My point exactly. If you had a car which behaved like this you'd find out why and set it straight, why put up with a car/caravan combination doing it?
You say:
"Never been loose on the Motorway yet so no experience at all, just thinking about it."
Very sensible post, and the answer is NEVER to exceed your experience. Towing a caravan on a Motorway is easy. But because of the high speeds of other traffic, slipstreams from trucks and coaches, sudden side winds when crossing bridges and other drivers kamikaze driving habits and attitudes towards caravanners, etc there ARE hazardous situations which all need to be 'experienced' in a controlled manner BEFORE you start thinking about overtaking.
It actually always amazes me that some people with caravans are trying to overtake at all. Some of them seem hell bent on 'arriving first'.
Well, Big Deal, but does anybody care? Your family will (or maybe won't if you kill them all) care if you spread them all over the Motorway wrecking the van, car, and holiday in the process.
WE work on the principle that "we arrive when we arrive".
Is that so difficult? I mean.....What's the rush?
OK, you might get held up here and there, but it's very rare, in our 22 years of towing caravans, that we've EVER been seriously delayed by other traffic. Sure, you'll get slow parts of the journey, but are they really such a big issue?
You can always ring the site and tell them that you are running a bit later than expected. They won't eat you!
If you allow plenty of time for your journey, and actually ALLOW for other traffic, then life becomes a lot less stressful.
Chill out. Enjoy the journey. It should be a means to getting to your site, or back home again. Not an ordeal.
Above all, take things VERY steady when you first venture on to the Motorway with your caravan. It's a learnign curve, like everything else. I'm sure you'll be fine.
Enjoy your Caravanning.
"Never been loose on the Motorway yet so no experience at all, just thinking about it."
Very sensible post, and the answer is NEVER to exceed your experience. Towing a caravan on a Motorway is easy. But because of the high speeds of other traffic, slipstreams from trucks and coaches, sudden side winds when crossing bridges and other drivers kamikaze driving habits and attitudes towards caravanners, etc there ARE hazardous situations which all need to be 'experienced' in a controlled manner BEFORE you start thinking about overtaking.
It actually always amazes me that some people with caravans are trying to overtake at all. Some of them seem hell bent on 'arriving first'.
Well, Big Deal, but does anybody care? Your family will (or maybe won't if you kill them all) care if you spread them all over the Motorway wrecking the van, car, and holiday in the process.
WE work on the principle that "we arrive when we arrive".
Is that so difficult? I mean.....What's the rush?
OK, you might get held up here and there, but it's very rare, in our 22 years of towing caravans, that we've EVER been seriously delayed by other traffic. Sure, you'll get slow parts of the journey, but are they really such a big issue?
You can always ring the site and tell them that you are running a bit later than expected. They won't eat you!
If you allow plenty of time for your journey, and actually ALLOW for other traffic, then life becomes a lot less stressful.
Chill out. Enjoy the journey. It should be a means to getting to your site, or back home again. Not an ordeal.
Above all, take things VERY steady when you first venture on to the Motorway with your caravan. It's a learnign curve, like everything else. I'm sure you'll be fine.
Enjoy your Caravanning.
Hello Keith,
I totally agree with everything you say.
I always say the minute i leave my drive with my caravan were on holiday, even if its only for the weekend. We all race around at home work etc today in our stressfull lives & so no matter what time we arrive at sites we always enjoy & never worry about traffic you cant alter it. I would rather journeys take me longer than never get there at all.
Regards
David
I totally agree with everything you say.
I always say the minute i leave my drive with my caravan were on holiday, even if its only for the weekend. We all race around at home work etc today in our stressfull lives & so no matter what time we arrive at sites we always enjoy & never worry about traffic you cant alter it. I would rather journeys take me longer than never get there at all.
Regards
David
You should remember that when it comes to overtaking you CANNOT exceed 60mph as this is the limit. when i am driving solo (without the caravan) on the motorway i will never exceed the 10% of the limit whether is know the road or not, but when it comes to towing i have a peugeot 406 hdi and tow a elddis hurricane and i never go above 60mph and i do have a stabilier fitted to the car, however i was surprised when i went on my summer hols this year that a number of other caravans were over taking me especially 4X4's, then i do overtake i am constantly monitoring the needle on the speedo dial. Not only is it more dangerous when towing but i don't fancy getting points on my license or having to tell my insurance that i have points.
Whilst in Eire this summer it is the expected practice for ALL motorists to pull on to the hard shoulder or well to the left to allow faster following vehicles to pass!
We had no concerns with broken down vehicles as you obviously don't pull over if something is blocking you way! The system works very well for the Irish.
Our van is around 26 foot long and has a large tug. I take issue with "mcgees" posting as being a little mis-leading. The front bow wave of large Artic lorries other large trucks and coaches has to go somewhere.
The bow wave effect has to escape and I don't care how big or good you rig set-up is, you must feel some effect when such vehicles overtake close to you. Other truck and coach drivers feel the effects and to state that a caravanner may not is a little worrying.
The larger the gap between you and large vehicles the lesser the bow wave effect from those vehicles.
We had no concerns with broken down vehicles as you obviously don't pull over if something is blocking you way! The system works very well for the Irish.
Our van is around 26 foot long and has a large tug. I take issue with "mcgees" posting as being a little mis-leading. The front bow wave of large Artic lorries other large trucks and coaches has to go somewhere.
The bow wave effect has to escape and I don't care how big or good you rig set-up is, you must feel some effect when such vehicles overtake close to you. Other truck and coach drivers feel the effects and to state that a caravanner may not is a little worrying.
The larger the gap between you and large vehicles the lesser the bow wave effect from those vehicles.
Hello Andrew,
I commend you for sticking to the speedlimit whilst towing, but I cannot see your logic for allowing your self to speed when in a solo car.
The law does not allow any margin for speeding, so 70mph means 70, not 77. Where there can be some margin is the way the authorities decide to apply the law, BUT there is no consistsncy to that application, some areas may allow 10% others may only allow 3%, and in theroy there can be a zero tollerance, so your licence is in jeopardy if you exceed any of the enfocable limits on the UK roads.
I commend you for sticking to the speedlimit whilst towing, but I cannot see your logic for allowing your self to speed when in a solo car.
The law does not allow any margin for speeding, so 70mph means 70, not 77. Where there can be some margin is the way the authorities decide to apply the law, BUT there is no consistsncy to that application, some areas may allow 10% others may only allow 3%, and in theroy there can be a zero tollerance, so your licence is in jeopardy if you exceed any of the enfocable limits on the UK roads.
I arrived at Heathrow yesterday afternoon and picked up a hire car. On the exit road to the M4 cars were speeding between the two roundabouts and the same on the M4 and onto the M25 where I was overtaken by two "middle aged" caravaners doing nearly 70 mph at the Staines turn off.
South bound on the M3 I felt quite unconfortable and unsafe travelling at an indicated 70mph when the average speed seems to be between 8O and 90 mph. It was much the same on the M27, I'm at a loss with UK speed limits and would suggest that many of the saintly speed limit observers are living in their own little fantasy world when reading their speedo's and reporting here.
My sat nav is set to give a long distance warning of speed cameras and mobile speed traps. You can even see a barage of the brak lights coming on in front as you approach such points on the 3 motorways.
The law may not allow any margin John L but those imposing the law here do when it chooses to suit them!
South bound on the M3 I felt quite unconfortable and unsafe travelling at an indicated 70mph when the average speed seems to be between 8O and 90 mph. It was much the same on the M27, I'm at a loss with UK speed limits and would suggest that many of the saintly speed limit observers are living in their own little fantasy world when reading their speedo's and reporting here.
My sat nav is set to give a long distance warning of speed cameras and mobile speed traps. You can even see a barage of the brak lights coming on in front as you approach such points on the 3 motorways.
The law may not allow any margin John L but those imposing the law here do when it chooses to suit them!
BigAl,
It is normal to tow at 130Kph (81 Mph) on the French autoroutes unless your gross train weight exceeds 3500Kg.
Hi euro. I didn't say a caravanner shouldn't feel any effects of a lorry overtaking, of course you will be aware of it. The effect should not be to drag your outfit across the carriageway or start a minor snake. My point is some people seem to think it's OK to counteract this by giving a wide berth, and I find that unacceptable. I believe it would be far better to use a properly balanced outfit which, apart from being a more relaxing drive, will allow full concentration on the road ahead rather than what's approaching from behind. On a different point, Andrew: Don't you think it would be better to break the speed limit by a few MPH to allow yourself back into a safe position quickly?
