I shouldn't be surprised if all the energy wasted in accelerating up to 30mphish only to hit the breaks to go back down to 0mph at the next set of lights exceeded any extra fuel used because drivers stayed in a lower gear to keep below 20mph.
CityCyclingEdinburgh Forum » General Edinburgh
"20mph limit to go ahead across Edinburgh"
(230 posts)-
Posted 10 years ago #
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There are quite a few articles on this - I did a search on "fuel consumption at 20mph", and the general conclusion is that if the speed is steady, and not accelerate/brake, then pollution comes down, so the techniques for encouraging these limits have to be considered.
On Harrison Road in the mornings, I see folk "leap frogging" from one hump to the next - this will use fuel fast, whereas if they drove at a constant speed of ~20 they could go over the humps without braking, and use far less fuel.
Obviously, they could get bikes, and go round them (or if you're me, go over as fast as possible, often with a "Wheeee" as I do), but that's a different subject.
Posted 10 years ago # -
A bit of a discussion of the fuel consumption question here along with links to a couple of studies:
http://www.theguardian.com/environment/2010/apr/19/ask-leo-20mph-speed-limits-pollution
Posted 10 years ago # -
I see folk "leap frogging" from one hump to the next - this will use fuel fast, whereas if they drove at a constant speed of ~20 they could go over the humps without braking, and use far less fuel.
This is what happens on streets like Montgomery Street, McDonald Road, Brunswick Road, etc. My theory is that too many drivers watch Top Gear and think they have to floor it at any given opportunity, no matter how fleeting.
I do hope Easter Road will be included in the 20mph zone. What about London Road? Arguably many sections of London Road/Portobello Road are residential, ie. Abbeyhill, Jock's Lodge, etc. 20mph for these? Or not, because they are 'arterial routes'?
Posted 10 years ago # -
Has anyone ever tried driving at 20mph in a 30mph zone? What happened?
Posted 10 years ago # -
I have given up driving at 30mph in 4th gear awhile ago, I now always drive in 3rd in 30 limits. My car simply doesn't like it anyway if you genuinely stick to below 30 in 4th. (32 - 35 seems to work OK in 4th, but that's not 'acceptable' any more).
My default driving speed is now 25 in a 30, I only go up to 30 if the road is really clear of potential hazards. I don't care if I'm 'holding up' anyone. Most times I get to the next red light just behind the next car who was going at 30 anyway.
The other night I drove through Holyrood Pk at 20 (in the 20 section) and I had a cabbie driving 2 feet off my tail down the centre line, trying to overtake as we were approaching the zebra...
Posted 10 years ago # -
@fimm I fairly regularly drive around 20 to 25ish and just like Ed I just arrive at the next red light or queue that I would have arrived at anyway. Usually the only noticeable effect is that people sit very close behind you enraged at being prevented from admiring the red light earlier. It's a very similar feeling to being a cyclist.... strangely enough.
Posted 10 years ago # -
"@edd1e_h The other night I drove through Holyrood Pk at 20"
So that was you. It's very unusual seeing people obeying the speed limit round Holyrood. I've counted 3 in 390 commutes.Posted 10 years ago # -
I tend to drive at around 25, unless I'm in a rush. I take great pleasure in driving at "only" 20mph in the relevant limits (but I never need to drive through the park).
It's quite interesting if you back off a bit how few following drivers actually do crazy stuff. There are some, naturally, but then I often get overtaken (in the car) doing "only" 30mph on the Lanark road up towards Balerno.
Posted 10 years ago # -
From the front-lines of driving at the speed limit and no more (aka being a learner driver):
Holyrood Park - Get overtaken all the time, often get blasts of the horn
London Road - Been undertaken while traveling at 30
Willowbrae Rd - Undertaken coming down the hillEvery lesson, without fail.
Posted 10 years ago # -
"often get blasts of the horn"
Even when you've got L plates up? Sheesh.
Holyrood Park has to be the 'hardest' road to maintain 20 due to the pressure from behind.
Like Dave I quite enjoy getting to drive through 20mph zones and actually hope that there will be someone behind me.
Posted 10 years ago # -
"Borken society" when people get annoyed when you follow the rule of law.
Posted 10 years ago # -
"Borken society"
Or when everyone develops a cod Swedish accent and spends all their time trying to roast reluctant chickens. :-)
Posted 10 years ago # -
"Holyrood Park has to be the 'hardest' road to maintain 20 due to the pressure from behind"
Indeed.
I must confess that I always keep an eye out for eejits revving up behind when I drive that stretch - and have <embarrassed cough> been known to increase my speed if anyone is foolish enough to start an overtake maneouvere.
Childish, I know, but watching the silent ranting and hand signals in the mirror is just devillish fun.
Posted 10 years ago # -
Not that I'm saying people should give in to the pressure to speed up, but deliberately annoying someone who is in charge of a couple of tonnes of metal might not necessarily be appreciated by the next person they come across on the road... I'd rather people weren't angry behind the wheel, and I'll not look with any relish on being in a position where I might be raising someone's ire.
But like I say, if you're sticking to the rules (as we should be) it's hard to see what else to do. I guess it's just the pleasure in seeing someone's blood pressure rise that worries me.
Posted 10 years ago # -
@WC. Angry people are angry people. If they don't get angry about someone doing 20 in front of them, they'll get angry about something else (e.g. maybe they'll shout abuse at the poor granny slowly crossing the zebra instead)
It's angriness all the way to the top (or bottom)
Posted 10 years ago # -
"If they don't get angry about someone doing 20 in front of them, they'll get angry about something else"
So might as well make them angry now? I have been accused in the past of being too polite, but I reckon some common courtesy can go a long way (and falling into the 'but they're not showing me any common courtesy' trap of treating all drivers as if they're the same is very like the old 'cyclists don't deserve respect until they can all obey the rules').
