Niklas Karlsson wrote to uk.transport.london on Sun, 9 Jan 2005:

The costs of doing this in the UK today would be prohibitive, both to
highway departments and to private individuals:
[snip]
Oh, I have no doubt. I expect it would be prohibitive in Sweden as well,
had the switchover been postponed until today. I was mostly just
stirring the pot and adding a data point. :-)

I did read somewhere that officials are now regretting not having done
it when Sweden did, as it would have been feasible then, but isn't now.

The land-border matter was fairly crucial as well. Pretty much by
definition, Britain has no land borders (between countries that differ
in something as basic as which side of the road to drive, at least). :-)

There used to be a silly joke going round to the effect that the
Republic of Ireland (with whom we do, of course, have a land border) was
going to change to left-hand drive, but to make it easier, they would do
it in stages: lorries and buses one month, cars and cycles the next.....
Mind you, given that they measure distances in kilometres and speed in
miles per hour (or is it the other way round?), one does wonder....

It is to be hoped that if we ever *do* change to driving on the right, we
don't adopt the Dutch and German rule of traffic joining a roundabout having
priority over traffic already on the roundabout.

Sweden has not; the traffic on the roundabout has priority. (Unless this
has changed very recently.) Anything else seems very silly, really,
IMAO.

In France the traffic on the roundabout has priority, too, and usually
there are large notices telling traffic on the joining road that it
doesn't have priority. A pity the exits aren't (by our standards)
well-signposted - you have to know how the system works!
--
"Mrs Redboots"
http://www.amsmyth.demon.co.uk/
Website updated 2 January 2005