tonyishuk Posted August 30, 2013 Share Posted August 30, 2013 It is the inconsistency between areas that annoys me (as the Post Code lottery in the NHS). We are a very small island, gone are the days when communications between authorities took weeks to complete. In West Sussex ], I feel we are well served by the local authority who paint changes of speed limits on the road and advertise the speed limit of the speed camera before the camera. AND Motorists STILL GET TICKETS ???? Must be thick as planks. Other area of the UK, cameras and signs are hidden either intentionally or otherwise by bad maintenance of the roadside growth. I agree with views offered by others about the 30 >> 40 >> 50 >> 30 mph limits varying on seemingly a road where there is no visible change of why the limits change. In conclusion, anyone know how often speed limits are updated on Sat Nav's ? A road local to me has a changed limit for over two years, which I have updated by Tomtom Share, but I have to change the limit every time I update the map. Rgds Link to comment Share on other sites More sharing options...
Mrs T Posted August 30, 2013 Share Posted August 30, 2013 If everyone drove according to the limit signs then councils would not waste time and money in erecting them. The answer is in the hands of the motorist. Link to comment Share on other sites More sharing options...
bolero boy Posted August 30, 2013 Share Posted August 30, 2013 I used to drive from Street to Enmore, nr Bridgwater and the speed limit changed over 20times!! Not one single yard of my journey incorporated 'the National Speed Limit' of 60mph on a single carriage way. Every bit of what used to be described as 'open road' is now restricted in some way. Very soon the Highway Code's Narional Speed Limit will be 50mph as this appears to be the applied limit to very many major roads these days. Link to comment Share on other sites More sharing options...
teflon2 Posted August 30, 2013 Share Posted August 30, 2013 Mrs T - 2013-08-30 6:59 PM If everyone drove according to the limit signs then councils would not waste time and money in erecting them. The answer is in the hands of the motorist. If they didn't erect the signs we wouldn't know what the limit was. John Link to comment Share on other sites More sharing options...
Dave Newell Posted August 30, 2013 Share Posted August 30, 2013 Peter James - 2013-08-30 10:08 AM Dave Newell - 2013-05-09 7:21 AM Well yes, a vehicle with ABS willstop in less distance than one without if the wheels are locked but a good driver should be able to brake hard without locking wheels up and in this case the stopping distance should be shorter than the ABS equipped vehicle. If you hit the brake pedal so hard that you lock one or more wheels then you should quickly release and reapply the brake but not quite as hard. D. That assumes the brakes are well balanced front to rear and side to side. Which is unlikely without ABS. Interesting as it is that this thread has been ressurrected by none other than a foreign internet troll I do also find your comment to be fallacious and inaccurate. ABS does not balance the brakes, neither front to rear or side to side. Fact is at the annual MOT (and I fully accept that a lot can happen in between tests) brake balance is checked and if found to be outside of acceptable levels will result in a failure. What ABS does (and this can vary according to the vehicle's specification) is to cut braking pressure in the event of any single wheel locking. On more advaned systems it can cut the braking pressure to the locked wheel alone. In the first instance all braking is cut to let the locked wheel start turning again then braking effort is re-applied to the whole system. In the second instance the braking effort canbe cut to the psecific wheel that has locked allowing that wheel to start turning again but in the meantime maintaining braking effort on all other none locked wheels. A locked and therefore skidding wheel offers much less resistance to travel than a wheel which is still turning but applying braking effort. This is the ONLY reason ABS can offer shorter stopping distances. D. Link to comment Share on other sites More sharing options...
Guest Peter James Posted August 31, 2013 Share Posted August 31, 2013 Dave Newell (foreign internet troll ) - 2013-08-30 10:07 PM ABS does not balance the brakes, neither front to rear or side to side...... On more advaned systems it can cut the braking pressure to the locked wheel alone. Well that is effectively balancing the brakes isn't it? Link to comment Share on other sites More sharing options...
Dave Newell Posted August 31, 2013 Share Posted August 31, 2013 Peter James - 2013-08-31 12:07 AM Dave Newell (foreign internet troll ) - 2013-08-30 10:07 PM ABS does not balance the brakes, neither front to rear or side to side...... On more advaned systems it can cut the braking pressure to the locked wheel alone. Well that is effectively balancing the brakes isn't it? Most definitely not. D. Link to comment Share on other sites More sharing options...
Dave Newell Posted August 31, 2013 Share Posted August 31, 2013 Peter James - 2013-08-31 12:07 AM Dave Newell (foreign internet troll ) - 2013-08-30 10:07 PM ABS does not balance the brakes, neither front to rear or side to side...... On more advaned systems it can cut the braking pressure to the locked wheel alone. Well that is effectively balancing the brakes isn't it? My apologies for the brevity of my previous reply, I didn't have time to explain properly this morning. ABS (Antilock Braking System) does exactly what it says on the tin i.e. in the event of wheel loockup under hard braking it will release the brakes to correct the locked and skidding wheel. A locked and skidding wheel has a much lower coefficient of friction than a wheel which is still revolving but subject to braking effort plus it is not steerable once locked. Maximum braking efficiency occurs fractionly before a wheel locks. A brake imbalance is when the two wheels on the same axle give differing levels of braking for the same pedal pressure, this can be caused by a variety of factors but the most common ones are rust build up in the mechanism of the wheels brakes, whether they be disc/pad or drum/shoe. In the case of imbalance the ABS system cannot correct the imbalance, for one thing the ABS will not be activated until the pedal is pressed hard enough to lock one or more wheel(s) therefore the ABS does nothing to correct the brakes' imbalance issue. Early ABS systems would cut braking effort to the entire system in the event of a lockup, all wheels would be released before the ABS system would re-apply braking pressure, it was quite common to feel the brake pedal "pulsing" during ABS operation. More advanced ABS systems are capable of releasing the brakes only on the locked wheel and re-applying braking effort so quickly as to not inadvertently cause an imbalance (if the wheels on an axle have high braking effort applied and one wheel locks and is then released by the ABS there would be a serious imbalance across that axle albeit for a brief period of time, modern ABS systems are so fast that the imbalance is present for an insignificant moment of time. The two major purposes of ABS are to A) maintain braking effort during emergency braking periods by modulating the applied pressure to the wheels braking systems and B) to maintain steering during the same emergency braking periods by not allowing the wheels to remain locked and therefore in a skidding situation. What ABS has done is to remove the onus from the driver to brake effectively during an emergency. Some drivers, myself included, were taught "cadence braking" which is very similar to what ABS systems do but controlled by the driver, the idea is you hit the brake pedal hard and the moment you feel a wheel lockup you release and re-apply the brakes. The reality is that when it counts it rarely works, I know I was that soldier! ;-). ABS can only reduce stopping distances compared to those of the same vehicle with locked wheels skidding. Hopefully this clears up the ABS/balancing brakes/reucing stopping distances issues. D. Link to comment Share on other sites More sharing options...
Guest Peter James Posted September 1, 2013 Share Posted September 1, 2013 Dave Newell - 2013-08-31 8:48 PM Peter James - 2013-08-31 12:07 AM Dave Newell (foreign internet troll ) - 2013-08-30 10:07 PM ABS does not balance the brakes, neither front to rear or side to side...... On more advaned systems it can cut the braking pressure to the locked wheel alone. Well that is effectively balancing the brakes isn't it? My apologies for the brevity of my previous reply, I didn't have time to explain properly this morning. ABS (Antilock Braking System) does exactly what it says on the tin i.e. in the event of wheel loockup under hard braking it will release the brakes to correct the locked and skidding wheel. A locked and skidding wheel has a much lower coefficient of friction than a wheel which is still revolving but subject to braking effort plus it is not steerable once locked. Maximum braking efficiency occurs fractionly before a wheel locks. A brake imbalance is when the two wheels on the same axle give differing levels of braking for the same pedal pressure, this can be caused by a variety of factors but the most common ones are rust build up in the mechanism of the wheels brakes, whether they be disc/pad or drum/shoe. In the case of imbalance the ABS system cannot correct the imbalance, for one thing the ABS will not be activated until the pedal is pressed hard enough to lock one or more wheel(s) therefore the ABS does nothing to correct the brakes' imbalance issue. Early ABS systems would cut braking effort to the entire system in the event of a lockup, all wheels would be released before the ABS system would re-apply braking pressure, it was quite common to feel the brake pedal "pulsing" during ABS operation. More advanced ABS systems are capable of releasing the brakes only on the locked wheel and re-applying braking effort so quickly as to not inadvertently cause an imbalance (if the wheels on an axle have high braking effort applied and one wheel locks and is then released by the ABS there would be a serious imbalance across that axle albeit for a brief period of time, modern