Rupert Candy wrote:
Earl Purple wrote:

It is a primary route. I don't know if it always has been though,
before they declassified the part of the West Cross Route that
used to be the M41.

Indeed (though the A-Z doesn't distinguish primary routes from
ordinary A-roads). I wonder if any other primary routes (other than
tunnels or bridges) are closed at night?

Now if only they'd build a "proper" West Cross Route (as I have
proposed and similar to what was originally planned) they would
divert major traffic away from Kensington and Chelsea and onto a
grade-separated non-residential route towards Hammersmith instead
(bypassing Fulham and Putney to meet the A3 near Tibbetts).

That would be very useful, particularly if combined with a
grade-separated Victoria Embankment/Cheyne Walk (!)

Grade-separated = destroying the London street scene / river frontage,
and probably destroying many homes and workplaces too.
--
Richard J.
(to e-mail me, swap uk and yon in address)

Richard J. wrote:

Grade-separated = destroying the London street scene / river frontage,
and probably destroying many homes and workplaces too.

It was meant to be tongue-in-cheek, but every other European city seems
to manage to build tunnels for this sort of thing without disrupting
the streetscape (at least, once they have been constructed!) Brussels
is the best example, but there are many others.

Richard J. wrote:

Grade-separated = destroying the London street scene / river frontage,
and probably destroying many homes and workplaces too.
--
Richard J.

Grade-separating is a clever way to separate through traffic from local
traffic wishing to access the area, improving conditions for both.

Warwick Gardens and some of the other roads in the West Cross Route
like Edith Grove / Gunter Grove are residential roads.

It can't be bad for the environment, at least for residents of those
areas, to push traffic away onto their own newly-built road which, if
built in reality, would probably run close to the railway. Tunnelling
can be preferable to raised roads if the tunnels are reasonably short,
though I'd propose that a new bridge be built over the Thames. Bridges
and high-up roads don't need to be ugly structures - some of them can
be built with very nice architecture. And they are not as noisy as you
think. The areas under these raised roads can also be used conveniently
for open markets as they provide some shelter from the rain.

(Note, I would also connect the top of the WCR with the M1 at Staples
Corner).

http://img.photobucket.com/albums/v2...ossBypass1.jpg

"Earl Purple" wrote in message
ps.com...

http://img.photobucket.com/albums/v2...ossBypass1.jpg

LOL.

--
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

Earl Purple wrote:
Richard J. wrote:

Grade-separated = destroying the London street scene / river frontage,
and probably destroying many homes and workplaces too.
--
Richard J.


Grade-separating is a clever way to separate through traffic from local
traffic wishing to access the area, improving conditions for both.

Warwick Gardens and some of the other roads in the West Cross Route
like Edith Grove / Gunter Grove are residential roads.

It can't be bad for the environment, at least for residents of those
areas, to push traffic away onto their own newly-built road which, if
built in reality, would probably run close to the railway. Tunnelling
can be preferable to raised roads if the tunnels are reasonably short,
though I'd propose that a new bridge be built over the Thames. Bridges
and high-up roads don't need to be ugly structures - some of them can
be built with very nice architecture. And they are not as noisy as you
think. The areas under these raised roads can also be used conveniently
for open markets as they provide some shelter from the rain.

(Note, I would also connect the top of the WCR with the M1 at Staples
Corner).

No, no, no, please, no, to all of that. They planned to do it some time
ago (http://www.btinternet.com/~roads/lon...ringway1.html).

Of course, the Westway was a roaring success for the residents of the
area it cut through. These urban motorways only serve to generate new
car traffic (whether tunnelled or not), and are also incredibly
expensive (particularly if tunnelled). Which is thankfully why you'll
never see a grade-separated South Circular any time soon.

--
Dave Arquati
Imperial College, SW7
www.alwaystouchout.com - Transport projects in London

Dave Arquati wrote:

No, no, no, please, no, to all of that. They planned to do it some time
ago (http://www.btinternet.com/~roads/lon...ringway1.html).

I know about the planned ringway. I don't think they should go ahead
with the whole of that though.

Of course, the Westway was a roaring success for the residents of the
area it cut through.

Are you sure? Traffic has always headed into London from the West and
it would do so without the A40 and the elevated M4, probably on the A4
instead, so the Cromwell Road, with its museums and hotels would simply
be totally choked. And those who don't use the A4 would use the A4020
(much of which used to be the A40) passing through Ealing etc. even
though they have intention to go to Ealing, whilst conflicting with
local traffic.

The little bit of the West Cross Route that comes South off the A40 is
a fairly useless road - it's good down to Shepherds Bush then takes you
through residential roads that were never meant to be a highway. Going
Northbound, if you want to continue North you have to take A40 and A406
or work your way through the local areas of Harlesden and Neasden. Its
only real purpose is as a relief road for Wood Lane.

These urban motorways only serve to generate new car traffic

Maybe a little but most of it will just be diverted off other roads.
For example someone coming from Portsmouth heading North may well go up
the A3, onto this road and subsequently the M1 rather than using the
Western stretch of the M25. Certainly those who live in Kingston going
North are more likely to use it. But are these people going to
specifically make more journeys by car just because the road is there?

If they want to encourage more people to use trains then improve the
railways too.

(whether tunnelled or not), and are also incredibly expensive
particularly if tunnelled).

It's more expensive to build a tunnel than a bridge but it does mean
they don't have to buy up land and compulsory purchase orders may
obviously cost more.

Talking of cost though, do you know how much revenue is lost everyday
through traffic queues?

And actually, a road, if used properly, will usually take a greater
volume than a railway. On a D2 dual carriageway, for example, if cars
are travelling at a 2-second gap, you get 30 cars in each lane passing
per minute. If each car has 2 occupants, that's 120 passengers a minute
in each direction. You'd need to run a very frequent train service to
carry that many.

Anyway, they were supposed to be raising all this money to improve
roads through the congestion charge but all I've seen is totally
unnecessary roadworks on roads that aren't broken. But then we know Ken
is anti-car.

Which is thankfully why you'll
never see a grade-separated South Circular any time soon.

Do you live and drive in the South of London?

Dave Arquati
Imperial College, SW7
www.alwaystouchout.com - Transport projects in London

On Tue, 2 Aug 2005, Earl Purple wrote:

And actually, a road, if used properly, will usually take a greater
volume than a railway. On a D2 dual carriageway, for example, if cars
are travelling at a 2-second gap,

Then they're travelling too close together. Unless the traffic's flowing
at 40 mph, at which speed 2 seconds is almost enough.

I'm basing this on highway code rule 105, which says:



105: Drive at a speed that will allow you to stop well within the distance
you can see to be clear. You should

* leave enough space between you and the vehicle in front so that you
can pull up safely if it suddenly slows down or stops. The safe rule is
never to get closer than the overall stopping distance (see Typical
Stopping Distances diagram below)



The diagram it references gives the following stopping distances for
various speeds:

Speed (mph) Distance (m)

20 12
30 23
40 36
50 53
60 73
70 96

If you divide the distances by the speeds, you get the following times:

Speed (mph) Time (s)

20 1.35
30 1.73
40 2.03
50 2.39
60 2.74
70 3.09

If you're talking about a dual carriageway, then presumably you're hoping
for a speed of 70 mph, which would require a gap slightly longer than 3
seconds. Of course, if you're talking about a road in London, then 40 mph
is probably quite realistic!

you get 30 cars in each lane passing per minute. If each car has 2
occupants,

Then that's very good going. The average occupancy is about 1.5.

that's 120 passengers a minute in each direction.

Or, if you use realistic numbers, 60.

You'd need to run a very frequent train service to carry that many.

Let's go with your number of 120 pax/min, which is 7200 pax/hour.

Let's compare that to a reasonably modern and efficient tube line, the
Central - the nominal capacity of one of its trains is 620 passengers, and
it runs 30 trains per hour, for a capacity of 18600 pax/hour, over two and
a half times that of your motorway, for a fraction of the land take. And
if you have the ability to use 12-car mainline-gauge trains, like
Crossrail, then it's even higher.

tom

--
We must perform a quirkafleeg

In article , Tom
Anderson wrote:
Then they're travelling too close together. Unless the traffic's
flowing at 40 mph, at which speed 2 seconds is almost enough.

Your arithmetic is wrong in that during the period you are stopping
your average speed is only going to be about half the initial speed,
so you would need to double your calculated times. What you ignore,
and what lies behind the 2 second rule on faster roads with good
visibility is that the car in front is not going to stop dead -
unless something really catastrophic happens.

Being a old guy who passed his test in imperial days the formula for
stopping distance was m(1+m/20) feet: the first term is basically the
distance travelled whilst your brain is getting your foot to press
the brake, the second the actual time needed to stop.

So if the car in front is doing 60 (88ft/sec) the total stopping
distance is 240ft - 60ft thinking, 180ft to actually stop. You're 2
seconds (176ft) behind the car in front when you see his brake
lights. He comes to a halt 180ft further down the road - 356ft from
where you are at the point when you see his brake lights. Assuming
your reactions and brakes are equal to the Highway Code you stop in
240ft from this point, 100 ft or so to spare.

--
Tony Bryer

Tony Bryer writes:
Being a old guy who passed his test in imperial days the formula for
stopping distance was m(1+m/20) feet: the first term is basically the
distance travelled whilst your brain is getting your foot to press
the brake, the second [that travelled in] the actual time needed to stop.

However, that is an oversimplification. The distance needed to stop
under maximum braking force (or any particular force) varies as the
*square* of the speed.
--
Mark Brader | "Forgive me if I misunderstood myself, but
Toronto | I don't think I was arguing in favour of that..."
| -- Geoff Butler