Lights blue touchpaper...

TinyURL:

http://tinyurl.com/2uq5mr

John Hearns said:

http://www.telegraph.co.uk/motoring/main.jhtml;jsessionid=JVAR2VXUL3N33QFIQMFSFGGAVCBQ0IV0?xml=/motoring/2007/01/27/mrjon27.xml
# Yesterday I had to take a half-mile walk in the early evening. The air
was damp and so was the ground. When I got to the traffic-choked main
road, however, I noticed that it and the pavement were dry, presumably
warmed by the heat of engines and exhaust systems. I can only surmise
from this (very unscientifically, I admit) that the vehicular
contribution to global warming (actually only 0.03 per cent) is caused
by traffic jams created by the likes of Ken Livingstone, not by drivers
going as quickly as they can. The purpose of most of the dodgy
statistics we are fed is to clobber us in a manner most voters will find
more acceptable than VAT or income tax rises.

Yup, that's Honest John trying to claim that the contribution to global
warming by cars is the heat given out by their engines.

You misread, or are misrepresenting what he is saying.

Quoted message said:

Nothing to do with greenhouse gases.

Where does he say that?

He is suggesting that sitting in jams /is/ causing more greenhouse gases
to be emitted than using the engine efficiently for propulsion. Do you
disagree?

Quoted message said:

I'm sure he knows better - just seems to be a bizarre way of having a
dig at Ken Livingstone.

Jams, caused by poor road provision, and poor traffic management, create
unnecessary emissions. Do you disagree with that?

Perhaps you believe that the London road system, and its traffic
management, is optimised to cause the least amount of queuing traffic?

--
Matt B

Matt B said:

John Hearns said:

http://www.telegraph.co.uk/motoring/main.jhtml;jsessionid=JVAR2VXUL3N33QFIQMFSFGGAVCBQ0IV0?xml=/motoring/2007/01/27/mrjon27.xml
# Yesterday I had to take a half-mile walk in the early evening. The
air was damp and so was the ground. When I got to the traffic-choked
main road, however, I noticed that it and the pavement were dry,
presumably warmed by the heat of engines and exhaust systems. I can
only surmise from this (very unscientifically, I admit) that the
vehicular contribution to global warming (actually only 0.03 per cent)
is caused by traffic jams created by the likes of Ken Livingstone, not
by drivers going as quickly as they can. The purpose of most of the
dodgy statistics we are fed is to clobber us in a manner most voters
will find more acceptable than VAT or income tax rises.

Yup, that's Honest John trying to claim that the contribution to
global warming by cars is the heat given out by their engines.

You misread, or are misrepresenting what he is saying.

Quoted message said:

Nothing to do with greenhouse gases.

Where does he say that?

He is suggesting that sitting in jams /is/ causing more greenhouse gases
to be emitted than using the engine efficiently for propulsion. Do you
disagree?

Quoted message said:

I'm sure he knows better - just seems to be a bizarre way of having a
dig at Ken Livingstone.

Jams, caused by poor road provision, and poor traffic management, create
unnecessary emissions. Do you disagree with that?

Perhaps you believe that the London road system, and its traffic
management, is optimised to cause the least amount of queuing traffic?

Well, It can't be denied that the fuel used while the vehicle is
stationary is wasted, but things aren't quite as simple as that.
If charging motorists more to dissuade them seems ineffective it may
well be that reducing the utility of them might provide the motivation
needed to get them to use the alternatives. It's the flip side to the
build bigger roads and the traffic will increase phenomenon.
I would also argue that if cars do use a significant amount of fuel
while in heavy, slow moving traffic then they have not been properly
designed for the real world.

Oh, and by the way, to observe that;
quote
I noticed that it and the pavement were dry, presumably warmed by the
heat of engines and exhaust systems.
unquote
and connect this DIRECTLY with global warming does suggest a
misunderstanding.

--
Roger Thorpe

My email address is spamtrapped. You can work it out!

Roger Thorpe said:

Oh, and by the way, to observe that;
quote
I noticed that it and the pavement were dry, presumably warmed by the
heat of engines and exhaust systems.
unquote
and connect this DIRECTLY with global warming does suggest a
misunderstanding.

Given that the poor man had just "had" to take a half mile walk I can
quite understand that he was under emotional strain and not thinking
clearly, but he's not comparing like with like anyway. The ground was
damp, the congested busy road was not, but he hasn't compared with an
uncongested busy road. If he were to do so, he would most probably find
that that is also dry. This can be observed on many roads in central
London at times of day when the traffic levels are low enough to allow
free flow between one set of lights and the next.

-dan

--
http://www.coruskate.net/

In article <[email hidden]>, Daniel Barlow says...

Quoted message said:

Given that the poor man had just "had" to take a half mile walk I can
quite understand that he was under emotional strain and not thinking
clearly, but he's not comparing like with like anyway. The ground was
damp, the congested busy road was not, but he hasn't compared with an
uncongested busy road. If he were to do so, he would most probably find
that that is also dry. This can be observed on many roads in central
London at times of day when the traffic levels are low enough to allow
free flow between one set of lights and the next.

-dan

Nah. I'm sure there are people around here that would argue a true like
for like comparison would be with a disused railway line in Benidorm in
the summer - after all the OP was thinking about his forthcoming holiday
in Spain when he wrote what he did!

Roger Thorpe said:

Matt B said:

Jams, caused by poor road provision, and poor traffic management,
create unnecessary emissions. Do you disagree with that?

Perhaps you believe that the London road system, and its traffic
management, is optimised to cause the least amount of queuing traffic?

Well, It can't be denied that the fuel used while the vehicle is
stationary is wasted, but things aren't quite as simple as that.
If charging motorists more to dissuade them seems ineffective

You assume that suppressing traffic is the only way to alleviate the
problem. Another solution is to make/allow traffic to flow more freely.
We had a notorious traffic problem on a t-junction junction near us.
The morning and evening rush resulted in long queues. The problem was
solved by dividing the existing road space on the 'stem' into two lanes
out and one lane in (it was one out, one in before), so that traffic
waiting to turn right didn't hold-up traffic waiting to turn left.
Simple, but effective.

The problem in London though is the conflict of interest between
allowing traffic to flow freely and justifying the revenue-raising
congestion charge.

Quoted message said:

it may
well be that reducing the utility of them might provide the motivation
needed to get them to use the alternatives.

Or /increasing/ the 'utility' of the alternatives. A free door-to-door
bus service for schools, offices, and shops might tempt some to leave
their cars at home.

Quoted message said:

It's the flip side to the
build bigger roads and the traffic will increase phenomenon.

That is a fallacy though. The only increase is where there is already
latent demand, or where the resulting road network is poorly balanced
(like the M25). I'm sure you can think of many roads which have been
built in the last 50 years which are not constantly congested.

Quoted message said:

I would also argue that if cars do use a significant amount of fuel
while in heavy, slow moving traffic then they have not been properly
designed for the real world.

Or the road and traffic planners haven't actually kept pace with real
world demands of their paymasters and customers.

--
Matt B

Matt B 'matt.bourke'@nospam.london.com said:

He is suggesting that sitting in jams /is/ causing more greenhouse gases
to be emitted than using the engine efficiently for propulsion. Do you
disagree?

It does indeed (although this can be reduced by drivers switching off
warm engines in longer delays). This is why the car is not a sensible
mode of transport in a setting where mass car use will necessarily
cause jams.

Quoted message said:

Jams, caused by poor road provision, and poor traffic management, create
unnecessary emissions. Do you disagree with that?

Jams, whatever the cause, create emissions. Excessive use of space-
wasting types of vehicle is a common cause.

Quoted message said:

Perhaps you believe that the London road system, and its traffic
management, is optimised to cause the least amount of queuing traffic?

