Can I just check I get the logic on which
temporary traffic lights work

1) they are usually installed where one
end of a road working cannot be seen
from the other

2) as well as preventing RTCs between
vehicles en route, they are also designed
to maximise maintenance crew safety

3) as such they tend to show RED (or STOP)
at both ends by default - i.e., when there is
no traffic on the stretch of road on which
work is being done - and turn to GREEN
(or GO) on a first-come-first-served basis
when the all sensors in play have established
it is probably safe for Road Traffic to pass.

G DAEB
COPYRIGHT (C) 2008 SIPSTON
--

On Aug 7, 10:24 am, FCS my-deja.com> wrote:

From what I've seen most of them are just on dumb timers with no
sensors whatsoever and take no account of different traffic flows in
the different directions.

Err, yeah.

B2003

FCS wrote:

No. There's 4 sets near where my brother lives, all on dead straight roads.
None of the works are more than 100yds long.

No. Most of them seem to be placed by pikey roadbuilders with no concern for
themselves or other traffic.

"FCS" my-deja.com> wrote in message
news:9ecf28d4-f3cc-42a0-be52-1ef964dec95e@34g2000hsf.googlegroups.com...

The choice of traffic control depends upon the length of obstruction and the
maximum two-way traffic flow of the unobstructed road. For example, a flow
rate of 1400 vehicles per hour over a 100m obstruction would permit the use
of Stop / Go boards, but greater values would require traffic lights. They
are also normally only used when the expected duration of the works are long
enough to justify the effort needed to carry out the installation of the
lights. Works of more than 300m in length should not have lights installed
without the approval of the Highways Authority.

"nightjar .me.uk>" wrote in message
news:Z7SdnbYVg4GOswbVnZ2dnUVZ8v6dnZ2d@giganews.com...

Ah! Maybe that explains the bizarre behaviour of the permanent lights on the
bridge over the Thames near me. The lights are about 1/10 mile apart, with
several bridges across the navigable and over-the-weir branches of the river
in between. They are activated by sensors on the approach, with several keep
alive sensors on the bridges themselves to detect traffic which has passed
the entry set of traffic lights but which is taking longer than normal to
cross.

Many times I have approached late at night and seen the green light turn to
red just as I get there. And yet no oncoming cars come over the bridge and
there is nothing at the other end which could have triggered the lights to
change.

"Mortimer" privacy.net> wrote in message
news:ofqdndUxSfKtrgbVnZ2dnUVZ8vydnZ2d@posted.plusnet...

On 8 Aug, 00:15, "nightjar" .me.uk>
wrote:

They tend to work to the rules though without using their brains much.
Some temp lights near my mums place last year caused endless traffic
jams. One of the pikeys forgot to top up the generator over the w/e
and the lights went out. The queues vanished. Quelle surprise.

For some reason beaurocrats just won't believe that drivers can
frequently do better at on the stop traffic control than their
overpaid consultants and expensive schemes. We've probably all driven
though places where fixed lights have died and marvelled at how freely
the traffic was flowing compared to normal.

B2003

On Thu, 7 Aug 2008 10:24:41 +0100, FCS wrote
(in article
<9ecf28d4-f3cc-42a0-be52-1ef964dec95e@34g2000hsf.googlegroups.com>):

As nightjar has already said, they *should* be set for vehicle activation -
which means that on quiet roads they will spend a lot of time with both ends
of red. When a car approaches, that end will immediately turn green because
the system doesn't need to wait for the other end to turn red etc. For simple
two way lights, there are two timers that can be adjusted - one sets the
maximum length of a green signal in each direction, the other sets the
duration of all red (ie both ends are red while traffic clears the works
before the other flow begins).

"Boltar" yahoo.co.uk> wrote in message
news:ddc1a399-ded0-48e9-8d51-2a6c221b45e5@a70g2000hsh.googlegroups.com...

I would be surprised if the same applied during the weekday rush-hours,
which is what the lights system would have been designed to suit.

Colin Bignell

"nightjar .me.uk>" wrote in message
news:JYydnSrhe-S2nALVnZ2dnUVZ8uednZ2d@giganews.com...

So operate the lights during the weekend rush, and turn them off the rest of
time. Joe Public saves twice over - the fuel bill for the lights is reduced
(i.e. the contract price for the project is lower) and the direct cost to ...