Modern CFL Street lights really that efficient?

[EFLImpudence]

Just in case anyone thinks 183m is a strange figure for a statutory regulation, it is, of course, 200 yards.

 

[ekmdgrf]

http://www.youtube.com/watch?v=ZMvXODMD7EA

 

[AndrewDavie]

I hope they do replace those sodium lights. I hate them.
I _think_ the original idea was that orange lights are very visible.
The problem with that is while I can then see the streetlights very clearly, I have a very hard time seeing objects which may absorb that frequency of light rather than reflect it - feels like I'm seeing by moonlight/starlight, not much better than no streetlights at all.
So streetlights with a wide spectrum would be better (ie, white light) as that almost everything reflects some portion of white light and I'll be able to see them.

 

[JohnD]

the new ones are white. Even when they are not very powerful, it is like a bright moonlit might.

 

[EFLImpudence]

I think or rather it is thought the orange lights are better in the wet.

 

[ban-all-sheds]

When they first started lighting streets and highways well enough to be of use to drivers, what alternative lamp technologies were there?

 

[EFLImpudence]

Ah, good point. Lucky coincidence then.

Is it not correct?

 

[ban-all-sheds]

Dunno.

Might be as true as the French reasoning for having yellow headlights all those years.

But I think we had sodium lights because that was basically all that was suitable, and we kept them for as long as we did because of inertia and the cost of wholesale replacement.

 

[EFLImpudence]

You're not going to believe this but I've just been outside and they must have been round and replaced the street lights with LEDs (in Bournemouth for flameport).
We now have downlights with dark areas in between and the shadows are really dark.
The main road at the end of the street is totally bathed in a lovely orange glow.

I'll let you know what it's like when it rains.

 

[JohnW2]

Might be as true as the French reasoning for having yellow headlights all those years. ... But I think we had sodium lights because that was basically all that was suitable ....

As you say, it probably happened because there was no suitable alternative. However, if you want to look for a physiological rationale, IIRC, low-light-level human vision (using 'rods', rather than 'cones' in the retina) is most sensitive to the green/yellow part of the spectrum, and relatively insensitive to the blue part of the spectrum. Just a thought (even if it may well have been 'fortuitous'!)!

Kind REgards, John

 

[flameport]

Streetlights outside now (North Dorset), completely white, fairly wide angle of light output.

The light:

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View of road below, light is just out of frame at top left

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These have been in for a couple of years. Previously were cylindrical things on concrete posts, straight from the 1970s.

 

[bernardgreen]

You're not going to believe this but I've just been outside and they must have been round and replaced the street lights with LEDs

LED street lamps are being trialle my village, main advantage is lower running costs.

The main road at the end of the street is totally bathed in a lovely orange glow.

Changing the colour of street lightning at a junction or hazard was once used as an extre way to alert drivers of a need for more attention. I don't know it is was an official policy to do so or just a bit of common sense thinking by a few officers in a few local councils,

 

[ericmark]

One does wonder at the placing of some street lamps. Cul-de-sac by me has two foot paths at the end if light had been moved just 2 foot it would light them but it lights one but not the other as placed.

As to colour it was found that the sodium lamp colour allowed one to see better than the blue mercury as better suited to our eyes however they did not reflect from many of the hi-vis worn by workers I note the railway use a different colour for Hi-vis.

Lighting has always been complex but the law makes it even worse. I have noticed new poles just a little higher than the old ones I would guess old ones under the hight required by road traffic act when under 20 foot the distance between posts is about a 1/4 of the distance when over 20 foot high.

As to disused lamp posts I don't know. We have always had timers which switched of street lamps after midnight so I would think simply not being lit would not make a 30 MPH area unrestricted but I would think there is a time limit to repair broken lamps and if simply switched off it would raise the question did this mean the speed limit was also removed at the same time.

Flintshire has said they are putting 20 MPH speed limits outside every school but to do that means they also have to put in traffic calming which will cause problems on main roads. Also the lighting has to comply. Easy to fit signs it's the rest which causes the problem.

 

[ban-all-sheds]

As to disused lamp posts I don't know. We have always had timers which switched of street lamps after midnight so I would think simply not being lit would not make a 30 MPH area unrestricted but I would think there is a time limit to repair broken lamps and if simply switched off it would raise the question did this mean the speed limit was also removed at the same time.

That's an easy question to answer - nobody expects street lights to be on during the day, and nobody thinks that speed limits do not apply in the day.

I guess if you had the money to take a punt and you got done on a road where the street lights were never turned on, you could get a lawyer to argue that the road did not actually have “a system of street lighting furnished by means of lamps placed not more than 200 yards
apart”.

It's a bizarre regime anyway - it makes no sense that if a road's status is defined by the lighting that it's actually forbidden to have speed limit signs as well. If you were to design a system from scratch wouldn't you divorce the two? Use speed limit signs to indicate the speed limit, and lighting which was appropriate to the lighting needs.

Anyway - that's a digression within a digression.

Flintshire has said they are putting 20 MPH speed limits outside every school but to do that means they also have to put in traffic calming which will cause problems on main roads.

Traffic Advisory Leaflet 09/99 (20 mph Speed Limits and Zones) (DETR 1999a) gives advice on how and where to implement 20 mph speed limits and 20 mph zones. They should not be implemented on roads with a strategic function or on main traffic routes.

Also the lighting has to comply. Easy to fit signs it's the rest which causes the problem.

We have the technology to implement variable speed limits, so we don't, for example, have 20mph zones because of a school when there's nobody using the school, or where we do need them when the shops are open but between midnight and 5AM they could safely be 40mph, and to simultaneously ensure that if you break the speed limit you WILL get caught. It would require equipment in vehicles, but within a generation or less we could, if we wished, virtually eliminate speeding.

 

[ericmark]

Thank you for that reply.
BBC All schools in Flintshire to have 20mph zones outside is what I was looking at and Signing Requirements for Speed Limits it would seem the £50,000 is likely to be exceeded cost per hump at around £4,250 so each school will need at least 2 and around 70 schools I would say some one has missed at least one 0 off the figure quoted. And from what you say clearly not very well thought out.

At the moment there are signs with black instead of red outside some schools with no end of limit signs and there have been complaints that colour blind people can't tell if black or red.

Think some one got it wrong again dad!