No - it is clearly not yet effective at discouraging the inefficient
use of road space.

Jon

Jon said:

Matt B 'matt.bourke'@nospam.london.com said:

He is suggesting that sitting in jams /is/ causing more greenhouse gases
to be emitted than using the engine efficiently for propulsion. Do you
disagree?

It does indeed (although this can be reduced by drivers switching off
warm engines in longer delays). This is why the car is not a sensible
mode of transport in a setting where mass car use will necessarily
cause jams.

It is also a reason why we should not accept that there is nothing more
that can be done to improve traffic flow - other than reducing traffic.

Quoted message said:

Quoted message said:

Jams, caused by poor road provision, and poor traffic management, create
unnecessary emissions. Do you disagree with that?

Jams, whatever the cause, create emissions. Excessive use of space-
wasting types of vehicle is a common cause.

I would suggest that a more common cause is poor traffic management.

How often are cars stationary at traffic lights when the junction is
completely clear of any reason why they shouldn't proceed?

How often does an unnecessary/deliberate bottleneck cause a tailback
upstream where there is no congestion downstream?

Quoted message said:

Quoted message said:

Perhaps you believe that the London road system, and its traffic
management, is optimised to cause the least amount of queuing traffic?

No - it is clearly not yet effective at discouraging the inefficient
use of road space.

Do you think that London roads and their traffic management systems,
such as junction design etc. are optimised to minimise queuing?

--
Matt B

Matt B said:

I would suggest that a more common cause is poor traffic management.

How often are cars stationary at traffic lights when the junction is
completely clear of any reason why they shouldn't proceed?

How often does an unnecessary/deliberate bottleneck cause a tailback
upstream where there is no congestion downstream?

In london 20 years ago the sequencing of lights certainly used to be
arranged to encourage a smooth flow. The only way that I ever actually
noticed its operation was when travelling AWAY from the centre during
the INWARD rush hour or vice versa. that's when you really did catch
every red light.
Are things different now?

--
Roger Thorpe

My email address is spamtrapped. You can work it out!

Roger Thorpe said:

Matt B said:

I would suggest that a more common cause is poor traffic management.

How often are cars stationary at traffic lights when the junction is
completely clear of any reason why they shouldn't proceed?

How often does an unnecessary/deliberate bottleneck cause a tailback
upstream where there is no congestion downstream?

In london 20 years ago the sequencing of lights certainly used to be
arranged to encourage a smooth flow. The only way that I ever actually
noticed its operation was when travelling AWAY from the centre during
the INWARD rush hour or vice versa. that's when you really did catch
every red light.
Are things different now?

Light sequencing is organised to optimise overall traffic flow within the
abilities of the designers to manage this.

I know that in London the timings are dynamically altered with traffic
conditions. I imagine it's the case in much of the rest of the country.

If Matt B has any ideas of where this dynamic timing is inadequate, I'm sure
TfL would love to hear from him.

A

Roger Thorpe said:

Matt B said:

I would suggest that a more common cause is poor traffic management.

How often are cars stationary at traffic lights when the junction is
completely clear of any reason why they shouldn't proceed?

How often does an unnecessary/deliberate bottleneck cause a tailback
upstream where there is no congestion downstream?

In london 20 years ago the sequencing of lights certainly used to be
arranged to encourage a smooth flow. The only way that I ever actually
noticed its operation was when travelling AWAY from the centre during
the INWARD rush hour or vice versa. that's when you really did catch
every red light.
Are things different now?

Didn't they tamper with the phasing before congestion charging was
introduced to "bolster their case" that congestion was getting worse?

Additionally, we now have many more sets of traffic lights, and each set
now has longer "dead" periods when nothing is allowed to enter the junction.

I've often witnessed, and often heard others mention, that traffic light
junctions flow more freely when the lights are out-of-order.

Haven't you ever been at the head of a queue at a junction waiting for a
light to turn green when the junction is already perfectly clear, and
nothing has crossed it for 30 seconds or more? That is a wanton waste
of road capacity which should be eliminated before they have the cheek
to charge for road use.

--
Matt B

Ambrose Nankivell said:

Light sequencing is organised to optimise overall traffic flow within the
abilities of the designers to manage this.

I know that in London the timings are dynamically altered with traffic
conditions. I imagine it's the case in much of the rest of the country.

If Matt B has any ideas of where this dynamic timing is inadequate, I'm sure
TfL would love to hear from him.

Do you know of a /single/ light controlled junction left in the whole
country that doesn't have a dead period between each change when /all/
the lights are on red?

That is an unnecessary waste of road lane capacity for umpteen seconds
during each light change. Then multiply it by the number of changes per
cycle at a given junction - and then by the number of light cycles per
day - and then by the number of road lanes entering the junction - and
then by the number of light-controlled junctions in the city. An awful
lot of waste.

--
Matt B

In article said:

Matt B 'matt.bourke'@nospam.london.com said:

He is suggesting that sitting in jams /is/ causing more greenhouse gases
to be emitted than using the engine efficiently for propulsion. Do you
disagree?

It does indeed

But that's completely irrelevent to "Honest John"'s observation that
the busy road was drier, which didn't mention greenhouse gases at all.

Alan Braggins said:

In article <[email hidden]>,

Jon said:

Matt B 'matt.bourke'@nospam.london.com said:

He is suggesting that sitting in jams /is/ causing more greenhouse
gases to be emitted than using the engine efficiently for
propulsion. Do you disagree?

It does indeed

But that's completely irrelevent to "Honest John"'s observation that
the busy road was drier, which didn't mention greenhouse gases at all.

Especially not the greenhouse gas and car exhaust constituent known as water
vapour.

A

"Matt B" <"matt.bourke"@nospam.london.com> wrote in message
news:[email hidden]...

Quoted message said:

Ambrose Nankivell said:

Light sequencing is organised to optimise overall traffic flow within the
abilities of the designers to manage this.

I know that in London the timings are dynamically altered with traffic
conditions. I imagine it's the case in much of the rest of the country.

If Matt B has any ideas of where this dynamic timing is inadequate, I'm
sure TfL would love to hear from him.

Do you know of a /single/ light controlled junction left in the whole
country that doesn't have a dead period between each change when /all/ the
lights are on red?

Pentagon Island in Derby for one. Admittedly it's not a junction as such
but the principle is the same. As soon as the light in one direction is red
you get the red/amber signal on the other direction. Now I know that
pedantically speaking for the couple of seconds of the red/amber phase all
directions are on red, but given the tendancy of some road users to either
set off a second or two before green or conversly to go through on the
first couple of seconds of red you really don't want to see less separation
between the "go" phases.

Quoted message said:

That is an unnecessary waste of road lane capacity for umpteen seconds
during each light change. Then multiply it by the number of changes per
cycle at a given junction - and then by the number of light cycles per
day - and then by the number of road lanes entering the junction - and
then by the number of light-controlled junctions in the city. An awful
lot of waste.

What is your value for "umpteen"? - Your actual measured value for this
period of time? If the separation between the phases is too small then any
time saved will be offset by the amount of time it takes to clear the
wreckage from the junction.

--

Nigel

Nigel Randell said:

"Matt B" <"matt.bourke"@nospam.london.com> wrote:

Quoted message said:

Quoted message said:

Do you know of a /single/ light controlled junction left in the whole
country that doesn't have a dead period between each change when /all/ the
lights are on red?

...

Quoted message said:

That is an unnecessary waste of road lane capacity for umpteen seconds
during each light change. Then multiply it by the number of changes per
cycle at a given junction - and then by the number of light cycles per
day - and then by the number of road lanes entering the junction - and
then by the number of light-controlled junctions in the city. An awful
lot of waste.

...
If the separation between the phases is too small then any
time saved will be offset by the amount of time it takes to clear the
wreckage from the junction.

How do we manage at junctions /without/ lights? How do we manage when
the lights are out? Why are many European towns removing traffic lights
to improve safety and reduce congestion? Have traffic light collisions
been eliminated by this tactic?

--
Matt B

Matt B said:

Ambrose Nankivell said:

Light sequencing is organised to optimise overall traffic flow within
the abilities of the designers to manage this.

I know that in London the timings are dynamically altered with traffic
conditions. I imagine it's the case in much of the rest of the country.

If Matt B has any ideas of where this dynamic timing is inadequate,
I'm sure TfL would love to hear from him.

Do you know of a /single/ light controlled junction left in the whole
country that doesn't have a dead period between each change when /all/
the lights are on red?

On the way to where I work, there's frequently a light controlled
junction that goes out of action. A main crossroads, drivers have to use
their wits. But in all that, unlike when it's controlled by traffic
lights, I've never seen a queue. Drivers take it slower, are more
cautious, but are off.

I've heard other suggestions, like, permitting left turns on a red light
(where road is clear), kind of like the right turns in America....

Just some thoughts....

Cya
Simon

Matt B said:

Roger Thorpe wrote:

Quoted message said:

Quoted message said:

it may well be that reducing the utility of them might provide the
motivation needed to get them to use the alternatives.

Or /increasing/ the 'utility' of the alternatives. A free door-to-door
bus service for schools, offices, and shops might tempt some to leave
their cars at home.

I would happily take the bus to work, if it didn't take an hour and a
half to get there compared to 30 minutes by car, not to mention the
frequent smells of "blow" that drifs from the top deck whenever I've
been on a bus.

Then of course there's the undeniable fact, that, well, I do actually
need a car for work... it's in the nature of my job.

Perhaps we should just get back to telling people "YOU HAVE NO CHOICE,
YOU WILL SEND YOUR KIDS TO THE LOCAL SCHOOL, YOU WILL GO TO THE LOCAL
HOSPITAL". Eh, but that'll only be achieved by decent investment to
bring school and health standards up. How shall we do that? oh I know,
lets tax the motorist.

"Matt B" <"matt.bourke"@nospam.london.com> wrote in message
news:[email hidden]...

Quoted message said:

Nigel Randell said:

"Matt B" <"matt.bourke"@nospam.london.com> wrote:

Quoted message said:

Quoted message said:

Do you know of a /single/ light controlled junction left in the whole
country that doesn't have a dead period between each change when /all/
the lights are on red?

...

Quoted message said:

That is an unnecessary waste of road lane capacity for umpteen seconds
during each light change. Then multiply it by the number of changes per
cycle at a given junction - and then by the number of light cycles per
day - and then by the number of road lanes entering the junction - and
then by the number of light-controlled junctions in the city. An awful
lot of waste.

...
If the separation between the phases is too small then any time saved
will be offset by the amount of time it takes to clear the wreckage from
the junction.

How do we manage at junctions /without/ lights?

Sounds like you need to talk with your driving instructor ;-)

Quoted message said:

How do we manage when the lights are out?

Usually with difficulty, in fact faulty traffic lights are often warned
about on radio traffic bulletins so that they can be avoided.

Why are many European towns removing traffic lights

Quoted message said:

to improve safety and reduce congestion?

Which ones? Do you have a reference?

In the US many crossroads are uncontrolled and operate on the "4 way stop"
principle where you stop at the junction and remain there until every
vehicle which was already there has gone. No one has priority based on
which road they are on. Often these junctions have traffic lights (can be
used at peak periods) but are denoted as 4 ways by a red flashing light. It
does work for relatively light traffic, but for busy grid roads you need the
alternating priority at intersections that traffic lights give.

Quoted message said:

Have traffic light collisions been eliminated by this tactic?

Obviously. No traffic lights = no traffic light collisions. Other
collisions are available.

--

Nigel