big road programs are justified on economic benefit thru reduced congestion
By and large, big road programmes are no longer justified at all, it's now about reducing traffic levels and increasing public transport use, walking and cycling. Good all round!
cynic-al - Membertwo second gap let alone keep to the speed limit.
Is this recommended (by anyone other than TJ) or even practical in a city?
My point made in one! Two second gap is the recomended - by highway code, IAM etc etc. No one does - just try counting it. Most of the time you re lucky if you get 1 second.
Al - actually average speeds rise if people do this as you don't get the speed up and slow down concertina effect - same as a 20 mph limit around town increases average speeds on congested roads
Druidh - YGM about hillwalking. I'll be driving
No one does - just try counting it. Most of the time you re lucky if you get 1 second.
I try to do it on the way home when I take the m-way. Usually get 3 or 4 cars jumping into the gap just before their junction 
Oh dear.....*TJ FAIL ALERT*
WOOP WOOP WOOP!!!
126
Stopping Distances. Drive at a speed that will allow you to stop well within the distance you can see to be clear. You shouldleave enough space between you and the vehicle in front so that you can pull up safely if it suddenly slows down or stops. The safe rule is never to get closer than the overall stopping distance (see Typical Stopping Distances PDF below)*
allow at least a two-second gap between you and the vehicle in front on roads carrying faster-moving traffic and in tunnels where visibility is reduced. The gap should be at least doubled on wet roads and increased still further on icy roads
remember, large vehicles and motorcycles need a greater distance to stop. If driving a large vehicle in a tunnel, you should allow a four-second gap between you and the vehicle in front
*12-23M at 20-30mph - fair enough, not generally complied with I'd say.
EDIT:
Al - actually average speeds rise if people do this as you don't get the speed up and slow down concertina effect - same as a 20 mph limit around town increases average speeds on congested roads
WTF? In town?
I can see that glenp, my guess is rush hour would last about 3 times as long and few serious accidents would be averted.My point double-made! Of course congestion doesn't go up - you still get there at the same speed, probably faster because you don't have to brake when the car in front dabs his brakes (because the car in front of him…). The gap is in seconds remember - slow moving traffic means the distance is small.
Sadly congestion is getting worse, in the South East at least, so that's obviously not working!
My point double-made!
Erm how does me disagreeing with you make you right?
Sorry, I just don't see how bigger gaps in cities would improve traffic flow. Folk go from green light to red light at constant speeds.
By and large, big road programmes are no longer justified at all
not big but £11m pounds to change a couple of junctions/provide some bus lanes on A61 in to Sheffield will reduce journey times at peak times by 3 minutes over 4 miles
no improvements for pedestrians (except narrower pavements due to bus lanes) and cyclists will be able to share the bus lanes - a useful breather since proposal also includes increasing speed limit on the narrow lane dual carriageway
the proposal says that a future park n ride would find the bus lanes would help encourage switching but the site and costing for the park n ride isn't in the proposal
lots of words about change but no action
My take on this is that schools (at secondary level) should teach the Highway Code, road awareness, etc., leading to sitting the Theory part of the Driving Test at the end of the course.
That way pedestrians and cyclists at least have an opportunity to familiarise themselves with the ways of the road even if they haven't taken a driving test.
If you know you are going to encounter a red light why drive so close? You are merely in a rush to join the queue.
You made my point because my point was that most drivers are so oblivious to bad driving that they do it all the time, never understanding.
When you drive too close to the car in front you relinquish control to the driver in front - he brakes and you have no choice but to do the same. He also masks the road ahead so you drive by his eyes.
I hear what you are saying glenp, just because I disagree does not make me wrong.
My point is that if all drivers are closer together then more cars get through before the red light. You can't see past the driver who is 2s ahead either - and the bigger gap allows more stuff to happen in it.
All applying only to congested city driving of course, and I'm saying I'm right per se, I just don't see that you are (in those narrow circumstances).
12-23M at 20-30mph - fair enough, not generally complied with I'd say.
As 30 mph is around 13 m/s so 23 m gap is almost two seconds! 12 m at 20 mph is 1 1/2 seconds. Try counting the time gaps or looking at the distance.
The bigger gaps and slower top speed giving higher average speeds is well proven - its by reducing bunching up. Cars speed up and slow down less so average speeds are higher - not always and not always significant but its a well known phenomonon on congested roads - no nmatter the speed limit
I think to a degree you are arguing against something that you haven't tried. I'm not talking about crawling inner city traffic, but actually 2 seconds is still is reasonable gap under any circumstances.
Here's an example that actually happened to a friend of mine who does drive too close (and cycles, so he really should see sense, but can't for some reason). He was following a car along an A road at night and the car in front swerved unexpectedly to avoid a cyclist. So my friend then is also swerving on his reactions to avoid the same. Luckily nothing was coming the other way so all was well, but all my mate could say to me was that the cyclist was not visible enough, not admitting that if he'd been a few seconds further back down the road not only would he have had much more time to deal with it but probably would have seen the bike for himself.
I reckon a number of seconds gap is not really a practical way of putting it, because you do (I admit) kind of get drawn into moving queues sometimes. Better to just make your priority number one to maximise the space around your vehicle. If you haven't tried it for a few months you just won't realise how much better it is. If you do try it and get used to it you will never go back.
glenp - your example is on an A-road.
Cars speed up and slow down less so average speeds are higher - not always and not always significant but its a well known phenomonon on congested roads - no nmatter the speed limit
Even for a short stretch between traffic lights?
Can both of you wake up to the fact that that's what I'm talking about?
Al You are right of course. Everyone else is wrong as is all the research.
Please show me the research that relates to the situation I have been discussing (rather than yours).
Yes, even for the short stretch between lights - if you go with the flow and don't rush you may even get the "green wave" effect.
Well, we've gone off topic really. The point was that bad driving goes unnoticed, whereas bad cycling gets the opposite sort of attention - ie people remember instances of bad cycling because it confirms the bias that is constantly reinforced in the media and elsewhere.
For heavy urban areas, town high streets etc, I would like 20mph limits - then you just roll along gently rather than racing to the next red light.
IMO there is no solution to this via legislation; applying the same rules to bicycles that are enforced on cars just doesn't work.
I commute daily through Cambridge, a city with a quite a few cyclists and a larger number of idiots on bicycles. I generalize somewhat but the "cyclists" are in hi-viz jackets, stop at red lights and have a bike with working brakes and lights; the others don't and it really winds up the motorists. Since the average motorist cannot distinguish between the two groups on bikes they decides we're all as bad as each other. So I've been the brunt of motorist's frustrations on a handful of occasions without any provocation on my behalf. C'est a vie.
But here is the rub. On a bike in this city I feel significantly more at danger from other people on bikes than I do with cars. Sure the cars have the potential to inflict greater injury, but they are generally stationary in traffic or moving in a predictable manner.
Then there is summer with the massive increase in hire bikes. Lethal. How does the training and licensing solve this problem? It doesn't. Yellow sticker on the down tube = accident imminent.
I've had far more close calls with motor vehicles than people on bikes in Cambridge.
I am generally passing other rides so I can assume they're idiots and give them a wide berth.
I regularly have vans and buses half overtake and then try to squeeze me off the road when something comes the other way. Its less frequent with cars as they can normally fit into the bits of road they want to occupy.
In addition to safety, there are other potential benefits to be gained by speed limit reductions in
urban areas. Those suggested in the literature include an increase in traffic flow and consequent
reduction in congestion and delays, particularly where the roads are functioning at near capacity.
Further, reductions in speed bring about a reduction in vehicle operating costs with less wear and
greater energy (fuel) efficiency, and less pollution and noise (see e.g. Carlsson, 1997; Kallberg and
Toivanen, 1998; Cameron, 2000; Elvik and Vaa, 2004).
You can follow the references from here if you want to
Then there is summer with the massive increase in hire bikes. Lethal
how many are routinely killed in this way every year in Cambridge ?
TandemJeremy - Member
In addition to safety, there are other potential benefits to be gained by speed limit reductions in
urban areas. Those suggested in the literature include an increase in traffic flow and consequent
reduction in congestion and delays, particularly where the roads are functioning at near capacity.
Further, reductions in speed bring about a reduction in vehicle operating costs with less wear and
greater energy (fuel) efficiency, and less pollution and noise (see e.g. Carlsson, 1997; Kallberg and
Toivanen, 1998; Cameron, 2000; Elvik and Vaa, 2004).
Cheers I'll try and get a read of that - interesting qualifier underlined as above - I recall this was how you qualified the £500 death-trap argument?
Its just the first referenced stuff I could find on this - hoever if you follow the citations and references you should be able to find more.
Its morre obvious on congested motorways but the same effects work on congested urban roads.
Its one of those things that really irriate me - 20 mph limits on urban streets will have little overall effect on total journey times, decrease polution and make cycling safer as well as reducing pedsetrian casualties - but because it goes against the "common sense" of the road lobby it will never happen
Here's my tuppence worth:
I filled in the survey. I said there should be more police making cyclists obey the law (because I don't see why cyclists should deliberately jump red lights). I said there should not be cycle licensing. I said that drivers should be trained on judging the speed of a bike and should learn the Highway Code on entering cycle lanes and overtaking cyclists.
Here's a couple of observations (I commute in London btw and have done since 1987 - with a 10 year break - when I commuted in rural N Northumberland and then from Gala to Edinburgh)
I was on a bus one day and a group of girls were talking, one complained "I've taken my driving test four times and still haven't passed" - the others empathised. They did not seem to understand that driving is a skill and a driving licence must be earned, and is not awarded as of right. She did not countenance the possibility that she might simply have been a rubbish driver.
