The traffic lights here have three (traffic) phases:
1) turn right from the main road
2) forward or left from the main road
3) forward, left or right from the minor road
....in that order. Every other junction which I know has these three phases
has them in the opposite order.

Does anyone know why this junction is different?

In article , John Rowland
says...
The traffic lights here have three (traffic) phases:
1) turn right from the main road
2) forward or left from the main road
3) forward, left or right from the minor road
...in that order. Every other junction which I know has these three phases
has them in the opposite order.

Does anyone know why this junction is different?

I guess you don't go very far. I know of several sets OTTOMH within 12
miles that work the same.


--
Conor

I'm not prejudiced. I hate everyone equally.

Conor wrote:
In article , John Rowland
says...
The traffic lights here have three (traffic) phases:
1) turn right from the main road
2) forward or left from the main road
3) forward, left or right from the minor road
...in that order. Every other junction which I know has these three
phases has them in the opposite order.

Does anyone know why this junction is different?

I guess you don't go very far. I know of several sets OTTOMH within 12
miles that work the same.

Thanks. Can you think of anything else those junctions have in common which
might explain it?

"John Rowland" wrote in message
...
The traffic lights here have three (traffic) phases:
1) turn right from the main road
2) forward or left from the main road
3) forward, left or right from the minor road
...in that order. Every other junction which I know has these three phases
has them in the opposite order.

Does anyone know why this junction is different?

It is not different from several I know. This sequence would allow traffic
turning right from the main road to clear the area of the junction on the
minor road before that on the minor road needs to go straight ahead into it.
Depending upon the traffic volumes and any restrictions further down the
minor road, that could sometimes reduce the probability of crossing traffic
from the minor road obstructing straight ahead traffic on the main road.

Colin Bignell

In article , John Rowland
says...

Thanks. Can you think of anything else those junctions have in common which
might explain it?


Probably a traffic flow study.

--
Conor

I'm not prejudiced. I hate everyone equally.

"John Rowland" wrote in message
...
The traffic lights here have three (traffic) phases:
1) turn right from the main road
2) forward or left from the main road
3) forward, left or right from the minor road
...in that order. Every other junction which I know has these three phases
has them in the opposite order.

Does anyone know why this junction is different?


Looking at the junction on Google Maps the A10 is two lanes per direction
dual carriageway which expands at the junction to five lanes arranged left
to right as follows:

1 Left Turn
2-4 Ahead
5 Right Turn

It looks to me like physical constraints dictate that lane 5 is rather short
and traffic waiting there would tail back preventing other traffic from
reaching lanes 1-4. Clearing as much right-turning traffic from the junction
*first* in the sequence avoids this, but at the cost of making the junction
more dangerous. The danger is that someone sitting at a red light in lane 4
will see the light for lane 5 change and think it applies to them, taking
off across the junction into the path of right-turning traffic from the
opposite direction. The light(s) for lanes 2-4 are out of the direct line of
vision for someone in lane 5 so the reverse situation doesn't arise when the
phases are in the more usual arrangement.

There is a junction on the A270 in Hove (near where I live) which is even
more constrained in that right turning traffic has to slew across in front
of the waiting 'ahead' traffic before making the right turn.

http://maps.google.co.uk/maps?f=q&hl=en&geocode=&time=&date=&ttype=&q=HOVE+ A270&sll=51.658963,-0.059084&sspn=0.00121,0.002325&ie=UTF8&ll=50.83890 1,-0.178018&spn=0.001231,0.002325&t=k&z=19&iwloc=addr &om=1

The traffic lights all have signs on the poles which read "RIGHT TURNS GO
FIRST", and *still* people try to drive ahead when the right filter changes.

A lot of the above would be avoided if we fell into line with most of the
rest of the world, where the lights for filter lanes have arrows on the red
and amber heads as well as the green (ASCII art diagram below).

D A Stocks


UK:

###
# #
# #
# #
###

###
# #
# #
# #
###

###
# #
#--#
# #
###


Rest Of The World (for example):

###
# #
# -#
# | #
###

###
# #
# -#
# | #
###

###
# #
# -#
# | #
###

On Wed, 31 Oct 2007 03:13:35 -0000, "John Rowland"
wrote:

Conor wrote:
In article , John Rowland
says...
The traffic lights here have three (traffic) phases:
1) turn right from the main road
2) forward or left from the main road
3) forward, left or right from the minor road
...in that order. Every other junction which I know has these three
phases has them in the opposite order.

Does anyone know why this junction is different?

I guess you don't go very far. I know of several sets OTTOMH within 12
miles that work the same.

Thanks. Can you think of anything else those junctions have in common which
might explain it?



You will be waiting a long time for him to name several within 12
miles; he is prone to exaggeration. Also "Can you think" is a bit of
a long shot.


OOMA would have been more accurate than OTTOMH

roadrunner wrote:
On Wed, 31 Oct 2007 03:13:35 -0000, "John Rowland"
wrote:

Conor wrote:
In article , John Rowland
says...
The traffic lights here have three (traffic) phases:
1) turn right from the main road
2) forward or left from the main road
3) forward, left or right from the minor road
...in that order. Every other junction which I know has these three
phases has them in the opposite order.

Does anyone know why this junction is different?

I guess you don't go very far. I know of several sets OTTOMH within
12 miles that work the same.

Thanks. Can you think of anything else those junctions have in
common which might explain it?

You will be waiting a long time for him to name several within 12
miles; he is prone to exaggeration. Also "Can you think" is a bit of
a long shot.

OOMA would have been more accurate than OTTOMH

And yet his answer was more useful than yours.

David A Stocks wrote:
"John Rowland" wrote in
message ...
The traffic lights here have three (traffic) phases:
1) turn right from the main road
2) forward or left from the main road
3) forward, left or right from the minor road
...in that order. Every other junction which I know has these three
phases has them in the opposite order.

Does anyone know why this junction is different?


Looking at the junction on Google Maps the A10 is two lanes per
direction dual carriageway which expands at the junction to five
lanes arranged left to right as follows:

1 Left Turn
2-4 Ahead
5 Right Turn

It looks to me like physical constraints dictate that lane 5 is
rather short and traffic waiting there would tail back preventing
other traffic from reaching lanes 1-4.

Actually, the turning right lanes here are significantly longer than those
at all other Great Cambridge Road traffic lights in London, except Bullsmoor
Lane.

There is a junction on the A270 in Hove (near where I live) which is
even more constrained in that right turning traffic has to slew
across in front of the waiting 'ahead' traffic before making the
right turn.
http://maps.google.co.uk/maps?f=q&hl...oc=addr &om=1

That's horrendous.

In article , roadrunner
says...

You will be waiting a long time for him to name several within 12
miles; he is prone to exaggeration.

Maybe not within 12 but certainly within 20...

Bridlington. A614 junction with Bessingby Road. (technically not a X
roads but a T junction that works in the same order)

Beverley. Norwood Junction with New Walkergate.

Hull. Beverley Road junction with Cottingham Road.

Hull. Beverley Road Junction with Greenwood Avenue.

In fact, many of them in Hull work that way.


--
Conor

I'm not prejudiced. I hate everyone equally.