ABS systems are so fast that the imbalance is present for an insignificant moment of time. The two major purposes of ABS are to A) maintain braking effort during emergency braking periods by modulating the applied pressure to the wheels braking systems and B) to maintain steering during the same emergency braking periods by not allowing the wheels to remain locked and therefore in a skidding situation. What ABS has done is to remove the onus from the driver to brake effectively during an emergency. Some drivers, myself included, were taught "cadence braking" which is very similar to what ABS systems do but controlled by the driver, the idea is you hit the brake pedal hard and the moment you feel a wheel lockup you release and re-apply the brakes. The reality is that when it counts it rarely works, I know I was that soldier! ;-). ABS can only reduce stopping distances compared to those of the same vehicle with locked wheels skidding. Hopefully this clears up the ABS/balancing brakes/reucing stopping distances issues. D. Interesting post, I have enjoyed reading it, Thanks. I think the only difference between us is we had slightly different ideas about what constitutes balancing the brakes. Years ago brake balancing mechanisms weren't so good if they existed at all. To make matters worse I used to have to pick up semi trailers that may have been standing in a field for months so the brakes were very poorly balanced. Just a light touch on the brake pedal would have one or more wheels locking when the lorry wasn't slowing down much because the other wheels were hardly braking at all. Potentially a very dangerous situation, some drivers jacknifed, I didn't because I was a pretty slow driver to the consternation of my boss and the drivers who were unfortunate enough to be stuck behind me *-) Anyway, my thoughts were that ABS provides a sort of brake balancing thats far better than what I had then. Link to comment Share on other sites More sharing options...
Brock Posted September 1, 2013 Share Posted September 1, 2013 I know the stretch in question very well and whilst we all make mistakes, anyone doing more than 50mph on that stretch should consider whether they need a speed awareness course. I have to continually remind myself when driving a car that speed limits indicate the maximum speed allowed not the target speed. This A491 stretch used to be strewn with crashed vehicles [slight exaggeration to make a point!] particularly as a result of over ambitious driving by the young. I once went along this stretch late at night and saw a car in flames on the roadside - all four teenagers perished. I had my wife and kids with me. To tackle the number of deaths on the dual carriageways in Worcestershire, the Council took the commendable decisions, but somewhat irritating for car drivers, to reduce several speed limits on major roads from 60mph to 50mph. Derbyshire Council has done the same. I was done for speeding in Staffordshire and was glad I was because I came around a corner at far too high a speed for the traffic lights that existed about 400 yards or so ahead. If it wasn't for the flash, I could have approached those lights at 60mph and killed myself and others. I mentioned to the Council that bushes hid the sign and junction on the outside and a lorry hid the sign on the inside. Now the bushes have been removed. Co-incidence? I've also attended a speed awareness course for doing 32mph in a 30 limit in North Wales in the motorhome. Time and money well spent. I think too many of us embrace the driving habits of Toad of Toad Hall! Link to comment Share on other sites More sharing options...
Brock Posted September 1, 2013 Share Posted September 1, 2013 On the point of ABS, when I had my first car with it fitted in the 80's, I was pulled over in a routine check in Bolton. The Policeman noticed the ABS and warned me about relying on it. He said it would easily allow me to make an emergency stop and retain control of the car but the not the idiot behind me. Ever since then I've tried, but not always succeeded, in keeping a sufficient distance between me and the vehicle in front that will allow the vehicle behind me to stop without crashing into me. Link to comment Share on other sites More sharing options...
tonyishuk Posted September 1, 2013 Share Posted September 1, 2013 teflon2 - 2013-08-30 7:12 PM Mrs T - 2013-08-30 6:59 PM If everyone drove according to the limit signs then councils would not waste time and money in erecting them. The answer is in the hands of the motorist. If they didn't erect the signs we wouldn't know what the limit was. John I don't have a problem with the remarks above in principle. However if you are a "Stranger in these parts" on a piece of road with varying speed limits changing every 500 metres, some of which are hidden behind shrubbery that has not been maintained, does make the balance uneven in Mr Plodds favor. "It was 'idden behind a bush, M'lord", I don't think is an acceptable excuse although quite a valid one. Makes more sense to paint the limit on the road. (Until it becomes and Elf & Saftey matter, when a m/cyclist skids on the painted surface. Rgds Link to comment Share on other sites More sharing options...
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