Hello Euro,
You have identified the point I was making, the statutes have no tollerance, however some, but not all enforcement authorities may choose to allow some latitude, and as such the degree of latitude is not universal. Regardless of the authorities policy, to travel faster than the permitted speed limit is an offence.
For some people that already have points on thier licence, any additional offence may prevent them from keeping thier levelyhood, so speed limits are important.
On another point regarding the accuracy of speedometers, current EU regulations require car manufacturers to ensure that thier speedometers do not indicate the vehicle is travelling slower than in reality (Pesimistic), so invariably your indicated speed will be faster than reality.
You mention the use of SAT NAV, some people choose to use it to give a speed reading, - for reasons that I have explianed elswhere, you cannot rely on the SAT NAV to give an 100% accurate reading of speed consistently. It has basic flaws that mean particulary at lower speeds, there is the potential for considerable and variable error, and as you have no way of knowing when the device is giving erronous output, it is foolish to rely on it as an impeachable reference, at least your speedometer has a consistent error.
Mcghee, Are you seriously encouraging some one to break the law? If you cannot overtake by staying within the speedlimit, then you should not attempt to overtake.
You have identified the point I was making, the statutes have no tollerance, however some, but not all enforcement authorities may choose to allow some latitude, and as such the degree of latitude is not universal. Regardless of the authorities policy, to travel faster than the permitted speed limit is an offence.
For some people that already have points on thier licence, any additional offence may prevent them from keeping thier levelyhood, so speed limits are important.
On another point regarding the accuracy of speedometers, current EU regulations require car manufacturers to ensure that thier speedometers do not indicate the vehicle is travelling slower than in reality (Pesimistic), so invariably your indicated speed will be faster than reality.
You mention the use of SAT NAV, some people choose to use it to give a speed reading, - for reasons that I have explianed elswhere, you cannot rely on the SAT NAV to give an 100% accurate reading of speed consistently. It has basic flaws that mean particulary at lower speeds, there is the potential for considerable and variable error, and as you have no way of knowing when the device is giving erronous output, it is foolish to rely on it as an impeachable reference, at least your speedometer has a consistent error.
Mcghee, Are you seriously encouraging some one to break the law? If you cannot overtake by staying within the speedlimit, then you should not attempt to overtake.
John I think you have got a bit mixed up.
Vehicle speedo's all over real speed as if they were to under read you would get in trouble doing an indicated 30 when in fact you were doing 32-34.
As for sat nav, it is now the required speed assesment choice for official land speed records as it is so accurate compared to any other speedo's.
I did see your comments before on sat nav speed reading, but you have it wrong in your assumptions. Speed calculations and actual navigation with satnav have different factors.
My comment was in fact related to speed cam locations and not speed recording!
Vehicle speedo's all over real speed as if they were to under read you would get in trouble doing an indicated 30 when in fact you were doing 32-34.
As for sat nav, it is now the required speed assesment choice for official land speed records as it is so accurate compared to any other speedo's.
I did see your comments before on sat nav speed reading, but you have it wrong in your assumptions. Speed calculations and actual navigation with satnav have different factors.
My comment was in fact related to speed cam locations and not speed recording!
Hello Euro,
If you read my last posting again you will see that we agree about the error in vehicle speedometers.
I am aware that your comment related to the position of speed cameras, but as an extension to the discussion and closely related is the use of sat nav as a speed indicator.
You claim my assumption is wrong about the accuracy of SAT NAV as a speed indicator. I have actually quizzed some of the manufactures of the domestic units, and the responses I got clearly indicate that the fundamental calculation is 'distance divided by time'. Distance is calculated as the difference between two positional fixes. It follows that any error in the positional fixes will translate into an error in the speed calculation.
At best the accuracy of domestic units is quoted as + or - 5m, so for low speeds that potentially becomes a significant error. With only a low number of satellites in view the error increases. There is also the quantification error of the A to D conversion which non of the domestic unit manufacture quote so it is not possible to quote SATNAV figures to better than +or- one digit.
I do not know of any official body that accepts the output form a sat nav system as being the definitive speed indicator.
