JNugent wrote:
Richard J. wrote:

and downgrade the speed limits,

... in the case of ex-A40(M) to the design speed of the road, and
improving the traffic-flow efficiency at peak times too, so what's
your problem with that?

The A40(M) speed limit used to be 50 on the 2-lane stretch and 60 on
the three-lane stretch. What are they now?

The speed limit reductions I was thinking of were mainluy on the
former A102 at Bow and the A102(M) just north of that (now A12) where
a six-lane highway with hard shoulders is limited to 40mph. Oh, and th
southbound continuation heading for Kent has been reduced from a 60
limit to a 50.

Ex-A40(M) is still 6 lanes; don't know about A102(M);

Speed limit curtailed to an unrealistically low 40 (this on a road
which is a motorway in all but name and part of which used to be a
motorway).
M41 reduced from 6 to
4 in order, I think, to incorporate the junction for the Westfield
Centre (White City), but this hasn't affected traffic-flow
efficiency as the roundabouts at each end are the limiting factor.

And the hard shoulders?

What local junction needs two strips of land 27' wide and a mile long?

The total length of the junction between the starting points of the two exit
slip roads is 0.44 mile (measured on Google Earth) out of a total ex-M41
length of about 0.75 mile. The slip roads are all 2-lane. (Westfield is a
*very* big shopping centre.)


There are now buildings on part of the west side of the former M41,
where the hard shoulder used to be.

The only building is the southbound platform structure of the new Shepherd's
Bush station on the West London Line, right at the southern end of the
ex-M41. Then through the new junction you have 4 lanes of A3220 and 4 lanes
of slip roads, with no hard shoulders. The north-facing slip roads continue
right up to the point where the carriageways separate for the approach to
the Northern Roundabout, and from there it has always been 2-lane. The only
reason for building 3-lane carriageways was as part of the full Motorway
Box.

How else would you have accommodated road traffic for the Westfield Centre
without "wrecking" the road?
--
Richard J.
(to email me, swap 'uk' and 'yon' in address)