"Iain" wrote in message
...
(Richard M Willis) wrote in
m:

As I understand it, you DO have to stop if the
filter isn't showing in one situation: if the filter
light is to the immediate left or right of
the main light, rather than underneath it.

I was led to believe that the law regarding
filter arrows is thus:

* If the filter arrow is below the main green light,
then if the main light is illuminated but the filter
isn't, you may proceed across the stop line
and wait to turn when it is safe to do so.
Once the filter arrow illuminates you can
assume it IS safe to do so as the oncoming
traffic will now be on a red.

* If the filter arrow is beside the main green light,
then if the main light is illuminated but the filter
isn't, you must not cross the stop line, even if
it is safe to turn. You must wait for the filter to
illuminate before you can even begin to make
the turn.

I'm sorry, but I think this is not correct. When TPTB want all right-turning
traffic to wait regardless of oncoming flows, they use a red light with a
forward green filter (and a left filter as well if necessary). Perhaps this
is the scenario where your friend failed his test (described below.)

IME right filter lights are only beneath the other lights when on a traffic
island which is very narrow.

Interestingly enough I can't find anything in the
Highway Code to back up this belief, despite
the fact that a few years back a friend failed
his car test and the examiner told him that
one of the faults was to
edge forward at a beside-the-main-light filter.

--
John Rowland - Spamtrapped
Transport Plans for the London Area, updated 2001
http://www.geocities.com/Athens/Acro...69/tpftla.html
A man's vehicle is a symbol of his manhood.
That's why my vehicle's the Piccadilly Line -
It's the size of a county and it comes every two and a half minutes

"Peter Beale" wrote in message
o.uk...
In article ,
(Jeremy Parker) wrote:

Try Massachusetts. You too can drive like a Bostonian.

Just spent two weeks in MA, during which I came across
about three "rotaries". Anyone going to Boston is
well-advised to park on the edge and take the "T".
The "Big Dig" is coming to its completion, but
some way to go yet!

One thing which struck me as very odd (apart from
driving on the wrong side of the road) was a number
of quite major cross-roads where traffic from all four
directions is required to stop. They then look at each
other until one of them decides to proceed,
hoping that the other will not do so at the same time.

There is a four-way stop sign here in London - at the junction of Elgood
Avenue and Gatehill Road, in Northwood (HA6). Both roads are private.

--
John Rowland - Spamtrapped
Transport Plans for the London Area, updated 2001
http://www.geocities.com/Athens/Acro...69/tpftla.html
A man's vehicle is a symbol of his manhood.
That's why my vehicle's the Piccadilly Line -
It's the size of a county and it comes every two and a half minutes

"Richard M Willis" wrote in message
om...
"mookie89" wrote in message news:IPkvc.5247

Also, our emergency vehicles have what's known as an OptiCon System on
board. Basically it is a very specific white high intensity strobe lamp
aimed slightly upward. At many USA intersections a little periscope
appearing apparatus is mounted just above the traffic light. That's the

Don't you get boy-racers, and other miscreants, attempting to
synthesize the correct light-frequency and thus give themselves priority
at junctions ?

We'd get that sort of thing here. My last job involved telemetry
via UHF radio. Other European countries apparently used it to
give emerg vehicles priority but it was apparently rejected for the
UK, because nefarious persuns would be able to defeat it, even when
we proposed a 200-years-to-break challenge-acknowledge protocol (it
was two-way) !

Yes, that happens once in a great while. However, the OpiCon utilizes an
extremely bright and distinctive strobe so the miscreant would be easily
identifiable. In my home town, I am not aware of anyone ever attempting to
"play the game" besides me, of course ;-)

Rich

In article , Iain
writes
The presence of this superfluous combination of signals causes far
too many
people to think that they must stop UNLESS they have a filter, i.e.
that
the solid green applies only to movements that don't have a filter
even
if that filter is currently dark.

As I understand it, you DO have to stop if the filter isn't showing in
one situation: if the filter light is to the immediate left or right of
the main light, rather than underneath it.

Not so.

I was led to believe that the law regarding filter arrows is thus:

Here's what the law actually says:

====
Significance of light signals prescribed by regulations 33 to 35

36. - (1) The significance of the light signals prescribed by
regulations 33, 34 and 35 shall be as follows -

(a) subject to sub-paragraph (b) and, where the red signal is shown at
the same time as the green arrow signal, to sub-paragraphs (f) and (g),
the red signal shall convey the prohibition that vehicular traffic shall
not proceed beyond the stop line;

(b) when a vehicle is being used for fire brigade, ambulance, bomb or
explosive disposal, national blood service or police purposes and the
observance of the prohibition conveyed by the red signal in accordance
with sub-paragraph (a) would be likely to hinder the use of that vehicle
for the purpose for which it is being used, then sub-paragraph (a) shall
not apply to the vehicle, and the red signal shall convey the
prohibition that that vehicle shall not proceed beyond the stop line in
a manner or at a time likely to endanger any person or to cause the
driver of any vehicle proceeding in accordance with the indications of
light signals operating in association with the signals displaying the
red signal to change its speed or course in order to avoid an accident;

(c) the red-with-amber signal shall, subject in a case where it is
displayed at the same time as the green arrow signal to sub-paragraph
(f), denote an impending change to green or a green arrow in the
indication given by the signals but shall convey the same prohibition as
the red signal;

(d) the green signal shall indicate that vehicular traffic may proceed
beyond the stop line and proceed straight on or to the left or to the
right;

(e) the amber signal shall, when shown alone, convey the same
prohibition as the red signal, except that, as respects any vehicle
which is so close to the stop line that it cannot safely be stopped
without proceeding beyond the stop line, it shall convey the same
indication as the green signal or green arrow signal which was shown
immediately before it;

(f) save as provided in sub-paragraphs (g) and (h), the green arrow
signal shall indicate that vehicular traffic may, notwithstanding any
other indication given by the signals, proceed beyond the stop line only
in the direction indicated by the arrow for the purpose of proceeding in
that direction through the junction controlled by those signals;

(g) where more than one green arrow is affixed to light signals in
accordance with regulation 34(1)(b), vehicular traffic, notwithstanding
any other indication given by the signals, may proceed beyond the stop
line only in the direction indicated by any one of the green arrows for
the purpose of proceeding in that direction through the junction
controlled by those signals; and

(h) where the green arrow signal is displayed at the same time as the
green signal, vehicular traffic may proceed in the direction indicated
by the green arrow in accordance with sub-paragraph (g) or in any other
direction in accordance with sub-paragraph (d).

(2) Vehicular traffic proceeding beyond a stop line in accordance with
paragraph (1) shall proceed with due regard to the safety of other road
users and subject to any direction given by a constable in uniform or a
traffic warden or to any other applicable prohibition or restriction.

(3) In this regulation the expressions "vehicle" and "vehicular traffic"
do not include tramcars.
====

Note that there is *nothing* about the relative arrangement of the lamps
that aren't lit.

Summarising:
* Green arrows authorise movement in the indicated direction(s), whether
or not a red light is show.
* Green lights authorise movement in all directions.
* Green light plus green arrows indicate both.

Separately from this, my understanding of the other rules for lights is:
* A green arrow may only be extinguished when:
- an amber light comes on, or
- red+amber lights change to green light
on the relevant signal.
* Green light plus green arrow means that traffic turning in the
direction of the arrow does *not* need to worry about conflicting
movements.

Other regulations do talk about the arrangement of lamps.

* If there is a green lamp, one or two arrows or tramcar signals may be
placed on one side but not both sides. Arrows on the left must be
upwards or leftwards; those on the right must be upwards or rightwards.
The first arrow or sole tramcar signal must be beside the green; the
second arrow goes above it. If there are two arrows, the one nearest to
pointing upwards must be at the top; a tramcar signal goes above the
arrow, not below.

R R R R R R R R
A A A A ^A A^ TA AT
G G TG GT G G G G

* If there is no green lamp, then its place must be taken by a green
arrow. Another arrow or a tramcar signal may be placed on its left or
right side (but not both); if there is another arrow, a tramcar signal
may be placed above it, next to the amber. If there are two arrows, they
must differ by at least 45 degrees; the left of the two must not point
right of vertical while the right one of the two must not point left of
vertical, and the order must be "natural".

R R R R R
A A A A TA and similar on the right
^ T ^ ^

--
Clive D.W. Feather | Home:
Tel: +44 20 8495 6138 (work) | Web: http://www.davros.org
Fax: +44 870 051 9937 | Work:
Please reply to the Reply-To address, which is:

In article , Mark Brader
writes
Perhaps the most common
way this is used is for straight-ahead traffic to have a red light in
all directions, while left turns in both directions from one of the two
streets have a green left arrow;
[...]
I haven't driven enough in British cities to know whether the mirror-
image of this is a common pattern there.

I wouldn't call it "common", but it's not that unusual.

In North America, the combination of a green left arrow and an ordinary
green means that all moves are permitted, but the left turn is protected.

The mirror image statement is true here.

(Other meanings of
flashing green exist in other places, notably the province of British
Columbia.)

Do tell.

--
Clive D.W. Feather | Home:
Tel: +44 20 8495 6138 (work) | Web: http://www.davros.org
Fax: +44 870 051 9937 | Work:
Please reply to the Reply-To address, which is:

Mark Brader:
(Other meanings of flashing green exist in other places, notably
the province of British Columbia.)

Clive Feather:
Do tell.

Off-topic. See http://www.roadfan.com/mtrfaq.html#110.

ObOn-topic version: indicates that none of the next *four* signals is red,
intended to authorize speeds above 125 mph...
--
Mark Brader "It is considered a sign of great {winnitude}
Toronto when your Obs are more interesting than other
people's whole postings." --Eric Raymond

My text in this article is in the public domain.

In article ,
Mark Brader wrote:
Off-topic. See http://www.roadfan.com/mtrfaq.html#110.

ObOn-topic version: indicates that none of the next *four* signals is red,
intended to authorize speeds above 125 mph...

You got me there

Nick, envisaging doing 125mph down the Euston Road if you get a flashing green
--
"My objective at this stage was to work about 3 days per week"
-- Richard Parker in http://web.ukonline.co.uk/richard/cv78.html

"Mark Brader" wrote in message
...
Mark Brader:
(Other meanings of flashing green exist in other
places, notably the province of British Columbia.)

Clive Feather:
Do tell.

Off-topic. See http://www.roadfan.com/mtrfaq.html#110.

ObOn-topic version: indicates that none of the next *four*
signals is red, intended to authorize speeds above 125 mph...

Why would speeds above 125mph be on-topic in uk.transport.london? ;-)

--
John Rowland - Spamtrapped
Transport Plans for the London Area, updated 2001
http://www.geocities.com/Athens/Acro...69/tpftla.html
A man's vehicle is a symbol of his manhood.
That's why my vehicle's the Piccadilly Line -
It's the size of a county and it comes every two and a half minutes

John Rowland wrote:
"Mark Brader" wrote in message
...
Mark Brader:
(Other meanings of flashing green exist in other
places, notably the province of British Columbia.)

Clive Feather:
Do tell.

Off-topic. See http://www.roadfan.com/mtrfaq.html#110.

ObOn-topic version: indicates that none of the next *four*
signals is red, intended to authorize speeds above 125 mph...

Why would speeds above 125mph be on-topic in uk.transport.london?
;-)

You should know, John. Your vehicle (according to your sig) serves a
place that sees speeds above 125mph every minute or so of the day.
;-)
--
Richard J.
(to e-mail me, swap uk and yon in address)

In article , Mark Brader
writes
Mark Brader:
(Other meanings of flashing green exist in other places, notably
the province of British Columbia.)

ObOn-topic version: indicates that none of the next *four* signals is red,
intended to authorize speeds above 125 mph...

Next *three*; the fourth can be red: FG, G, YY, Y, R.

--
Clive D.W. Feather | Home:
Tel: +44 20 8495 6138 (work) | Web: http://www.davros.org
Fax: +44 870 051 9937 | Work:
Please reply to the Reply-To address, which is: