Why street lights on all night?

[Owain]

This was done in the 1930s- when street lights were wired for full/half circuits.

Owain

[Jules]

It's people coming 'blind' out of side roads who have no ability for judging the speed of through-traffic who can cause real messes in situations like that, though.

50ft? More like 15... :(

[nightjar]

That was when I was in the electricity supply industry. The usual arrangement was a single timer in the local substation, operating a separate sub main to run the street lights.

Colin Bignell

[clumsy bastard]

how do you do that?

[clumsy bastard]

ahh, you already answered. How do you avoid low hanging tree branch or a hole. Would any of the above have half a chance in a wind?

[clumsy bastard]

you will be on dipped in my scenario, like 99% of motorway traffic, unless you are dazzling everybody. Dipped range is?

(and not everything solid is bright)

"expects" is a good word. Not everything that turns up in a carriageway has reflectors, including crashed cars sideways on. Ladders fallen off vans (seen that) cows (heard of that often) or drunks.

[clumsy bastard]

I didnt say other traffic hazards were not available.

If you cannot stop within the distance you can see you are not driving within your competence, you are just relying on the probability that the road is clear. That *should* be pretty scary but isn't, we just assume its clear.

I didn't in any case say anything about 3am, it gets dark soon after

4pm at the moment. A typical situation is 6pm, all cars on dipped because there is plenty of traffic in both directions, everybody is just following everybody else's tail lights, when there is a gap ahead of a bunch of cars they are heading into blackness at 70+ mph on dipped.............. Would you be willing to walk out into the middle lane of a dark motorway and see if when the traffic came it saw you and stopped?

[Rod]

I fully agree that it is possible to walk in very dark places reasonably safely. But nonetheless I would always carry a torch for the unexpected such as dog mess on pavements.

[Huge]

Dunno. That's the answer I got when I asked why PA roads have no catseyes...

[The Natural Philosopher]

Not many of those on motorways..

[The Natural Philosopher]

use all the senses you have.

When you have to walk dogs at night you discover that they, equipped with ears and noses - manage perfectly ell, rushing all over the place.

[The Natural Philosopher]

Tree branches are bad. I hold a hand in front of my eyes.

Wind is also not so good. Yes, it tells you where the leaves are..but masks everything.

it even screws up wildlife. I managed to shoot a pigeon with an air rifle in a gale once. It didn't hear me coming.

[The Natural Philosopher]

I wa on my own at the time..

Dipped takes ou down to at best 400 yards.

BUT if there is other traffic around, THEIR lights pick up the obstacles etc.

And thats the same in bright daylight too.

shed loads and bits of car parts.. if a wheel comes barreling at 70mph plus and hops the barrier, you have very little chance of doing anything.

There is no safe speed. Not even zero, on a motorway. You are playing the percentages every time you turn the ignition on.

[The Natural Philosopher]

then 100% of the drivers on the road are driving outside their competence.

This is a silly rule for stupid people.

You cannot know that a mile of clear road that you can see, will not suddenly become less clear 3 ft in front of your bonnet.

Deer are an especial hazard round here.

In towns, it's pedestrians.

Or people pulling out of sie roads.

On a motorway, people rely on the fact that there are no pedestrians side roads or deer. AND the fact that te car in front ant stop instantaneously either.

BUT that doesn't take into account stuff falling off traffic in front, or the car that comes over the crash barer from the oer lane. or a few other instances.

All of which are in fact FAR more probable than a black car sideways on with no one waving a torch.

70mph dipped is not a problem.

Nope. I assume they assume no one would be such a dick.

[clumsy bastard]

they have much better smell, hearing? Not sure. I reckon their eyes are good in the dark too. I would like to see a human demonstrate it in the *pitch* black you suggest. I find that on a moonless overcast night in a wood its just plain impossible.

[clumsy bastard]

or mineshafts on the cornish moors

[clumsy bastard]

cats are not keen on going out in wind.

[clumsy bastard]

that was my point.

Really?

you raised a mile, I would say your stopping distance (not double that unless you dont think its fair to assume no oncoming traffic, a small risk, but one you don't discount below). There is always additional risk from suddenly appearing objects from the side and we *additionally* modify our speed for lack of sideways visibility, like passing a parked car that may conceal a child.

So, generally we drive at speed to stop in half the distance we can see *and* make speed allowance for the possibility of objects emerging from the side.

Yes, they do. That was my point. Unfortunately sometimes there are such objects and cars do stop instantly when they hit a pile of other cars/drivers who made the same wrong assumptions.

all of them are perfectly probable and usually cause pile ups. Watch the videos on youtube!

why not, if 70mph on dipped isn't a problem? You know as well as I the cars would hit you because they cant see properly.

[clumsy bastard]

I'm talking generally

which is the real life normal situation

Yes, but my point is what happens when you find yourself the lead car with a gap ahead

in daylight you can see beyond your stopping distance, at night you cannot, so its not the same.

Of course, but is that a reason for driving badly generally?

Of course not. Particularly on a motorway at night where half the drivers would hit your stationary vehicle, but there is a *reasonably* safe speed, I would say its probably 90-100 in good daylight conditions and 50 at night on dipped.

But it seems to me we make the wrong calculation on Mways at night out of complacency. After all, the impact will probably be fatal.

[clumsy bastard]

can I clarify? The point I am making is that most people think they can see to stop on the motorway at night when in fact the reason they dont crash is the low likelihood of there being anything to hit. When at the front of a group of traffic at night on dipped at 70+, they think they are driving on eyesight observation, they are actually driving on the gamble motorways are usually clear.