Maybe it's just me that assumes people aren't angry all the time and is willing to give people the benefit of the doubt - I'm glad cynicism hasn't quite battered me down that much yet. Do unto others.... (one of the few Christian mantras I actually respect and follow).
Posted 10 years ago # -
Overtaking someone who is sticking to the speed limit, especially in an urban street, does that not suggest to you that they are already angry?
Posted 10 years ago # -
Angry/stupid/borken
Posted 10 years ago # -
"... does that not suggest to you that they are already angry?"
Could it equally be impatient? Risk taking? Negligent? Stupid? So no, it doesn't necessarily to me suggest that they are 'angry'. In fact I'd say the majority of people overtaking over any speed limit aren't doing it because they're angry...
Posted 10 years ago # -
Apparently, this is Borken, "a town and the capital of the district, in North Rhine-Westphalia, Germany. Population: 41,245. Situated 10 km east of the Dutch border. "
Note the bloke on a bike.
Posted 10 years ago # -
In my limited experience stupidity and carelessness outnumbers angry, though many drivers are quick to anger if they think they are being delayed.
I had an idiot in a middle of the range saloon dangerously close to my back wheel one morning when coming along Lanark road at "only" 30mph. Once he got *really* close I slowed to about 25mph simply to reduce the risk if he hit me. This was followed by a ludicrous attempt to overtake on the approach to Gillespie crossroads, where guess what, he was turning left!! All this while I was sat on a bike which is potentially very, very fast... Certainly waaay faster than the car!Posted 10 years ago # -
Could it equally be impatient? Risk taking? Negligent? Stupid?
None of which are any better encounter whilst on the bike. All of which are usually made angry by either having their way impeded by a slower road user (or a red light) might as well try to keep them behind you and their speed controlled when in the car.
Posted 10 years ago # -
Clearly I look at this differently from everyone else on the thread.
Posted 10 years ago # -
I have read many of the comments, and judging by them we'd better be ready for more flooding in Edinburgh... from the amount of froth coming out of their mouths!!!
I genuinely worry for the safety of all of us if we were ever to find ourselves sharing the same stretch of the road as the idiot who uses the "Fuelhead" moniker.* His constant comments about "driving to the conditions, not the speed limit" (always in excess of the limit)and claiming to ignore the limits suggest he's a very dangerous person to be allowed behind the wheel. Even if he's all mouth and no trousers, he still exhibits qualities of someone who could use some psychiatric evaluation. Ten again, that last statement could go for most of the EEN brigade.
*(Fuelhead says, in reply to: "If a child suddenly steps in front of you, you are much less likely to seriously injure or kill them if you keep to a 20Mph limit!"
"I'm not likely to be caught out by that and neither is any driver who is alert. In any case, once again, you are bringing this down to basic physics and that is not a valid argument." Scary that anyone happily claims to be that naive.
Posted 10 years ago # -
All of these drivers with such astonishing driving skills - it's amazing that there are any incidents at all on the road.
Even assuming "Fuelhead" has the reaction times and skills of a F1 driver, he* still has to deal with all of the "ordinary" drivers making errors, misjudgements, unanticipated manoeuvres....
*I am assuming its a bloke.
Posted 10 years ago # -
"Damn you with your basic physics"
Posted 10 years ago # -
@WC - I take the point about angering drivers, although I'm the one with the hot temper when threatened with becoming a KSI stat.
When I started cycling, I left gaps that could be exploited by skilled, considerate drivers - pulling in to a secondary position to allow "in lane" overtaking, using the cycle lane at pinch points, etc.
Unfortunately I've been repeatedly scared by drivers taking advantage of my courtesy - I'm afraid that every scare means that overtaking is increasingly only possible where it can be done safely even by the most inconsiderate cack-handed oaf.
Yes, that isn't playing fair since most drivers aren't inconsiderate cack-handed oafs, but the thing is, I don't know what sort of driver is currently waiting to overtake...
Robert
Posted 10 years ago # -
My father once ran into a boy running across the road when we were visiting my grandparents in Stonehaven as a child. I would have challenged anyone to have missed him or stopped in time. He ran out in front of us from a side street (or garden, I forget which now) and my father (who was travelling under the speed limit) thankfully stopped quickly enough that the boy received only relatively minor injuries.
I have my doubts the boy would have lived had the likes of "Fuelhead" been behind the wheel...
Posted 10 years ago # -
@ Roibeard
I wish I could say i think your post is a load of nonsense. Sadly, I can't.
I try to make a point of making it awkward for someone to pass me if I judge it unsafe or unwise for them to do so. That does not mean I deliberately inconvenience drivers at any opportunity - heck, I'd rather have them miles in front of me that inches behind!! But if I perceive an risk to myself, behind is where they'll stay till I can let them race ahead.
I used to wave cars out of junctions a lot but I find myself doing it less frequently now, simply due to the lack of gratitude the majority of motorists show, despite the fact you're saving them the "hassle" of trying to pass you on the road. I still do it, but I pick and choose when more selectively.
I still wave approaching buses through narrow gaps (if there's no traffic too close behind me) in the hope it fosters better relations with their drivers, and in the knowledge that (despite even Lothian's drivers lapsing back into ASL abuse etc), they tend to be more likely to acknowledge what you did for them.
Posted 10 years ago #
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