Speedo Inaccurate

[Maverick]

As to the 'big picture', what we now have are mandated speed limits that (here in Victoria, at least), are to be rigidly observed almost at pain of death, and electronic speed measuring devices that are (or are legally deemed to be, which may not be the same thing) greatly more accurate than the 'made down to a price, not up to a standard' units fitted to the vehicles we drive.

That's what's wrong — the 'near enough is good enough' approach by manufacturers that's not merely tolerated, but (in the interest of State revenue? — we regularly see income from fines included in annual budgets) even legislated for.

The UN standards adopted by our country in our ADR's means that you speedo cannot display a lower speed than you are traveling at.

The previous ADR's allowed + or - 10%.

And to say that it's always been so is missing the point — with few exceptions, speedo's and other automotive instruments have traditionally been cheap devices that made a 'near enough' guess, but the legislation governing the speeds we travel at and the harsh enforcement thereof has not always been as it is today.

The new regulations means you can't get done for speeding if you're looking at the speedo.

This reads like a rant — maybe it is... but I'm quite sure speed measuring devices in cars and trucks can be made to be accurate and believable. With the technology available today, they need no longer be triggered from any rotating/wearing part of the vehicle itself.

There isn't any technology now that can give you a reliable indicator of your speed without using a rotating/wearing part like the tyres. The GPS system is not really suitable for use as in tunnels, cuttings, mountainous areas and so on it will suffer from error or not work at all.

I don't really see any major problems with the current system which works with a known amount of error.

[KWICKS]

The new regulations means you can't get done for speeding if you're looking at the speedo.

Only crashing becasue you had your eyes off the road fearing speed cameras...

[Corey_R]

I read your post Idle, and whilst you first appear to be arguing against me, your 'rant' basically just gives all the justification that's needed for the car manufacturers to be doing what they are being mandated by ADR's to do. And Maverick clarified all that needed to be, so

@KWICKS - no not at all. You only need to do that with OLD cars which DON'T have this '(7)% tolerance' like the VW cars do. That's yet another reason for this situation

[Idle]

There isn't any technology now that can give you a reliable indicator of your speed without using a rotating/wearing part like the tyres. The GPS system is not really suitable for use as in tunnels, cuttings, mountainous areas and so on it will suffer from error or not work at all.

I don't really see any major problems with the current system which works with a known amount of error.

That's just the point — it isn't a known amount of error, it varies between vehicle makers and between individual instruments — even by the viewing angle of the driver.

And there are non-rotating methods of measuring speed, varying from very cheap (your 'laser' computer mouse, for example, that can be made for a dollar or so, is surprisingly accurate, works on pretty much any surface and uses technology that could easily be scaled up to what's required for road vehicles if the demand were there) to the generally detested speed cameras now in world-wide use.

Even the focusing sensor systems of modern digital cameras could probably be adapted without too much trouble, and I don't doubt there are others I've not even heard of.

Meanwhile, I suppose, I'll continue either feeling nervous when I exceed the indicated speed or tolerate having it made clear that I'm getting in the way of progress when I don't.

Incidentally, in Victoria we have an advertising campaign called "Wipe Off 5" — if you add that to the inbuilt 5 to 10% error... (how slow can you go?)

I think I've now had a bit more than my 2c worth — maybe 5c?

[Topend]

I'm glad to see I am not the only one that believes the notion of an error built into the speedo in order to protect drivers from themselves is silly.

Lets now apply this to aircraft so pilots don't exceed their Vne (never exceed speed). Makes no sense there either.

A GPS is not the only give away to the speedo being inaccurate. Other traffic whizzing past is another and in my case my wife accusing me of speeding when I went past her in my Landcruiser.

A few have admitted to calculating in their head the corrected indicated speedo reading to be driving to be at the true speed limit. If this is happening, and I am doing this too, what is the point of the error?

Dave.

[Corey_R]

Lets now apply this to aircraft so pilots don't exceed their Vne (never exceed speed). Makes no sense there either.

Lol - are you seriously trying to compare aircraft pilots to drivers! Um yeah, an aircraft pilot goes through so much more training and certification prior to acquiring their license that it's not really a comparision at all....

[Topend]

Lol - are you seriously trying to compare aircraft pilots to drivers! Um yeah, an aircraft pilot goes through so much more training and certification prior to acquiring their license that it's not really a comparision at all....

How much driver training does it take to read and interpret a speedo?

[Zeke]

There's a note somewhere in the Golf MK6 handbook that says drivers should not put there heads to close to the exaust pipe whilst the engine is running as the inhaling of exaust fumes may cause random acts of babling and self pontification on web forums.

Some off you haven't been reading the handbook have you.

[Corey_R]

How much driver training does it take to read and interpret a speedo?

Apparently lots. How many people get booked for speeding in NSW each year? All the speed cameras are SIGNED and yet people STILL get booked for speeding. Obviously there are hundreds of thousands of drivers on the NSW roads who can't read and interpret their speedo correctly

[Topend]

Apparently lots. How many people get booked for speeding in NSW each year? All the speed cameras are SIGNED and yet people STILL get booked for speeding. Obviously there are hundreds of thousands of drivers on the NSW roads who can't read and interpret their speedo correctly

Do you really believe drivers speed because they can't read and interpret their speedo?