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Wednesday, 07 November 2018


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I guess if the signs said "No Fog Lines for the Next nn Miles" folks wouldn't know what they are talking about. The signs around these parts (SW Ohio) say "No Edge Lines"

Did you know about Botts dots?

From Wikipedia: "Botts' dots may also be called turtles (Washington and Oregon) or buttons (Texas and other southern states). In many parts of the US and other countries, Botts' dots are used, along with reflective raised pavement markers, to mark lanes on highways and arterial roads."

Here in Boston those Fog Lines are called "just ignore them they're not important for anything" lines.

Here in Israel the fog lines are yellow and the middle line is white.

Pretty sure that the lines at the edge of (major) roads are not called 'fog lines' in the UK at least. Also pretty sure that fog lights are much more general than that: their purpose is to illuminate the road close to the front of the car in general, since that's the only part if the road you can see in fog (brighter headlights just mean you see brighter scattered light from the fog). Fog lights are useful in fog regardless of whether there are markings or not on the road.

Remember when the fog lines weren't all that common? I struggle more than most, I think, to see in the dark, and so when those white lines started going in on even the most rural paved roads it was a real godsend. I follow them religiously when I drive at night.

I once got hired to research the history of pavement markings for movies because different localities have different pavement markings and they keep changing about every ten years. The Texas DOT is a great resource BTW.

Anyway the history of Dr. Dorr and fog lines is really interesting and is often cited in articles in favor of less regulation of private philanthropic foundations. https://cspcs.sanford.duke.edu/sites/default/files/descriptive/preventing_crashes_on_americas_highways.pdf

My sister-in-law once had to switch the yellow and white lines on a one way mountain road for a car commercial where the director wanted to have the car going down the uphill section of road and it took six miles of yellow and white gaffer tape.

Uh-huh. Learned about fog lines a few years back when a car load of us got stopped by the local police for straying over the fog line more than once. Evidently that implies you may be impaired in some way and gives them good reason to intervene.

Maybe they should be called "fog line lights". Since you can't turn off your headlights, they truly are next to worthless in dense fog.

And then there's the question of why everyone drives with their fog line lights on during the day, too.

oh, forgot this

I did know the side white lines were "fog lines" but I didn't know that you drove on the left in your part of the world.
(tip: a quick lateral flip in Photoshop could fix that!).

Talking of fog and driving in it, I wonder if you have what we in the U.K. called 'cat's eyes' ? In case you wonder what on earth I am talking about I should perhaps explain that they were an invention that consisted of a square rubber type shoe which was I think fitted into a metal frame and fitted into the highway along the centre line at intervals, it would be a white line in our case, but yellow over there. Within the rubber shoe would be fitted 4 glass balls like marbles, two on each edge facing the direction of traffic. These glass reflectors picked up the headlights of cars and were very bright. The great thing was that they were self cleaning by design, as traffic drove over them the rubber acted like an eyelid blinking over an eye does, they rainwater stored inside the rubber shoe was used. They did indeed look like cat's eyes might when reflecting a car headlight. In fog they made a massive difference to seeing where the road was, and even in clear weather they allowed you to see the path of the road for huge distances on full beam. More recently they are fitting presumably less expensive reflectors on the road, made from plastic. They also have coloured cat's eyes to use on edges of the road and other fancy stuff.

The patent of the cat's eyes made the inventor, Percy Shaw, a great deal of money, but his real legacy is the countless lives that were saved by his invention.

Interesting. Many years ago my family took a vacation on Skyline Drive in the Blue Ridge mountains of Virginia. Got up in the morning and were totally fogged in. Visibility maybe ten feet. Asked what to do. The rangers said "There's a yellow line down the middle of the road all the way down. Just go slow and follow it." So they were proposing that as the fog line.

That's a new take on fog lamps. I fondly imagined they were to alert oncoming vehicles without having to use headlamps that, in fog, create as much interference with vision as the fog itself, creating a whiteout, like bouncing around as if within a cosmic softbox

A better alternative, probably impossible in many cities today, is this: follow the tramlines. Served me well in the grim days of 50s and 60s Glaswegian industrial smog. Those yellow streetlamps that were introduced at some stage helped too, but then the French knew all about that ages earlier, hence their traditional yellowed headlamps.

There's just got to be a photographic relevance there if we can concentrate long enough to find it... street safelights without need for papers and chemicals? Atavistic thinking, I suppose, what with all their historical photographic background.

Mike, I think you northern New Yorkers have a different definition. Here in Mississippi, fog lights are to be used on all gorgeous clear nights in order to temporarily blind oncoming motorists. And on gloomy, murky, misty mornings, fog lights (or any lights) are not used at all. I used to decry daytime running lights as just another manifestation of the nanny state. But I have changed my opinion; most Americans are such utterly inept thinkers about the mechanics of driving, we do need DRLs.