Despite the reservations I have outlined above, I do accept that SAT NAV does provide a very useful comparison for speed indication, and it is possible to ascertain with reasonable confidence the error of most vehicle speedometers.
If you have other information to support your contention that speed and position are unrelated, then I would like to read it.
If you read my last posting again you will see that we agree about the error in vehicle speedometers.
I am aware that your comment related to the position of speed cameras, but as an extension to the discussion and closely related is the use of sat nav as a speed indicator.
You claim my assumption is wrong about the accuracy of SAT NAV as a speed indicator. I have actually quizzed some of the manufactures of the domestic units, and the responses I got clearly indicate that the fundamental calculation is 'distance divided by time'. Distance is calculated as the difference between two positional fixes. It follows that any error in the positional fixes will translate into an error in the speed calculation.
At best the accuracy of domestic units is quoted as + or - 5m, so for low speeds that potentially becomes a significant error. With only a low number of satellites in view the error increases. There is also the quantification error of the A to D conversion which non of the domestic unit manufacture quote so it is not possible to quote SATNAV figures to better than +or- one digit.
I do not know of any official body that accepts the output form a sat nav system as being the definitive speed indicator.
Despite the reservations I have outlined above, I do accept that SAT NAV does provide a very useful comparison for speed indication, and it is possible to ascertain with reasonable confidence the error of most vehicle speedometers.
If you have other information to support your contention that speed and position are unrelated, then I would like to read it.
John L
If you compare your wife holding the map and navigating and you reading the speedo, you can know your speed whilst your wife is still adjusting or working out your position.
I'm told via a Satnav industry insider that this in a simplified way is the difference on the Satnav. A speed calculation is being made and also another part of the system or program is calculating where the unit is and adjusting the on screen map. Positioning on the sat nav relates partly to the accuracy of the map and its integration on the sat nav system.
I understand that this means that your position shown on the screens map can be slightly out as the program is adjusting etc. It does not mean that the speed accuracy is as inaccurate as the positioning at any one time.
Re speed records. To set one you need to know how fast you are going over the timed mile or what ever. GPS is what is used to know how fast the pilot of whatever is going when attempting the records.
I've just set my Satnav and its taking positioning from 11 satellites not a triangulation from two, newer chip sets have a more accurate lock (this is why newer units are quite accurate on gradients than in the recent past) and use more satellites, all though not 100% accurate speed wise virtually all Satnavs are more accurate than any vehicle speedo.
If you run a series of tests over varying roads that show speed being two or three mph out between sat nav and speedo, the Satnav is the most accurate. You don't need to be using the Satnav in place of the speedo to know that at the speedo's indictated 53 or 53 mph or 73 or 72 mph you are actually doing 50 or 70 depending on if your speedo reads two or three mph over.
As a matter of interest running a laymans off the shelf satnav against an expensive new 2006 ships Satnav navigation system the Garmin read exactly the same speed and positioning appeared to be as accurate!
John L
If you compare your wife holding the map and navigating and you reading the speedo, you can know your speed whilst your wife is still adjusting or working out your position.
I'm told via a Satnav industry insider that this in a simplified way is the difference on the Satnav. A speed calculation is being made and also another part of the system or program is calculating where the unit is and adjusting the on screen map. Positioning on the sat nav relates partly to the accuracy of the map and its integration on the sat nav system.
I understand that this means that your position shown on the screens map can be slightly out as the program is adjusting etc. It does not mean that the speed accuracy is as inaccurate as the positioning at any one time.
Re speed records. To set one you need to know how fast you are going over the timed mile or what ever. GPS is what is used to know how fast the pilot of whatever is going when attempting the records.
I've just set my Satnav and its taking positioning from 11 satellites not a triangulation from two, newer chip sets have a more accurate lock (this is why newer units are quite accurate on gradients than in the recent past) and use more satellites, all though not 100% accurate speed wise virtually all Satnavs are more accurate than any vehicle speedo.
If you run a series of tests over varying roads that show speed being two or three mph out between sat nav and speedo, the Satnav is the most accurate. You don't need to be using the Satnav in place of the speedo to know that at the speedo's indictated 53 or 53 mph or 73 or 72 mph you are actually doing 50 or 70 depending on if your speedo reads two or three mph over.
