John Rowland wrote to uk.transport.london on Tue, 7 Sep 2004:

Except I don't think that would apply to a full-blown road.
You need a "no entry" to stop the motorised traffic.

The safest way to achieve this would be to put in a traffic island 1 metre
from the kerb, and have No Entry signs on the large entrance, and Cycle Only
signs on the small entrance.

This is what they do outside my block of flats - the cyclists have their
own lane, blocked off by a narrow kerb. As I said earlier in the
thread, though, the "No Entry" sign is more honoured in the breach than
in the observance.
--
"Mrs Redboots"
http://www.amsmyth.demon.co.uk/