Safe Speed Forums

How severe the hazard is? There are only centre lines, hazard lines and double white line systems. I hardly think we're going to be able to judge our entry speed into a bend from those!

But the cats eyes show us the curve...

_________________
Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

It sounds like I live quite close to Twister, and I fully agree with Twister's assessment of the standard of the roads around here. The decline in the quality of cats' eyes is real, and not to do with declining eyesight.

When an unlit motorway (such as much of the M4) veers off to the left, and one is in the outer lane, at night, in the rain, with a clean windscreen, myopia or not, that outer white line is not sufficiently visible.

Add a sudden torrent of rain, or spray from lorries and your visibility can be cut in an instant to dangerous levels.

With all the roadworks that have taken place on the M4, it is really rather surprising that our 'safety-conscious' government did not see fit to furnish the outer lane with cats' eyes. I guess we're not paying enough taxes.

_________________
Say NO to Nanny.

I love the cats eyes we have on the A590, which don't just rely on reflecting your headlights, but stay lit (I'm not quite sure how they work, but basically it's like driving down a landing strip with the landing lights turned on!) It makes it so much easier not only to see where the road is, but to see where it's going to go in 50 metres' time.

I can't understand why they would be removing cats eyes when resurfacing roads - I find driving at night without them very tricky, especially when the centre lines are faded and not picked up clearly by my headlights (the dipped beam on Mk1 Corsas is appalling at best, which doesn't help.)

Personally I'd like to see a requirement that all A roads and above have decent, visible cats eyes along their entire length. Find the money by stopping infiltrating our towns with needless 'street furniture'!

_________________
-mike[F]
Caught in the rush of the crowd, lost in a wall of sound..

The length of the line depicts the severity of the hazard, try it next time you are driving.




Unable to see round curves, hence unable to see the path of the cats eyes, only suitable for open roads.

That's if their are any cats eyes fitted anyway, and even where they are fitted, they are mainly missing their reflector's.

Main roads are OK, they are changed more regulary, however it is not the main roads that create the bigger hazards, whilst cornering

_________________
Steve

I think you will find there are only short, long and solid lines, there are no in between lengths.

The longer dashes indicate there is a hazard, not the severity of the hazard.

To make things worse many councils have replaced this system with almost blanket hatchings and red tarmac.

So if the cats eyes stop, should you come to an almost halt, as you are about to turn a right angle


Or is it more the normal, the cats eyes are missing or scrubbed off by cornering traffic, or they run out of them the last time they resurfaced



Only if they are their, the white lines are always in place, they can be relied on

Cats eyes are an unknown quantity, if they were installed on every road, and maintained, i would agree.

_________________
Steve

Very short lines, depict a straight road, without hazards.

The lines gain in length on approach to hazards.

_________________
Steve

You have Percy Shaw To thank for these back In 1933. The only cats eyes you see In the road these days are dead ones.

_________________
RoADA Member -GOLD 2008
If you don't know where you are going, any road will get you there.

Yes and no.

I am sure we are saying the same thing in different ways but to be certain...

The lines switch from short to long on the approach to a hazard. They do not progressively lengthen.

Short.


Long.


From http://www.highwaycode.gov.uk/signs09.shtml

The lines don't mean a thing anyway, as so many places just have solid white lines as a matter of policy. Along with SLOW written on the road every 100 yards whether there is a hazard or not, so you have no idea when to really slow down as most of them are cries of wolf.

If the cats eyes are missing from the far end of a curve such that it gives the impression of the road suddenly doing a right-angle, then your beloved white lines aren't going to be of any use to you either, because in the mid-distance where cats eyes are truly useful in giving you advance notice of the course of the road, you wouldn't be able to make out the lines...



Really? White lines are always in place? More to the point, white lines are always in place, well maintained, and clearly visible in all conditions? If the road has been so badly maintained such that all the cats eyes are missing, then chances are the white lines won't be in a particularly good state either. Throw in a bit of rain to wet the surface of the road and more often than not you find the lines (even those in good condition) seem to disappear entirely. True, there are certain weather conditions when cats eyes are useless as well, but I can't think of any when white lines would remain useful whilst catseyes were rendered useless.




