wrote:

This is lots of peoples experience with Sustrans though. That the people
there don't ride bikes. 12mph is slow.

I think the problem is possibly that someone took a figure for an
average speed and assumed that's what everyone always goes at. ICBW but
I've heard 11 or 12 as a CTC (or similar) measure of average speed, but
of course that is something that includes stops for all sorts of faffing
and is meant as something to plan how long 50 miles will take you taking
everything into account, not something to say you'll be typically doing
11 or 12 mph at any point you're moving on the bike.

on a sustrans path would obviously be wrong, but a design speeed of 18-20mph
would make them a lot safer.

Agreed. With a tailwind and a helpful slope it's very easy to get to
that without trying to race at all, and having spurious chicanes etc.
thrown in just really doesn't endear me to the designers at those speeds
with 4 panniers of camping gear and someone coming the other way.

Another factor in the design, as with the extensive Tour de Scheme you
get in the torturous attempts to avoid anything resembling a major road
in towns, is it's often lowest common denominator stuff for the
Cannonical Sustrans User, which judging by the pictures you see of Nice
People Having A Nice Time are occasional cyclists doing leisure rides on
a bonny day with a young family. I'm all for them getting out there,
but I don't see why their presence has to make life a PITA for the likes
of me. I can negotiate other users safely and politely, I don't need
traffic engineering to force my hand.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/