[QUOTE]This latest IAM study reviews and reappraises the risk. It
analyses 150,000 motorcycle casualties over seven years,
highlights where and when motorcyclists are most at risk

snip
/QUOTE]

Did they REALLY analyse 150 000 casualties? And are they saying it took them seven years, or the casualties covered a period of 7 years.

How did they have the resources to do that?

Even at just 5 minutes each, working for 40 hours a week that's 6 years' work. I can just picture an IAM office wonk doing the analysis.

[quote=slowsider;994574]

This latest IAM study reviews and reappraises the risk. It
analyses 150,000 motorcycle casualties over seven years,
highlights where and when motorcyclists are most at risk

snip
/QUOTE]

Did they REALLY analyse 150 000 casualties? And are they saying it took them seven years, or the casualties covered a period of 7 years.

How did they have the resources to do that?

Even at just 5 minutes each, working for 40 hours a week that's 6 years' work. I can just picture an IAM office wonk doing the analysis.

I'm assuming they just grabbed the headline figure from government stats. The latest I have between 03 and 05 they averaged about 26,000 a year, so multipy 26k x 7 and you have roughly their 150k!

PS, link to a RoSPA study.

Originally Posted by Adam

I can assure you, as a regular driver of HGVs, that has never been the case for any sign I have ever seen.

Well, I don't drive HGVs, and not at night, so I'll bow to your experience.

However, that may be because you're a good driver, check the signs early, and aren't looking at them when it happens.

As retro-reflective material 'improves' it does so - largely - by reducing the size of the cone of reflectivity so that more of the light hitting the surface is returned to it's source.



And as that cone reduces to a narrower angle the reflected light seems brighter - what you were complaining about - but also less light will be reflected outside of the cone. Retro-reflective material can't increase light, only control where it goes.



The driver of a very large truck sits well above his headlights and therefore is further away from the center of the cone. He sees the same sign as less bright.

Basics | ATSSA Retroreflectivity Clearinghouse

Originally Posted by Horse

However...

Sure, I'm aware of the theory. However, like I said, IME, it's not often (can't say never as I haven't driven past all roadsigns in the UK at night) the case, mainly because the designers of the reflectors are clever enough to not just use one type of reflector on it.

Originally Posted by Adam

Sure, I'm aware of the theory. However, like I said, IME, it's not often (can't say never as I haven't driven past all roadsigns in the UK at night) the case, mainly because the designers of the reflectors are clever enough to not just use one type of reflector on it.

I think you'll find it's a leedle bit more than a theory

But the point is that many councils are now - unnecessarily - specifying high-grade reflective material for signs.

You'll also find that reflective coatings come in a number of grades, and they won't be mixed on a single sign surface. Higher-grades are required to be CE 'watermarked'.

Originally Posted by Horse

I think you'll find it's a leedle bit more than a theory

It's the same sort of "theory" that says because I had one off last year I will have another within a month or tqwo. Its possible, but not likely (cos I didn't).
So yes, while the science is fact, what I meant was it's leedle more than theory.
Clearly, or I wouldn't be seeing many signs.

But the point is that many councils are now - unnecessarily - specifying high-grade reflective material for signs.

Sure. That was kinda my point way back when.

You'll also find that reflective coatings come in a number of grades, and they won't be mixed on a single sign surface.

I don't mean different types of surfaces, I mean different types/shapes of reflectors within a single surface.

Originally Posted by Adam

So yes, while the science is fact, what I meant was it's leedle more than theory.
Clearly, or I wouldn't be seeing many signs.

I didn't say you wouldn't see them.

I said: HGV drivers sat some way higher than their vehicle's lights can't as they get closer to the sign


And it's not theory, it's science, innit?

Originally Posted by Adam

I don't mean different types of surfaces, I mean different types/shapes of reflectors within a single surface.

As I said:

Originally Posted by Horse

they won't be mixed on a single sign surface.

(Perhaps I should have put 'typically' in there.)

But if I'm wrong I'm happy to be corrected

Originally Posted by Bike Breaker

But they specify what they're led to believe (by the safety people who know these things ) is better for seeing.

More of an 'arms race' by the manufacturers.

Originally Posted by Bike Breaker

Do you think the dazzle problem could be because the signmakers/specifiers are a bit behind the times? I don't know all the science behind it, but if I remember my physics lessons (yes they had physics lessons in the 60s-70s ) reflected light is never greater than the original source but for a given reflective surface, the brighter the source, the brighter the light coming back. Perhaps the designers were working on old lighting specifications and hadn't appreciated that, in 20 years time, vehicles would have such strong beams.

Basic history (AFAIK) is that the first retro-reflective sheeting dates back to the 1940s, with micro-prismatics coming in in the 1980s (although the 'prism' idea had been used in, for example, rear reflectors for decades longer).

The early stuff returned very little light, perhaps 8%, then by the 1970s this was up to 15%.

Micro-prismatic material (IIRC invented by Reflexite) gradually pushed this up to 30%, with the very latest versions (such as 3M's DG3) returning over 50%.

Trouble is, this has coincided with halogen, and HID, lamps.

However, looking on the bright side (groan), having a significantly higher % return allows for 'spill' outside of the main cone of reflection without reducing (compared to earlier materials) that cone's light.

Google BS EN 12899-1:2007 if you really want to know about signs, 'ETA' and the various reflectivity classes

Seen the videos of the 'crumbling' (as opposed to toppling) lamp standards?

Originally Posted by dodgy

Passive safety signposts have more than a future - they have a present. All new signs on roads with limits of 50mph or greater must have them

The Times article said they must be installed on all "new roads" with a limit of 50mph or over.

KCC have just replaced a bunch of signs on a 50mph which had the conventions single aluminium pole supporting it with a new arrangement that uses TWO aluminium poles side by side.

I'm bloody sure these aren't "passive safety".

Originally Posted by The Spin Doctor

The Times article said they must be installed on all "new roads" with a limit of 50mph or over.

KCC have just replaced a bunch of signs on a 50mph which had the conventions single aluminium pole supporting it with a new arrangement that uses TWO aluminium poles side by side.

I'm bloody sure these aren't "passive safety".

You'd have to check the wall thickness of the tubing to be sure. (One plus one may not equal two )

Originally Posted by The Spin Doctor

The Times article said they must be installed on all "new roads" with a limit of 50mph or over.

I can see how that's going to work, they will just put a 50mph limit on as many new roads as possible