It doesn't matter whether they're installed on every road or not, what matters is what you do with the information they provide when they ARE installed. Earlier you implied that, even when cats eyes are present, it would still be better to concentrate on the white lines.

If you believe that, then do you also believe we should simply rip out all the existing cats eyes on the grounds that we'll never have 100% coverage of the UK road network?


I remember very well a few years ago driving across the Pennines on the M62 early in the morning (pre-dawn) and hitting a bank of thick fog. No advance warning, no way of seeing it in the distance, so no chance to get off the motorway before reaching it. Creeping along in L1 at something like 20MPH, knowing that there was a junction somewhere just up ahead... did I know I'd reached it because I saw the white line to my left turn from solid to dashed? No. The first indication I had was seeing the dim glow of the catseyes turn from red to green.

Granted, a few seconds later the dashed white lane came into view, so the catseyes didn't provide much advance notification. But the fact remains that if I'd been relying solely on the white lines for guidance I'd have had less warning about the start of the slip road and I'd have been spending more time looking sideways for a change in the white line than in looking further forwards (which also meant being able to scan the lane ahead) for a change in the cats eyes.


In short, it doesn't matter how much or little extra information cats eyes provide to you, it's information you wouldn't have if you just relied on white lines. Ignoring that information really doesn't make sense.

I found this on a forum some years ago:

To those interested in possible EU banning of night driving by the elderly, I passed this to one of my sons who is a lighting researcher. His response follows.

There are two common pathologies which affect older drivers.

1. Macular Degeneration, which means that the most sensitive area of the retina (the fovea, used for detailed resolution) becomes progressively pigmented as the person ages, and becomes less sensitive to light. This happens pretty much uniformly among the population (ie only small variations among individuals, normal 20-year olds do not have it), in much the same way as hearing loss. The effect of macular degeneration is that higher illumination levels on the roadway are required. Existing recommendations already cover typical levels of macular degeneration in older drivers.

2. Crystallisation of the lens and cornea. This is less uniform across the population, although again it is associated with age and is not found in normal 20 year olds. The upshot of this is that incoming light is scattered across the retina, causing a "veiling luminance" ie a yellow-orange (in the case of sodium lights) tinge across the whole field of view which obscures objects such as obstructions on the carriageway. Increasing illumination on the roadway does not improve visual conditions for drivers with scattering problems - the only solution is to use low-glare lighting, i.e. high-pressure sodium or metal halide lamps in reflectors with a narrow beam (these lamps are physically smaller than low-pressure sodium and hence more photometrically controllable, this is why they are generally considered better, it's primarily a size issue not a spectrum issue).

The evidence proves very conclusively that although older drivers have consistently poorer vision than younger drivers, their visual skills are perfectly adequate. In some cases macular degeneration can result in the sufferer being registered blind, but is usually not so serious. Unless he or she has a diagnosed visual condition such as glaucoma, cataracts, diabetic retinopathy, a driver of any age is visually competent for the task. This area of research was resolved long ago and is no longer a subject of debate, and there's certainly no basis for blanket disqualification of drivers over 65. Although given the prevalence of visual conditions in these drivers, it would be prudent to require eye tests every couple of years.

_________________
http://www.itsyourduty.org.uk

Sorry to go off on a tangent a bit, but so I can learn from more experienced drivers, could you give me a couple of examples of when you have had to do this, or at least hypothetical examples of when you would do this.

I can think of three within the last few years.

* A shadow ahead that might have been a pedestrian, but turned out to be nothing more than a shadow.

* An unlit car that pulled out of a side road ahead. I don't know what I saw before I flicked the mainbeams on, but there it was and I had plenty of time to slow down.

* Sudden uncertainty about "where the road goes" in a set of roadworks. They have put up cones and keep left signs, but the keep left signs are wrong. I have to pass to the right of them. I need the extra light to understand this.

_________________
Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety