In article ,
Roland Perry wrote:
But we are speaking *average* speeds, not the fastest possible.

Yes; but you said that trunk roads in London were so congested that
the average speed couldn't be more than 8mph. But a journey I made,
during the friday evening rush hour, had an average speed well in
excess of 8mph - and the fastest section - by far - was a trunk
road!

And that is a direct counter to your argument.


--
Mike Bristow