journey my car generated less CO2 than it would have if the journey had taken (for instance) 65 minutes??
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Say that (for instance) I recently drove between Town A and Town B a distance or 60 miles in 40 minutes. Are you telling me that during the journey my car generated less CO2 than it would have if the journey had taken (for instance) 65 minutes??
No - the first journey would be at an average of 90mph and the latter at 55 mph !!!
The point is that, say, a 30 mph average slowing to 20 at crossings, stopping for a few secs on occasions and cruising at 40 or 50 uses less fuel than a 15 mph average stop-start, lots of sitting at standstill, at idle getting frustrated etc.
Edited by cheddar on 25/01/2008 at 14:48
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However it is not speed that kills it is hitting something that kills reducing speed reduces the impact though does not reduce the likelyhood of the impact to the contrary it increases the likelyhood of the impact because it introduces other factors such as congestion to name but one.
Cheddar
Your thinking is very unscientific. Reducing speed DOES reduce the likelihood of an impact. A lower speed translates into more thinking time (to avoid the impact) and a shorter stopping distance (the energy in the vehicle, and hence the stopping distance, are related to the SQUARE of the velocity). I also fail to see how 'congestion' makes crashes more likely.
Now, on the fuel consumption vs. speed argument - there is an optimum speed, at which fuel consumption is at a minimum. This arises because the drag factors on the vehicle are not linearly related to speed - they are related to the speed raised to some power (e.g. wind resistance, bearing drag, tyre drag etc). Typically fuel consumption (and C02 emission) is at a minimum somewhere around 50-60mph.
There has been a vast amount of research into road congestion over the years, a lot of it done in Japan where they have done all kinds of experiments into flow control on their expressways.
Increasing speed DOES NOT reduce congestion.
Congestion occurs when the volume of traffic on the road exceeds its capacity. The capacity of a road falls with increasing speed (following distance increases). As traffic density increases then speed falls (not the other way around). At some point steady flow cannot be maintained and so we get congestion - a breakdown of flow and 'stop start'.
Typically this congestion occurs because traffic is arriving at a piece of roadway faster than it can leave it - usually because traffic is moving from high speed roads to lower speed roads or having to stop at junctions, a road 'pinch point' etc etc.
Increasing speed limits would reduce journey times on roads that are already free flowing. On roads that are already congested they would more likely just deliver cars more quickly to the bottleneck.
What the Japanese have found to be the best solution is to 'flow manage' the traffic by varying the speed limits to keep traffic on busy roads at below its maximum capacity, and avoiding it stopping completely.
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Aprilia
You need to consider the effect from the begining to end of each journey and not just from point A to point B on a stretch of road with vehicles entering it and exiting it. If the AVERAGE speed of all vehicles on the road network could be increased by 10% then journey times would reduce by iro 10% so there would be iro 10% less vehicles on the road at anyone time. 10 mile journey ay 20mph ave = 30 mins, at 22mph ave = 27.5 mins.
Therefore at the points where vehicles are correctly slowed to 20mph past a school there would be less of them so less bottlenecks, more gaps in between vehicles so better line of sight, less frustrated drivers etc etc.
Remember I am talking about average speeds over a journey.
And this could be acheived without raising limits beacuse average speeds are much lower than the actual posted limits, less that 50% of the limit in most urban areas.
>>Typically fuel consumption C02 emission) is at a minimum somewhere around 50-60mph.>>
And it is also lower at a 30 mph average with few stop and starts than at a 15 mph with ages at stanstill.
>>Increasing speed DOES NOT reduce congestion. Congestion occurs when the volume of traffic on the road exceeds its capacity. >>
Increasing speed CAN reduce congestion if the road's capacity is inline with the expected average speeds.
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Aprilia You need to consider the effect from the begining to end of each journey and not just from point A to point B on a stretch of road with vehicles entering it and exiting it. If the AVERAGE speed of all vehicles on the road network could be increased by 10% then journey times would reduce by iro 10% so there would be iro 10% less vehicles on the road at anyone time. 10 mile journey ay 20mph ave = 30 mins at 22mph ave = 27.5 mins. Therefore at the points where vehicles are correctly slowed to 20mph past a school there would be less of them so less bottlenecks more gaps in between vehicles so better line of sight less frustrated drivers etc etc.
No, this is absolutely not the case. Think it through...
Let's say we increases all speed limits by 10mph. In areas of the country where there is no congestion there would probably continue to be no congestion - journeys would be completed a little more quickly (althought there might be a few more accidents) and there might be fewer cars on the road in these areas.
In areas that are already congested the traffic cannot maintain the existing speed limit, let alone the 'new' one which is 10mph higher. The higher speed limit therefore simply delivers cars more quickly to the congestion hot-spots. The fact that there is less traffic on the road elsewhere in the country is immaterial. Traffic does not spread itself out uniformly over the road network and the congested areas remain congested.
