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Our local council recently changed the 30MPH limit in our village to 20MPH. Entering the village now on a single-carriageway road you go directly from the national 60MPH to the new local 20MPH - a change of 40MPH. But I though that highway regulations forbade a drop of more than 30MPH in one go? Have the rules changed? Is this situation legal?
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I'm not aware of any restriction in speed limit changes - although many authorities put a in-between limit for a short distance to slow traffic down more gradually.
Edited by RT on 06/12/2013 at 12:00
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Is a 20mph limit enforcable in the UK I wonder how the powers that be check or enforce this limit.
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It's certainly enforceable, by fixed camera, mobile camera or hand-held device - however the police aren't likely do allocate much resource to this - many of the 20mph limits are "self-enforcing" in that they're in places where it's difficult to do more than 20mph.
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Indeed our local police have already stated in the local media that they do not intend to enforce the limit - but I don't take that as an excuse to relax!
Part of the limit is on a long steep hill - to get up it now within the limit is a long slow grind in 2nd (or 3rd if you're lucky) gear (otherwise you stall), whilst coming down you need to ride on the brakes most of the way just to get below about 25MPH. I dread to think what this will do to cars, fuel consumption and pollution.
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There is no law which says you can't drive a car in second gear. Match the gear for the speed required.
If you need second, or even first, to prevent being on the brakes whilst descending a steep hill use it, you aren't using any fuel by doing so, so no pollution issues.
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There is no law which says you can't drive a car in second gear. Match the gear for the speed required. If you need second, or even first, to prevent being on the brakes whilst descending a steep hill use it, you aren't using any fuel by doing so, so no pollution issues.
Unfortunately driving instructors nowadays teach students "gears to go, brakes to slow" and as a result sensible use of lower gears to descend hills doesn't seem to occur to anyone but those who learnt when drum brake fade was a possibility. Yes, I know brake pads and discs are cheaper to replace than gearboxes, but I'm not going to cruise downhill with a foot on the pedal.
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Fifty years ago I was told, as a rule of thumb, one should go down a hill in the same one would use to go up it
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Would it be possible to fit retarders to cars like they have in larger commercial vehicles? Would make long descents eaiser on the brakes and gear box.
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Certainly possible, but adds cost and probably needs more space? I presume you refer to regenerative braking?
Engine braking, plus disc braking on the steepest hills is adequate for most cars.
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but I'm not going to cruise downhill with a foot on the pedal.
Out of curiosity, why?
You usually would have a foot on a pedal to go up the hill.
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but I'm not going to cruise downhill with a foot on the pedal.
Out of curiosity, why?
You usually would have a foot on a pedal to go up the hill
Accelerator pedals are intended to be comfortable to press for long periods without effort,brakes are not. Also, hitting a patch of ice or oil with brakes on could make the car more unstable than using engine braking. Feel free to rely on your brakes, if you prefer.
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Also, hitting a patch of ice or oil with brakes on could make the car more unstable than using engine braking.
Other way round surely - the brakes would be operating on all 4 wheels, engine braking only on 2 - even on most 4wd they'll be transmitting no torque to the rear when engine braking.
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Other way round surely - the brakes would be operating on all 4 wheels, engine braking only on 2 - even on most 4wd they'll be transmitting no torque to the rear when engine braking.
I thnk Galileo's point was that you might get a spontaneous lock up under braking. ABS would probably sort it out but not without ans alarum for the driver.
First half mile from here to nearest town isn't usually gritted. Includes a short sharp descent that coincides with a pinch point created by nearside side parking. Car is much easier to control using just the accelerator and low gear. Brakes only in play if there is a need to stop for traffic coming other way through pinchpoint and then only to lose last few mph.
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I thnk Galileo's point was that you might get a spontaneous lock up under braking. ABS would probably sort it out but not without ans alarum for the driver.
Under engine braking, the 2 driven wheels will be applying roughly double the retardation force per wheel as 4 wheels being braked - so the 2 wheels being engine-braked are more likely to lose grip in slippery conditions - and as the 2 undriven wheels are more likely not to lose grip it becomes a very unstable pirouette !!
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I thnk Galileo's point was that you might get a spontaneous lock up under braking. ABS would probably sort it out but not without ans alarum for the driver.
Under engine braking, the 2 driven wheels will be applying roughly double the retardation force per wheel as 4 wheels being braked - so the 2 wheels being engine-braked are more likely to lose grip in slippery conditions - and as the 2 undriven wheels are more likely not to lose grip it becomes a very unstable pirouette !!
Not if it is front wheel drive, locked fronts slide, rears roll, stays straight.
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Load sensitive braking will also be in play. With only a driver on board rear brakes will not be doing much work.
My car, diesel Berlingo, definitely feels safer on slippy roads driven with gentle throttle and minimal use of foot brake. So did my Xantia.
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Back to the originall question! Can a 60 mph limit be reduced to 20 mph in one stage by one roadside sign?
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What happens with a front drive car under engine braking when one wheel loses grip? The assumption here is that both lose grip simultaneously. At least using the brakes you have the back up of ABS acting on each wheel, on most cars. What is the back up using engine braking?
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What happens with a front drive car under engine braking when one wheel loses grip? The assumption here is that both lose grip simultaneously. At least using the brakes you have the back up of ABS acting on each wheel, on most cars. What is the back up using engine braking?
One can of course use the brakes if necessary, equally my car and many others have an ESP program which works in conjunction with the ABS system. I never said I don't use brakes, my point is that when a lower gear controls descents I use it rather than riding the brake pedal for long periods.
Have you ever driven the A 6024 over Holme Moss? Try that in top gear, using brakes only.
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Can a limit go from 60 to 20? From my reading of the regs, Yes.
Interim limits can be used, say 60, 40, 20, but they should only be used where an immediate drop from 60 to 20 is deemed unsafe. So if you can see the 20 sign for a good distance from the 60 zone no need for an intermediate speed.
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