As a matter of interest running a laymans off the shelf satnav against an expensive new 2006 ships Satnav navigation system the Garmin read exactly the same speed and positioning appeared to be as accurate!
If you compare your wife holding the map and navigating and you reading the speedo, you can know your speed whilst your wife is still adjusting or working out your position.
I'm told via a Satnav industry insider that this in a simplified way is the difference on the Satnav. A speed calculation is being made and also another part of the system or program is calculating where the unit is and adjusting the on screen map. Positioning on the sat nav relates partly to the accuracy of the map and its integration on the sat nav system.
I understand that this means that your position shown on the screens map can be slightly out as the program is adjusting etc. It does not mean that the speed accuracy is as inaccurate as the positioning at any one time.
Re speed records. To set one you need to know how fast you are going over the timed mile or what ever. GPS is what is used to know how fast the pilot of whatever is going when attempting the records.
I've just set my Satnav and its taking positioning from 11 satellites not a triangulation from two, newer chip sets have a more accurate lock (this is why newer units are quite accurate on gradients than in the recent past) and use more satellites, all though not 100% accurate speed wise virtually all Satnavs are more accurate than any vehicle speedo.
If you run a series of tests over varying roads that show speed being two or three mph out between sat nav and speedo, the Satnav is the most accurate. You don't need to be using the Satnav in place of the speedo to know that at the speedo's indictated 53 or 53 mph or 73 or 72 mph you are actually doing 50 or 70 depending on if your speedo reads two or three mph over.
As a matter of interest running a laymans off the shelf satnav against an expensive new 2006 ships Satnav navigation system the Garmin read exactly the same speed and positioning appeared to be as accurate!
Hello again Euro
The analogy you make is not very close at all. The reason is that in a Sat Nav, you have a common source of information, that is the GPS receiver. If that cannot accurately ascertain its position, then any calculation based on the GPS unit , be it speed or map location will also be in error.
Sat nav positioning for a moving vehicle is always going to be slightly out because of the time to integrate the signals, and the time to calculate and plot the position.
I am not saying that GPS cannot be reasonably accurate, just that you have to accept that GPS/SatNav is dependant on a system that is prone to errors especially when the number of satellites acquired is low.
It is foolish to assume that SAT NAV is always giving good speed information. Just as an example, I travel through Birmingham, and on open stretches of road (i.e. not underpasses), I have witnessed my Satnav give speed indications as low a 16mph, and as high as 56mph whilst travelling at or around 40mph.
I sense that we are not going to be able to agree on this issue, both of us believing we are right based on the evidence we have individually gathered. As a result I will continue to use Sat Nav speed indications with caution.
The analogy you make is not very close at all. The reason is that in a Sat Nav, you have a common source of information, that is the GPS receiver. If that cannot accurately ascertain its position, then any calculation based on the GPS unit , be it speed or map location will also be in error.
Sat nav positioning for a moving vehicle is always going to be slightly out because of the time to integrate the signals, and the time to calculate and plot the position.
I am not saying that GPS cannot be reasonably accurate, just that you have to accept that GPS/SatNav is dependant on a system that is prone to errors especially when the number of satellites acquired is low.
It is foolish to assume that SAT NAV is always giving good speed information. Just as an example, I travel through Birmingham, and on open stretches of road (i.e. not underpasses), I have witnessed my Satnav give speed indications as low a 16mph, and as high as 56mph whilst travelling at or around 40mph.
I sense that we are not going to be able to agree on this issue, both of us believing we are right based on the evidence we have individually gathered. As a result I will continue to use Sat Nav speed indications with caution.
John you have lost me, I use Garmin as they are based on military technology and not so much on gimicks of joe public drivers for joe public drivers
If have such wide speed readings with your Satnav at fixed speeds you are not receiving clear signals posibly due to positioning of your unit aerial or you have a dodgy unit.
GPS basic units give the most accurate speed readings available to the public.
There are times when due to being un sighted the speed reading can be wrong. But the simple idea is that you take a number of readings on level open roads between speedo and satnav at constant speeds. You then know as best as you can the difference between the less accurate speedo and the near as damit accuracy of the satnav,it is not a case of sitting watching the satnav speed reading.