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No this is absolutely not the case. Think it through...
I have !
Aprilia, you are missing two key points:
1/ If journey times are reduced there will be less cars on the road at any one time.
2/ My last sentance, a road's capacity needs to be inline with the expected average speeds. So rather than reduce speeds further, instead allieviate the bottleneck.
I.E.
Today we have 30mph limits yet the average speed through these urban areas is less than half of that, so what good would a blanket lowering of the limit do? All it would mean is that at the points where traffic can now do 30 it would no longer be able to do so thus would mean an increase in journey times and increased congestion.
The objective surely needs to be to clear the bottlenecks so reasonable average speeds can be acheived along with all of the advantages that I have mentioned before.
It needs an inteligent appraoch using techniques such as variable limits in the vicinity of schools as opposed to 20mph 24/7 etc.
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>> 1/ If journey times are reduced there will be less cars on the road atany one time.
Increase speed to infinity, decrease number of cars to 0.
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Actually all the report does is prove that at a constant speed CO2 emmissions are reduced - probably 40 in 5th would be even more ecconomical - so do we raise all limits to 40?!
It doesn't justify higher limits - the report actually went on to say that average speed cameras were better than humps - and the producers of the report, the AA, actually said they would be in favour of them!!
It also acknowledged that lower limits such as 20 or 30 are required - it was more to do with how they were policed and reduction of CO2 in such areas where they were needed - the heading to this thread is mightily misleading! And true to form people have gone off on their hobbyhorses!
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- and the producers of the report the AA actually said they would be in favour of them!!
there's no message that should be taken from that, they're now a private company that sell insurance.....they are no longer a motorists organisation as they used to be in the past
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20mph limits and speed humps are a road safety matter - nothing to do with saving fuel. A car WILL use more fuel when operating in low gear/higher rpm.
We need speed humps and 20mph limits in certain urban areas because a significant proportion of drivers WILL NOT drive appropriately in risky areas. They don't care.
I have posted before that I am a governor at a local primary school. The headteacher and governing body are campaigning for a 20mph limit and/or humps outside the school because of the traffic risk. Each morning and afternoon the road is strewn with poorly parked vehicles - many 4x4's (parents who will not follow repeated polite requests from the school to 'park responsibly') - and other vehicles come snaking through at 30+mph. I don't feel too safe crossing myself, let alone a 5 year old. And that's exluding the odd 'nutter' in a delivery van who comes blasting through at 50mph....
Actually, HJ sums up the situation quite nicely in his recent road test of the Isuzu Rodeo..." at the same time as the QE7s, X5s, GLs, XC90s and all the other battle wagons that come out to pick up the next generation of city brokers and bankers from their posh fee-paying schools, mothers chatting incessantly into their Motorola Razors and i-phones as they charge down the rat-runs through the council estate, anti-hijack locks applied. My Rodeo coped with this perfectly."
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>>are campaigning for a 20mph limit and/or humps outside the school because of the traffic risk.>>
You have my vote Aprillia, my point is that it should be 20mph, or even 15 mph between 8 & 9AM and 3 & 4PM and say 30 or 40 at other times.
20mph 24/7 when the risk is for maybe 5 hours a day, 5 days a week is not sensible and is detrimental in other respects.
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We need speed humps and 20mph limits in certain urban areas because a significant proportion of drivers WILL NOT drive appropriately in risky areas. They don't care.
Yup. Trouble is, they aren't bothered about humps and 20 limits either. We have both (and pinch points, raised surfaces and similar) in our neighbourhood and at various places in the rest of the village and the local divs regard all of it as a sort of real life rally game. They still tear around everywhere at 40+, gobbing off at anyone having the misfortune to happen to be in front of them, and in some cases trying to get air off the humps.
Meanwhile the rest of us have to negotiate all these suspension-wrecking obstacles in the roadway, as a result of which I have had to have the Mondeo's tracking done twice in 5 months, and the Panda is now making noises suggestive of unhappy subframe bushes (wand we go carefully, too - goodness knows how bad they would both be if we didn't). All caused by "traffic calming" that does no such thing.
Someone further up drew the comparison between 90% of people run over at 20 mph surviving and 85% dying if hit at 40 (I may not have the exact figures there, the post isn't in view). Do the statistics say how many of the 90% of survivors suffered permanent or long-term disability as a result?
I have heard it said on a number of occasions that for the victim's family, that can be worse for them to deal with than would be the case with the death. I stress that I have no personal experience of this (and it is one of a large number of things that I hope I am spared), but if this is so, then it is disingenuous to suggest (as the road safety ads do) that everything will be fine and dandy if the victim survives.
