In fact, I'm a road that - sort of - has a 20mph limit.
It's quite simple, are there circular signs with red edging around a "20". If there are it is 20 (compulsory and enforceable) if there are not, then it is not. There can be no "sort of"
In fact, I'm a road that - sort of - has a 20mph limit.
While you can have different speed limits in two directions, as far as I am aware the carriageways must be separated. I think it required a specific change in law to work, and as such only works on dual carriageways. There's only two roads I can think of, and one of these is the A10 between Waltham Cross and Cheshunt (College Road). 40mph one way, 70mph the other. It always used to be 70 in both directions.
How can you enforce a limit where the same road has two different speeds depending on which road you used to enter? And if you park up, then leave the next morning, which limit is it then? Still the one from the last entry point? And if you always come in from the other end where it's 30mph, can you be done?
I think you'll find there has to be a traffic order and whatever else is required to impose a different limit beyond the normal 30mph in town. Otherwise any local resident could get a sign made up and place it on a post, then expect people to be prosecuted.
Once in a 20mph, there are not always repeaters to remind drivers that the limit isn't 30mph, so are drivers expected to remember that the area has the lower limit?
AM9 - you are thinking of a 20mph Zone, which is a variation on a theme, in that the speeds are self regulated by traffic calming features - no part of a zone should be more than 50m from a calming feature and a cul-de-sac should be no longer than 80m from a feature - rules have been relaxed recently on what constitutes a traffic calming feature. Typically hump frequencies in a 20mph Zone range between 60-80m apart to regulate speeds at about 24-26mph
Variable speed limits would make more sense. During rush hour, school hours or whatever, it's 20mph. At other times, it's 30mph. Either with signs that state times or, better still, electronic signs that change.
On major roads, not side roads or residential estates.
Variable speed limits would make more sense. During rush hour, school hours or whatever, it's 20mph. At other times, it's 30mph. Either with signs that state times or, better still, electronic signs that change.
Motorways seem to do well with variable limits, so it's really just the cost that is likely holding back a wider roll out. I assume there's also the issue of what happens if digital signs fail. There clearly needs to be a 'fail safe' and how would that work? Everyone knows that you revert back to nn mph if there's no sign displayed?
What would a court do with such a case where an injury or damage occurred?
So, without a visible sign or real traffic calming measures, a driver starting their journey within the area would assume that the limit is 30mph. The ACPO recommendations for prosecuting speeding gives 2mph + 10% leeway for all speed limits above 30mph, but specifically mentions 20mph as an absolute maximum with no allowance for driver/car measurement uncertainty.
What would a court do with such a case where an injury or damage occurred?
I'm unsure which ACPO guidelines you're quoting from. What I believe to be the current version dated 14th October 2013 and valid through to review in May 2015 certainly quotes the 2 mph speed device tolerance at 20 mph and indicates that a speed of 24 to 31 mph would be appropriate for the offender to be offered a place on a speed awareness course - over 35 mph would result in prosecution with points/possible disqualification if found guilty. 24 mph is, in effect, 20 mph plus 2 mph plus 10%. The document was written by Suzette Davenport, Chief Constable lead on traffic policing.
It has a blanket 50mph limit until your beyond Stockton. During the rush hour it's neccessary because of the volume of traffic trying to join and leave at various junctions. But otherwise during the day and overnight it could easily be 70mph with no real impact on safety.
I've been scouring the internet for something definitive, unambiguous and, most of all, correct, but it's pretty hard to find. The best I can find is from ACPO (the Association of Chief Police Officers) which states 20 mph limits are legally enforceable then goes on to indicate that, in normal circumstances, the police have better uses of their time than to do this! There is a hint, too, that a 20mph limit that is not part of a 20mph zone might just attract more police attention, but you do have to read between the lines somewhat.
Many people are taking no notice of the 20 zones. I also don't think that 20mph zones make for cleaner air as vehicles have to drive in lower gear.
And?I also don't think that 20mph zones make for cleaner air as vehicles have to drive in lower gear
And?
If you apply a 20mph speed ceiling then people aren't accelerating hard out of junctions so vehicles are using less energy therefore they consequently must burn less fuel & emit less fumes.
kinetic energy = 0.5 x mass x velocity ^2
Surely the main point about 20 mph limit as opposed to 30 mph is that average speeds will decrease from about 35 to about 25 mph, so the objective is largely achieved. The person doing 50 will,however, not go any slower.
you got a fuel efficiency chart for a modern car that shows that?
If you are interested in obeying the speed limit, then you will have to observe your speedometer frequently whether the speed limit is 30 mph or 20 mph.
I find it quite disturbing that even motoring organisations pedal the myth that checking your speedometer is dangerous. Anyone who has had driving lessons from a reputable instructor will know that you have to keep your eyes moving constantly, so you would be glancing at your speedometer as a matter of course.
In a lower gear, there is often more sound energy etc. produced - fuel efficiency charts show that the optimum speed is about 30mph.
Robertj21a:2140070 said:Most drivers know very well what speed they are doing without regularly checking the speedo.
Really ? - can you provide a link please