And all this time, I thought fog lights were provided specifically to help you ruin the night vision of other drivers by leaving them on all the freakin' time no matter how clear the weather.

Having lived in fog-bound areas - um - yes, I knew that. The lines now have an additional advantage, as they can be read by the cameras on cars with self steering functions, "lane assist" and the like.

You’re right about fog lines, but I haven’t found corresponding confirmation regarding the direct relationship to fog lamps.. My brief search generally indicates that front fog lamps are designed to illuminate the road and any close hazards in fog, not specifically the fog line. Can you provide a source?

On a related note, fog lamps are apparently disappearing...

And In Europe, rear fog lights are mandatory. These obviously are designed to help drivers following closely behind.

Educate me...Fog is white.The painted,”fog lines”are also white.How does this work practically ?

About 40% of drivers have their fog lights on as a matter of course when it gets dark. I’m completely mystified as to why this is! Now if ya can answer me that...

I like to drive with my fog lights always on. I find that extra bit of illumination, especially to the sides, helpful to my aging eyes. One night, a CHP officer pulled me over and told me it is illegal to drive in California with fog lights on when there is no fog. I said, sorry, I didn't know. Later, I checked the CA DMV regulations. Turns out the officer was wrong. You can drive with your fog lights on, as long as you have your high beams off. The rule is max 4 forward lights.

oddly, I just learned they are called fog lines this afternoon. Who would have thought?

Yeah, fog lines & lights, for those of us with a “attention deficit” issue?


Fog lights were also helpful in the days when you could turn them on but keep your headlights or daytime running lights off. Those lights are higher up, and the light from them is more likely to reflect back into your eyes, making it harder to see through the fog. The fog lights, being lower, reflect light up above the roof of your car, giving you better visibility.

Fog lights are nearly useless in that regard when combined with headlights/DRLs, as opposed to instead of them, but we can thank lawmakers for that. I got it around it in my old car by popping the hood and unplugging the harnesses from the headlight bulbs, and in my new car thanks to some tricky re-programming of the car's computer through a laptop and software from a clever Russian hacker!

Sorry. Front foglights are automotive jewellery. Over used and a pita when people try to adjust them for distance and only blind oncoming traffic. The spawn of the devil.

I remember a thought occurring to me when at university, late one night, after some chemical ehancememt. Surely at some point in time it must have been possible for a single human being to know all academic knowledge, simply because there was so little of it. Say around the time of the early Library of Alexandria - as a random pluck from one’s orifice.
When you think about the shear volume of human research today and knowledge about the universe around us, and about how humans can manipulate materials within this universe, no one individual can ever hope to barely scratch the surface of the sum total of current human knowledge - let alone scratch the surface of viewing the volume of photos produced every day, or properly scratch that GAS itch ;~)
Phew, I think I need another wine after that.

I experienced this first hand several years ago on a trip along the Blue Ridge Parkway beginning at Cherokee and driving North. It was so foggy you could barely see past the hood of the car. The white lines served as our only guide. On occasion there were long gaps in the white lines at scenic overlooks and side roads, made one temporarily think they had driven off the road and gone over the edge.

In parts of California where winter fog can be a killer weather condition, three raised reflective markers are placed on the right shoulder 2,100 feet from a freeway exit. Two markers at 1,400 feet and one marker at 700 feet. After the final marker, drivers can look for the white fog line on the shoulder to veer right along the exit ramp. I don't know if this is a California only or a federal design.

The fog that affects the 400 mile long California central valley is Tule fog, which comes from wet ground and still weather conditions. When I was a boy, when cavemen drove yabba yabba do cars, thick dense tule fog was the biggest cause of vehicle accidents. Fog and idiot drivers who didn't slow down. There were many reports of multiple car accidents involving 30-40 cars. In my lifetime, because of changing weather, tule fog is now much less of a problem for drivers but an increasing problem for farmers whose trees need the cold air of fog to "rest" for the growing season.

More generally, fog lights brighten up a wider field of view of the roadway to the side and to the front. If you live in the country and are looking for a narrow side road to turn into, having fog lights on a misty/foggy evening makes it easier to spot the break in the shoulder where the road is. This is especially helpful on gravel roads where there are no painted lines. Came in handy a few times when I was rallying.

In some places (example: California) they may be known as fog lines, but to most traffic engineers, they are edge lines.

As to the lights on my Ford Flex, they don’t reach out far enough to provide useful retroreflectovity with reflectorized edge lines. I think they are jes fo sho, as they say.

Can you guess what I do for a living?

A colleague came into my office asking what fog lines were! Luckily I'd read this and knew the answer. thanks!

True fog lights are mounted as close to the pavement as possible to provide light under the fog layer, and are nearly useless if the headlights are also on.

The "fog" lights on today's cars are utterly bogus, and just cause problems for oncoming drivers. Turn 'em off!!

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