The answer to all this, as with everything else, is better road policing, but that's a whole different debate...
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Yup. Trouble is they aren't bothered about humps and 20 limits either. We have both (and pinch points raised surfaces and similar) in our neighbourhood and at various places in the rest of the village and the local divs regard all of it as a sort of real life rally game. They still tear around everywhere at 40+ gobbing off at anyone having the misfortune to happen to be in front of them and in some cases trying to get air off the humps.
Yes, there are some drivers who will try to 'ignore' speed humps - but a lot DO slow down. I have to negotiate a road with a large number of speed humps each day and I see very few drivers blasting over them. Usually its the delivery van drivers IME.
Meanwhile the rest of us have to negotiate all these suspension-wrecking obstacles in the roadway as a result of which I have had to have the Mondeo's tracking done twice in 5 months and the Panda is now making noises suggestive of unhappy subframe bushes
I think this is more a reflection on those vehicles. My last Merc was sold with 120k and went over a fair number of humps each day - never had any suspension work. Similarly my wife had a Nissan Primera that lasted about 8 years of daily speed humps without a problem.
(wand we go carefully too - goodness knows how bad they would both be if we didn't). All caused by "traffic calming" that does no such thing. Someone further up drew the comparison between 90% of people run over at 20 mph surviving and 85% dying if hit at 40 (I may not have the exact figures there the post isn't in view). Do the statistics say how many of the 90% of survivors suffered permanent or long-term disability as a result?
Some might take the view that better to survive than not....?
but if this is so then it is disingenuous to suggest (as the road safety ads do) that everything will be fine and dandy if the victim survives.
Interesting that anyone could argue that higher speed might be beneficial by assuring death rather than disability..
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I think this is more a reflection on those vehicles. My last Merc was sold with 120k and went over a fair number of humps each day - never had any suspension work. Similarly my wife had a Nissan Primera that lasted about 8 years of daily speed humps without a problem.
On that basis perhaps we've just been unlucky - what I should perhaps have mentioned is that we have more than our fair share of dreadful road maintenance in this county as well as all this - that is, I acknowledge, likely to contribute too.
Some might take the view that better to survive than not....?
I can see how there could be circumstances in which that might actually be debatable - but we'd get very off-topic and philosophical there.
Interesting that anyone could argue that higher speed might be beneficial by assuring death rather than disability..
I'm not suggesting that - I think we both know that no sane person would. It were better that no accident took place at all and no-one could convincingly argue the contrary.
What I mean is that the adverts are facile (you have previously seen, and commented on, other views of mine on their content!) in suggesting that the mere fact that the victim is more likely to survive makes everything better. It doesn't - it has the potential to make the accident just as horrible in other ways.
I think the point I'm trying to make is that slowing people down is only part of it and better hazard awareness and driver education is just as (if not more) important, as is throwing the book at people who cause danger in the sort of situations that you described above (i.e. school chucking-out time). The hazard perception test is a step in the right direction there, but doesn't go far enough imo.
I am conscious of contributing to "topic drift" here - apols.
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my theory is that the more sanitised you make our roads, the less the people using them, be they drivers or predestrians, think for themselves and take due risk avoidance
i'm not suggesting for one minute we have a complete 'free for all' before my words are twisted
just a happy medium
a blanket 20mph limit is not a happy medium in my view, it is ridiculous...although i have no problem at all adhering to that when the kids are on the way to/from school
variable limits for specific roads only to cover schools, hospitals etc...and sensible limits to be set for all roads, if necessary increasing them upwards instead of incessantly downwards
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If only they were all like you Wp...
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If only they were all like you Wp...
i keep telling my wife that, but she just laughs at me...:-)
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I agree 100% Westpig ..........
................ cos that is exactly what I have been saying !
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I agree 100% Westpig .......... ................ cos that is exactly what I have been saying !
I know, but some people take a bit of 'teaching' to understand the reality, so i re-hashed it and presented it again
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A cyclist was knocked off his bike near to me a few weeks ago. Incident still being investigated and no details have been released to the public.
In tonights paper, the usual letter has appeared. The letter immediately puts all the blame on the motorists, states that in the rural area where we live 'there is no need to rush' and a blanket 20mph limit should be imposed.
I didn't know whether to laugh or cry.
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Alternative could be to ban all cyclists.
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Cyclist..
No lights ?
turning right / left with out checking behind ?
drunk ?
Perish the thought they would be treated as anything other than 'the victim ".
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No probably none of those. More likely the all time classic of a vehicle pulling out of a junction without looking properly, the 'sorry mate didn't see you accident', sadly familiar to anyone who has swung a leg over a bike. Government figures state that 2 out of 3 cycling accidents are caused by car driver error, cyclist error was usually young cyclists. So don't know about that particular collision so will wait to see, could be the cyclist error or probably (with respect to these figure) will be motorists error. So actually 2cents, cyclist generally are the 'victim'
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All the sins of delinquent cyclists could be arraigned at delinquent car drivers. One set are likely to survive, the other are not. In Europe the onus is on the heavy brigade to act responsibly: having to cycle or walk may be a result of choice, or illness, youth, old age or poverty. It should not be penalised. Returning to the issue of sanitisation, roads are not the sole property of motorised traffic, but are shared except for M:ways and the iron road. The highway is open to everyone other than the motorist. Indeed, its the motorist who has to prove a right to use the highway. Increasing car traffic and increasing handling capability has caused many roads to be perceived as dangerous to pedestrian and cycle traffic. Fewer walkers, fewer cyclists, means less expectation of slower traffic, and more gung-ho/sloppy driving without a thought for non-motorised vehicles.
Not a virtuous circle. How many testosterone-ridden youths (16% of mileage, 56% of fatalities) are capable of considering anything but the moment? How many school-run mums have ever ridden a bike?
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20 limits past schools dosent need 12 humps better part time electronic 20 sign and then one those your speed is ? sign. sugest this to your council if they threaten humps
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Our local area council is experimenting with such part-time electronic speed-limit signs outside schools. I think that they are "on" for half an hour before school starts, and again for half an hour after school finishes. As they are experimental, the policing is a bit heavier than normal too, which may explain some of the success of the signs.
In the local village, there are a couple of places where pedestrians like to scamper across the road rather than walk another 25 yards to the pedestrian crossing, so much so that the council has installed warning signs reminding pedestrians that, quote - Motorists have right of way - unquote.
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You may wish to remind the LA that there is no such right of way: from the Introduction to the Highway Code on general rules for drivers and riders: sections 103 -158 "This section should be read by all drivers, motorcyclists, cyclists and horse riders. The rules in The Highway Code do not give you the right of way in any circumstance, but they advise you when you should give way to others. Always give way if it can help to avoid an incident."
Edited by nortones2 on 26/01/2008 at 10:59
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Nortones - suspect Kiwi Gary is subject to NZ rather than UK hoghway regs.
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Aah: perhaps so! So NZ is not such a paradise:)
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Aah: perhaps so! So NZ is not such a paradise:)
for me that puts it firmly back into the paradise zone
when i'm walking i have no problem at all with the fact i need to give way to cars etc on a road......apart from a common sense angle for personal safety, it allows the traffic to flow freely.......every now and then there's crossing points etc, so i have to use my noddle and choose my timings, allowing the motor vehicle to keep going...what's wrong with that?
the problems arise when pedestrians stroll straight across as if they have the God given right....or kids run out on impulse which can be through lack of proper training (although i'd willingly accept kids go through a phase when it hasn't yet been instilled in them & no parent could reasonably achieve it)
what's wrong with a pedestrian being wary and giving way to the motor vehicle? (apart from controlled crossings etc)
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Its not as simple as that, WP. Wariness, yes, but right of way for the motor is a figment. Has to be a degree of tolerance for the pedestrian and other road users. Take the issue of a turning from one road into another. The pedestrian whether fleet of foot, or sound of sight and hearing or not, might start from a position where the road is clear, but not get across in time. In one of our local towns, a junction where there is a choice of straight on, or a downhill swoop, can cause conflict where drivers fail to signal. No signal implies an undeviating course, but frequently the driver swings round as the pedestrian is part way across. Highway code sets out the advice and rules: there is no right of way for the car. Clearly that doesn't give the pedestrian the right to obstruct either because they don't have right of way either, except at controlled crossings. I'm merely objecting to the idea of right of way: this is not a line of thought that is helpful in our cities and our rural roads. Better to have some degree of tolerance.
Edited by nortones2 on 26/01/2008 at 15:40
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It is interesting to note that throughout the debate here that people refer to roads even in residential areas. The DfT is moving with the times in the urban design and more enlightened highway engineering community to talk of streets rather than roads, especially for residential streets and high streets. Their new Manual for Streets is the new set of guidelines for the design of such thoroughfares. It will see a big change in the approach to urban highways. The previous Highway orientation to easy vehicle traffic flow and to enforce rigid separation of pedestrian and vehicle is being replaced by a general approach that there are many users of streets and that the hierarchy of users starts with pedestrian, cyclist and public transport user at the top and vehicle traffic at the bottom. I believe it is calling also for a 20mph limit in all residential streets.
What you will see is a big increase in the removal of "cattle pen" barriers/railings (as is happening even in busy areas such as London road junctions and all along Kensington high street - led to a reduction in accidents) and in some town centres and residential streets the idea of a common shared surface where nobody has priority at any time.
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