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Comment by bjackman | Hacker News Reader

Going to have to be cynical about this. What problem does this solve? Cats-eyes[1] do a very good job the world over at the moment.

[1] http://en.wikipedia.org/wiki/Cat%27s_eye_%28road%29

edit: Now I think about it, that Wikipedia article makes it sound like Cats-eyes are mainly a UK thing. People in other countries - do you not have these?

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Glowing lines will show even where your headlights are not shining. Curves and intersecting streets come to mind. Even gaps in the line for a driveway would be apparent.

We have some reflectors, but the cost of installing snowplow survivable ones is high enough that they are not justified according to our highway department. (Missouri, USA, 38°N)

If the glow doesn't add too much to the cost of the paint, it could be a winner.

Yes, we have retroreflective road marking elements (meaning elements that try to send light directly back to the source) but they sometimes take a little different form.

Specifically, in California, we have plastic ones closely resembling the picture you linked, which are tarred to the road surface, but they have a corner cube molded plastic retroreflective element (like a bicycle reflector) instead of a spherical glass element. However, some signs still feature large diameter glass beads: http://www.aaroads.com/shields/show.php?image=CA19580103

Also, the road paint itself contains high-index glass spheroids that retroreflect headlights back into the driver's eyes, making the paint glow brighter than it would normally. Cat's eyes everywhere!

Actual cat eyes are also retroreflective due to the tapetum lucidum. http://en.wikipedia.org/wiki/Tapetum_lucidum

We don't have them in Canada because they prevent us from using snow plows on the road.

In my part of Canada we do. Or maybe I should say did... until the snow plows got them.

I live in Prince Edward Island and they were put in in some especially tricky areas just last summer and already they are mostly gone. They were the type where they cut a little dip in the road and install them so that they are even with the height of the pavement and that didn't even save them.

The glow in the dark paint on the other hand would be a huge improvement and not susceptible to damage. Not to mention no installation required.

Interesting.

The Gorge in OR has the sunken markers and I've yet to see one show up missing during the snow season.

Wonder if there is specific method to install and also for applying the snow plow to cause the reflectors to stay in place.

I don't know about the whole of PEI - I only lived in the Summerside area for a little over a year, or two winters' worth, before the Canadian Forces Base closure was announced - but in my experience snow was not anything like occasional (or vertical, for that matter; precipitation is a horizontal phenomenon) and ground stability is an old civil engineer's wife's tale. The island is essentially a waterlogged sandbar with a plastic surface that almost seems alive during the frost season. Shallow roadbeds ripple with the seasons; deep concrete slabs tend to shift significantly. (The slab-bed highway around Charlottetown looked like a post-earthquake scene in the spring of '89, and a brisk business was being done in tires, wheels and steering and suspension parts.) There isn't a lot that works well "everywhere" that's directly transferable to PEI. The only way to make sure that inset features stay inset is to sink them deep enough to be more or less useless.

In AZ, CA and OR (only states I know for sure) in the snowy areas, reflective markers are placed in a divot removed from the area between the painted lane markings. It works and is not very noticeable when changing lanes.

As soon as you get to the areas where snow is minimal, the divots stop.

I've not noticed other states (WY, CO, NE, KS) doing this.

They're present on some BC roads, where it doesn't snow as much.

We have them in Texas but I've never heard them called that. Growing up we just called them "city titties" but I doubt that is the technical term.

Yes, Florida (which gets massive amounts of rain) has them absolutely everywhere, from regular roads and avenues, to highways and turnpikes. They're the plastic version, not the metal snow plow survivable version. There's almost never snow down there anyway. Driving at night is amazing. The downside is that the roads are so nice people get a little too comfortable and relaxed when driving. So there's massive amounts of accidents and pedestrian hits and fatalities.

I drive a lot at night on I-70 between Denver and Green River. Visibility of the road is a big issue in the areas of tight curves. When I used to have an older car with weaker headlights having to step on brakes abruptly for not being able to tell which way the road ahead curves used to happen periodically.

Over the mountain passes in spring where the lane markings get worn down sometimes you just can't see anything w/o high beams (and risking to blind the oncoming traffic).

Most roads in the Netherlands have simple red or white reflectors every 50 meters or so alongside both roadsides, and/or in corners. Some areas have cat eyes, but that's very area-specific, not a national standard. Most roads have just white markings, which are only really visible when there's headlights on them - they become very hard to see when it's raining though. I don't know if these would solve that latter problem either.

Cat's eyes don't work with snow plows.

Wikipedia says different:

"Cat's eyes are particularly valuable in fog and are largely resistant to damage from snow ploughs."

http://en.wikipedia.org/wiki/Cat%27s_eye_(road)

As does the Reflecting Roadstud's manufacturer's website:

"The final component part of the “Catseye” is the cast iron base. Manufactured from Grey Iron, the cast iron base affords excellent protection to the rubber insert and has been specifically designed to withstand the demands of heavy traffic and effects of snow-ploughing."

http://www.percyshawcatseyes.com/products/the-cats-eyes-road...

The cat's eye will lift the plow off the ground and at that point the plow won't be doing its job. Not much snow in the UK.

Catseyes are a menace for bicycles so this would be great in urban areas, and especially dedicated bike tracks, eliminating the need for lighting.

how about these: https://upload.wikimedia.org/wikipedia/commons/b/b2/Leitpfos...

also road paint is mixed with glass fragments and is highly reflective. ok, it does not glow at night by itself, but your car should have lights ;)

It sounds like a UK thing because the inventor was Percy Shaw from Halifax in the UK. I went to school with his grand-daughter or something like that. Same as traffic lights were first used in the UK

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