Stealth tax

[GrasB]

Doesn't exist, crap idea, no testing done, might I refer the arguing pea brains to this:-

http://news.bbc.co.uk/1/hi/7803997.stm

There's plenty more information around but don't let a bit of reading et in the way of your inate knowledge of the facts

Actually I have a fair amount of reading done on this subject & I'm still convinced that no one has come up with a truly reliable system because they use GPS! If you're relying on GPS, which most of these systems seem to, they have not solved the problem of roads close together & accuracy. 3M 100% of the time doesn't happen & thus you have a potential & serious problem.

 

[MacB]

Actually I have a fair amount of reading done on this subject & I'm still convinced that no one has come up with a truly reliable system because they use GPS! If you're relying on GPS, which most of these systems seem to, they have not solved the problem of roads close together & accuracy. 3M 100% of the time doesn't happen & thus you have a potential & serious problem.

You seem to have a fair idea of the problems that would occur. Can you post a link to your detailed reasearch so that we can review it? Or are you just saying, ugh, don't like that idea?

 

[GrasB]

No specific research but I'm totally unconvinced by any system based on GPS. The reason is simple. Not one person has ever shown me a GPS device which didn't wander +/- 3 m from my position when completely stationary. This is enough to change your location of roads in at least 5 places I have been. In short, it's a technology preview & not a totally robust system. If there's the possibility of a simple sampling error causing a car on an NSL road being limited to 30 or 20mph then the system is unreliable. From all the research I've read this is a real possibility thus unsuitable for general use.

As for limiting, in principle I actually like the idea but I would always give some headroom say +5% 40mph or lower limits & +10% on higher limits. The reason being you have to consider people miss-judging things & leading to a situation where the easiest get out is forwards a bit quicker.

 

[MacB]

here's some more detail:-

http://users.tpg.com.au/users/mpaine/speed.html

this gives a fairly rounded view, maybe you have some links as well?

 

[thomas]

Doesn't exist, crap idea, no testing done, might I refer the arguing pea brains to this:-

http://news.bbc.co.uk/1/hi/7803997.stm

There's plenty more information around but don't let a bit of reading et in the way of your inate knowledge of the facts

That video kind of shows why it'll never be introduced doesn't it. The ministers want it to be voluntary. Why? Because it's just a political no-no that no one else would touch it. The video also seems to be different in places to your idea.

I think another potential problem with things like this is it allows drivers to not pay as much attention. If they're not looking for speed signs, what other signs do people start to not look for? Then do people stop looking for as many hazards because of it? That seems to be the problem with a lot of modern, car safety equipment.

As GrasB has been saying, I think it is reasonable to say that any GPS system would at times get confused. On a 30mph limit, going under a motorway...signal gets confused and all of a sudden you're doing 70.....or worst, system gets confused at 70 and takes you down to 20. Other drivers cars don't get confused, but they do and end up rear ending them.

 

[BentMikey]

So who has the bigger willy?

 

[thomas]

So who has the bigger willy?

. Me. I've been using it to type from my bed

 

[Norm]

Clever Dick.

 

[BentMikey]

. Me. I've been using it to type from my bed

You forgot to be honest - by the time you'd pulled it to that length, it was only as thin as a paperclip. Students, eh!

 

[Dan B]

No specific research but I'm totally unconvinced by any system based on GPS. The reason is simple. Not one person has ever shown me a GPS device which didn't wander +/- 3 m from my position when completely stationary.

Well, that problem is easy enough to fix in a system that's actually integrated with the car: if the wheels are not going around, the position cannot have changed. (Driving on sheet ice notwithstanding, but I suggest that the speed limit is the least of your concerns when driving on sheet ice)

If the system has GPS plus inertial navigation plus a little routing information (i.e. a map which shows where the roads meet and where they merely run parallel) it can deduce from that that you *haven't* leapt the hedge between the dual carriageway and the country lane adjacent - in most cases not all that difficult. The hardest bits would be slip roads and suchlike, but I'm sure there are way s around that too

Which is not to say that I think it's a good idea anyway, just that there's no reason it shouldn't be a feasible one

 

[thomas]

You forgot to be honest - by the time you'd pulled it to that length, it was only as thin as a paperclip. Students, eh!

If it was a bit longer it could make it way down to the toilet while I'm still having a lie in

 

[BentMikey]

I had thought that there were specialist GPS systems that can position to within fractions of a cm. Might be rather expensive I guess!

 

[Davidc]

My Garmin Edge always places me on the correct side of the road.

So does my old Navman 510 (now relegated to bike use). A recent TomTom isn't as good though.

The best I have is a Garmin Foretrex. Its a bit old now but still works well. It is normally good to about 1.5m, and better if it's given time to settle. It generates 6 + 6 digit NGR references which are good to the point of telling you if you're on the pavement or road! Its vertical (height) measurement isn't as good though. Its page 1 display is also very conservative about accuracy.

The new European satellite positioning system is supposed to be better than GPS (if it gets built) and is partly designed with vehicle compliance and automation in mind.

A long way from the OP though.

 

[Rhythm Thief]

Regardless of the technical feasibility of GPS speed control, I'm still not convinced it's actually desirable. I think you'd just end up with those whose limiters were set to 30.5mph (or 40.5, or 60.5) tailgating those whose limiters were set to 30mph, rather in the manner that lorries tailgate each other on the motorway. Whether tailgating is more or less dangerous than speeding I don't know, but I don't think compulsory limiting is quite the trouble free solution that a few on here seem to think it is.

 

[thomas]

Regardless of the technical feasibility of GPS speed control, I'm still not convinced it's actually desirable. I think you'd just end up with those whose limiters were set to 30.5mph (or 40.5, or 60.5) tailgating those whose limiters were set to 30mph, rather in the manner that lorries tailgate each other on the motorway. Whether tailgating is more or less dangerous than speeding I don't know, but I don't think compulsory limiting is quite the trouble free solution that a few on here seem to think it is.

Depends on the situation really. You could do 70mph in a 30mph zone and you'll never hit the car in front (even if they do an emergency stop), if you're not tailgating and leaving a sensible stopping distance.

I'm not saying that doing 70mph in a 30 doesn't come with a billion other problems though