My wife and I have Garmins and neither, or our older spare that we lend to visiting friends have ever shown anything like 16 - 56 mph at around 40mph and that inludes on all sorts of driving.
I suggest you try a better position for your Satnav or maybe an external aerial as some cars window treatments can effect the readings and the speed differences you quote suggest a big problem.
If have such wide speed readings with your Satnav at fixed speeds you are not receiving clear signals posibly due to positioning of your unit aerial or you have a dodgy unit.
GPS basic units give the most accurate speed readings available to the public.
There are times when due to being un sighted the speed reading can be wrong. But the simple idea is that you take a number of readings on level open roads between speedo and satnav at constant speeds. You then know as best as you can the difference between the less accurate speedo and the near as damit accuracy of the satnav,it is not a case of sitting watching the satnav speed reading.
My wife and I have Garmins and neither, or our older spare that we lend to visiting friends have ever shown anything like 16 - 56 mph at around 40mph and that inludes on all sorts of driving.
I suggest you try a better position for your Satnav or maybe an external aerial as some cars window treatments can effect the readings and the speed differences you quote suggest a big problem.
Hello Euro
All SATNAV is based on military technology, as it was the US military that established the GPS satellites!
I differentiate between domestic and professional GPS systems; in so far as vehicle based systems as available to the domestic market will never be able to offer the guaranteed accuracy of surveyors specialised systems. Surveyors systems take minutes to establish and check to centimetre or better accuracy, such time would be wholly impractical for a moving vehicle.
I have also compared different units and all exhibit the same potential for errors. It is not windscreen related in my case, but I agree that I have not been getting clear signals, - buildings and other normal obstructions found in cities cause some signal degradation and therefore loss of accuracy.
Most of the time it is not significant but occasionally for few moments the speed indication is clearly wrong.
And that is the point, when you have a degraded signal or loose sight of a satellite the positional accuracy of the GPS unit is also degraded. That degradation has to be passed onto any subsequent calculations made by the GPS or SatNav elements, and thus is reflected in speed calculations and map positioning. What you don't know is when such a condition exists.
You cannot divorce the speed calculations from any GPS error. The speed is calculated from GPS data. For that reason you cannot use SatNav as a certified source of speed information.
Yes - most of the time it represents a major improvement on speed indication, but you must not blindly accept it as gospel truth, and there is still the issue of the analogue to digital conversion, If the SatNav has calculated your speed as 60mph, does it mean 59.5 or 60.5?
I think we have exhausted this topic and I do not intend to contribute further to this aspect of this thread.
All SATNAV is based on military technology, as it was the US military that established the GPS satellites!
I differentiate between domestic and professional GPS systems; in so far as vehicle based systems as available to the domestic market will never be able to offer the guaranteed accuracy of surveyors specialised systems. Surveyors systems take minutes to establish and check to centimetre or better accuracy, such time would be wholly impractical for a moving vehicle.
I have also compared different units and all exhibit the same potential for errors. It is not windscreen related in my case, but I agree that I have not been getting clear signals, - buildings and other normal obstructions found in cities cause some signal degradation and therefore loss of accuracy.
Most of the time it is not significant but occasionally for few moments the speed indication is clearly wrong.
And that is the point, when you have a degraded signal or loose sight of a satellite the positional accuracy of the GPS unit is also degraded. That degradation has to be passed onto any subsequent calculations made by the GPS or SatNav elements, and thus is reflected in speed calculations and map positioning. What you don't know is when such a condition exists.
You cannot divorce the speed calculations from any GPS error. The speed is calculated from GPS data. For that reason you cannot use SatNav as a certified source of speed information.
Yes - most of the time it represents a major improvement on speed indication, but you must not blindly accept it as gospel truth, and there is still the issue of the analogue to digital conversion, If the SatNav has calculated your speed as 60mph, does it mean 59.5 or 60.5?
I think we have exhausted this topic and I do not intend to contribute further to this aspect of this thread.
I respect your point John.
All Satnav uses at present military satellites, my point re garmin is that their background is more based on military and professional Satnav systems not that of that of selling a popular new product to the mass public market. Maybe I should have clarified that.
Maybe consider the following -
If your satnav can take an external (best buy is Maplins @ around
All Satnav uses at present military satellites, my point re garmin is that their background is more based on military and professional Satnav systems not that of that of selling a popular new product to the mass public market. Maybe I should have clarified that.
