On Wed, 23 Sep 2009 14:15:44 +0100, Adam wrote:

Can these vehicles (looks like some kind of cherry picker) be legally
driven on the public highway?

http://maps.google.co.uk/maps?f=q&so.... 05,,0,20.78

yes but they are limited in the distance they are permitted to travel.
You will often see farm vehicles and factory forklifts/cranes etc. on
the public highway. They are permitted subject to certain conditions.