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A question about the traffic lights:

I've noticed that some lights have a board with a white lining on its edges,
whereas others do not.

What's that about?

Constant anouncements on London Buses
 

Constant anouncements on London Buses
 

"Richard J." wrote in message
om...
wrote:
A question about the traffic lights:

I've noticed that some lights have a board with a white lining on its
edges, whereas others do not.

What's that about?

It was a design of traffic light introduced years ago, presumably in order
to make them easier to see. Evidently it wasn't found particularly
useful, as the requirement for the white-edged board was withdrawn. But
some lights still have them. They have no legal significance compared to
other traffic lights.
--
Richard J.
(to email me, swap 'uk' and 'yon' in address)
I see. I was just wondering if it meant that some could be manually
controlled, while others were completely on time automation.

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On Sat, 29 Nov 2008 14:14:37 -0000, wrote:

I see. I was just wondering if it meant that some could be manually
controlled, while others were completely on time automation.

A lot more lights have them outside London than in it. Why has London
always been different? (Other than that a narrow bodied traffic light
with no border has always had a very distinctive London look to me).

Neil

--
Neil Williams
Put my first name before the at to reply.

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Neil Williams wrote:
On Sat, 29 Nov 2008 14:14:37 -0000, wrote:

I see. I was just wondering if it meant that some could be manually
controlled, while others were completely on time automation.

A lot more lights have them outside London than in it. Why has London
always been different? (Other than that a narrow bodied traffic light
with no border has always had a very distinctive London look to me).

Before 1965, all posts carrying road signs were painted in alternating black
and white bands. On traffic lights, the black and white stripes extended to
the light units themselves, the red and green units were black and the amber
unit was white. When the new road signs were introduced in 1965, all posts
became grey, and I think it was then that the black backing board and thick
white border were introduced. I assume that it wasn't necessary to retrofit
the boards to old traffic lights.
(Illustration at http://www.igg.org.uk/gansg/00-app1/tlight.jpg )

Probably London's roads were more densely populated with traffic lights than
the rest of the country, and hence (I'm guessing here) for some years the
majority of new traffic lights were installed outside London. But the
boards made the whole assembly much wider than previously, and caused
problems at constricted sites. Hence the boards are now optional, as are
the white borders.
--
Richard J.
(to email me, swap 'uk' and 'yon' in address)

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On Nov 29, 7:52*pm, "Richard J." wrote:
Neil Williams wrote:
On Sat, 29 Nov 2008 14:14:37 -0000, wrote:


A lot more lights have them outside London than in it. *Why has London
always been different? *(Other than that a narrow bodied traffic light
with no border has always had a very distinctive London look to me).

Before 1965, all posts carrying road signs were painted in alternating black
and white bands. *On traffic lights, the black and white stripes extended to
the light units themselves, the red and green units were black and the amber
unit was white. *When the new road signs were introduced in 1965, all posts
became grey, and I think it was then that the black backing board and thick
white border were introduced. *I assume that it wasn't necessary to retrofit
the boards to old traffic lights.
(Illustration athttp://www.igg.org.uk/gansg/00-app1/tlight.jpg)

Probably London's roads were more densely populated with traffic lights than
the rest of the country, and hence (I'm guessing here) for some years the
majority of new traffic lights were installed outside London. *But the
boards made the whole assembly much wider than previously, and caused
problems at constricted sites. *Hence the boards are now optional, as are
the white borders.
--
Richard J.
(to email me, swap 'uk' and 'yon' in address)

The original purpose of the boards was to provide a background against
which the signal stood out. When viewed against the sky it was often
difficult to see which aspect was illuminated, together with
increasing street clutter. The boards started being dispensed with in
London when new signal heads were introduced that were much brighter
during the day (and even LEDs in some cases) and adjusted to be less
bright at night. The boards, which were always a maintenance
nightmare, coming loose or being hit by vehicles, were considered
unnecessary in view of the increased visibilty of the new aspects.

Maybe London has more of these lights than elsewhere in the country,
so the boards are still more prevalent outside the Capital.

Peter

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In article ,
(Richard J.) wrote:

Neil Williams wrote:
On Sat, 29 Nov 2008 14:14:37 -0000, wrote:

I see. I was just wondering if it meant that some could be manually
controlled, while others were completely on time automation.

A lot more lights have them outside London than in it. Why has London
always been different? (Other than that a narrow bodied traffic light
with no border has always had a very distinctive London look to me).

Before 1965, all posts carrying road signs were painted in
alternating black and white bands. On traffic lights, the black
and white stripes extended to the light units themselves, the red
and green units were black and the amber unit was white. When the
new road signs were introduced in 1965, all posts became grey, and
I think it was then that the black backing board and thick white
border were introduced. I assume that it wasn't necessary to
retrofit the boards to old traffic lights.
(Illustration at http://www.igg.org.uk/gansg/00-app1/tlight.jpg )

Probably London's roads were more densely populated with traffic
lights than the rest of the country, and hence (I'm guessing here)
for some years the majority of new traffic lights were installed
outside London. But the boards made the whole assembly much wider
than previously, and caused problems at constricted sites. Hence
the boards are now optional, as are the white borders.

I don't think back boards go back anywhere near 1965. They came in no
earlier than the 1980s IIRC.

--
Colin Rosenstiel