People take the same kind of liberties when I am in my car (a MASSIVE 4x4) as they do when I'm on my bike. My conclusion? People generally don't think, don't give a sh1t, have somehow abdicated responsibility for their actions.
Thing is, when I'm in my car; they will lose, when I'm on my bike, they may very well win.
2 seconds? I wish! If you leave more than a gnat's c0ck, someone will pull into the gap.
And don't get me started on the idiots who pull into my braking space when I am towing my caravan.
Its one of those things that really irriate me - 20 mph limits on urban streets will have little overall effect on total journey times, decrease polution
I said there should be more police making cyclists obey the law (because I don't see why cyclists should deliberately jump red lights).
I agree with your point about people thinking there is some sort of right to drive. Personally I reckon that having failed 4 times suggests there's something basic you're not getting, so maybe you should have to wait a year or two before trying again (as to people who've failed tens of times - they should probably never be allowed to drive simply because they freakishly managed to be competent for half an hour at some future point, before inevitably reverting to being rubbish). I'm sure I'll be accused of being very right wing for comments like that! Not that the skills to pass a test are necessarily that much of a challenge to young men (and boys) who'll then be irresponsible on the roads - I should know, I passed first time at 17 
aracer - yes, I take your point re the police.
I am a motorist and a cyclist. In my car I am tagged via my numberplate, on my bike I am anonymous.
The thing about cyclists jumping red lights is this, I don't jump red lights so I am next to the cars and I can see the fury in motorists' eyes. Motorists already feel hard done by and feel they have bought some kind of right to be on the road. Cyclists are seen to be getting off lightly - tax wise - yes I know roads are funded from general taxation (not solely road fund licence), but you know what I mean.
As for numbers of times taking the test. I worked for a Greek solicitor whose elderly Greek mother had tried and failed her test in this country many many times. The Greek solicitor was proposing to send her mother home to Greece to take her test there, where it is easier, and her licence would then be valid here. How scary is that?
aracer - MemberI presume you'll point out that it would only take me 2 minutes more for the 2 miles of 30 limit I can usually do a steady 30 in? The fact my car (and most others) uses less fuel and generates less pollution at 30 than at 20 is undeniable though.
Rubbish and piffle as I showed last time. To accelerate to 20 mph takes less energy than to accelerate to 30 mph/
In congested streets journey times would not increase as is proven. Also it reduces pedestrian and cylist casualities. Streets are for all not just cars.
In a steady state the RAC managed to show a slight and insignificant increase -= even they admitted in stop start conditions less petrol and less pollution occur in a 20 mph limit.
I proved this to you last time we had this debate.
Edit - I would also give you more 40 limits if I ruled the world - congested urban with shops houses and cyclists - 20 mph. Open suburban where pedestrians cycles can be separated and right and left filter lanes possible - 40 mph.
The fact my car (and most others) uses less fuel and generates less pollution at 30 than at 20 is undeniable though
but if 20mph urban speed limits become the norm then car mnfrs (hopefully) will change the engine management systems / gearing to match this - wouldn't have thought a big deal - of course depends on buyer perception of the importance - one of my pet hates is that pedestrian safety ratings get little mention in car reviews
Why not make everyone applying for a provisional license take a formal cycling proficency test and pass it and under take several months of cycling prior to being let loose on the roads in a car? That way they would appreciate other road users and also develop an understanding of road craft from another users point of view.
May make them a bit fitter too....
Also it would increase the numbers of cycles on the road - safety in numbers and all that.
myheadsashed - Member
Why not make everyone applying for a provisional license take a formal cycling proficency test and pass it and under take several months of cycling prior to being let loose on the roads in a car?
Makes sense in theory, but you can bet that there would be a way round it, an opt-out for those who couldn't cycle for whatever reason, and everybody would manage to get that opt-out.
Don't forget that to pass your test in this country it's not compulsory to drive on a motor way, in bad weather, on a countryside road lined with dry stone walls, etc, etc, etc. You can be a fantastic driver around your local area, on dry summer evenings, but that means nothing when you are driving across Dartmoor in a monsoon a few days later.
Even the simple fact that the Theory Test is based on a percentage scares me - how can you be allowed on the roads if you don't recognise some roadsigns in your test?
Wow. Gone from "potential" to "proven"?
Rubbish and piffle as I showed last time. To accelerate to 20 mph takes less energy than to accelerate to 30 mph
In congested streets journey times would not increase as is proven.
but if 20mph urban speed limits become the norm then car mnfrs (hopefully) will change the engine management systems / gearing to match this - wouldn't have thought a big deal
Oh I do love an argument ....now that bit is correct
not sure if totally relying on future technology - plenty of small city cars around and more appearing all the time not big breakthrough in technology just a focus on matching engine output to need rather than performance - the trend already exists
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