Maybe consider the following -
If your satnav can take an external (best buy is Maplins @ around
Just to help clear up a point, I found this for you John.
"The GPS uses doppler shift (of the signal from the satellites) to measure speed. It is nothing to do with the frequency
of position readings. "
Also
"modern in car units with latest Chipsets are as accurate or better than satnav positioning used on multi million
"The GPS uses doppler shift (of the signal from the satellites) to measure speed. It is nothing to do with the frequency
of position readings. "
Also
"modern in car units with latest Chipsets are as accurate or better than satnav positioning used on multi million
Hello euro; I was intrigued by the comment "You may also be aware that we have satnav due to a famous plane incident, that incident persuaded the US to open the military systems to public use!" and ask to what this refers.
What I DO remember (being a GPS user since 1996) is that the US used to purposely add an error signal (known as Selective Availability) to ensure that the non military use of GPS was not as accurate as military systems. It was President Bill Clinton 2000 who removed this error signal and, within seconds our GPS system were all accurate to within about 5-10 meters as opposed to 100 metres. This made a huge difference when trying to locate a specific sand dune in the Arabian desert !!
Enjoy
John
What I DO remember (being a GPS user since 1996) is that the US used to purposely add an error signal (known as Selective Availability) to ensure that the non military use of GPS was not as accurate as military systems. It was President Bill Clinton 2000 who removed this error signal and, within seconds our GPS system were all accurate to within about 5-10 meters as opposed to 100 metres. This made a huge difference when trying to locate a specific sand dune in the Arabian desert !!
Enjoy
John
Hello Euro, long time no speak,had a month away if you get my meaning.Anyway getting back to original topic, I feel safer overtaking trucks rather than the opposite because Im in control and not the trucker who is on the limiter, and takes two weeks to overtake.I also feel less pull when emerging from the front of a truck than I do when a truck starts to pass me.Like Mcghee, I cant say I have ever had any problems apart from the slight pull when overtaking.I would not ask anyone to do more than they feel safe doing, but I think sometimes things are exaggerated which are, at the end of the day,characteristics of towing.
hi josef ,i reguarly get 38mpg towing 1300kg abbey with a 120 hp stillo .its been chipped although.i get from j18 m6 to exeter services on just over half a tank,travelling through the night.
After the Russians shot down the Korean flight Reagan and Co opened up satnav to commercial airlines leading that lead on to the little box sat on many a dashboard.
"1983 - Following the Soviet downing of Korean Air flight 007, President Reagan offers to make GPS available for use by civilian aircraft, free of charge, when the system becomes operational. This marks the beginning of the spread of GPS technology from military to civilian aircraft. "
I understand John that the error signal that could put you a 100 metres out was considered OK for keeping in flight commercail flights out of unfriendly airspace whilst giving the Americans the upper hand for its military use. As many other uses for sat nav have developed Clinton opened it up fully and with egnos coming on stream we will have even better positioniing and be free of the americans pulling the plug on a whim.
I'm with you Geordie, my point was more pointed at new caravanners who may take the " no effect " kind of comment as being literal.
The bow wave effect and the wind being forced between large truck and caravan has less effect the wider the gap between the two in my experience. I don't suggest swerving to the left if a truck passes , but keeping a wide as gap as you can does help relieve the buffeting effect in my experience.
"1983 - Following the Soviet downing of Korean Air flight 007, President Reagan offers to make GPS available for use by civilian aircraft, free of charge, when the system becomes operational. This marks the beginning of the spread of GPS technology from military to civilian aircraft. "
I understand John that the error signal that could put you a 100 metres out was considered OK for keeping in flight commercail flights out of unfriendly airspace whilst giving the Americans the upper hand for its military use. As many other uses for sat nav have developed Clinton opened it up fully and with egnos coming on stream we will have even better positioniing and be free of the americans pulling the plug on a whim.
I'm with you Geordie, my point was more pointed at new caravanners who may take the " no effect " kind of comment as being literal.
The bow wave effect and the wind being forced between large truck and caravan has less effect the wider the gap between the two in my experience. I don't suggest swerving to the left if a truck passes , but keeping a wide as gap as you can does help relieve the buffeting effect in my experience.
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