In the case of Clacket Lane clockwise services, anyone is allowed to
access
via the local road (which not surprisigly is called Clacket Lane) so long
as
they are booked into the hotel in the service station. I don't know if
similar rules apply for the hotel at Scratchwood or any other services.

It's a similar situation at Heston services on the M4. If you're coming
from the West you have to exit onto a series of local roads (including some
******* speed humps) and then enter the services the other side, where
there's an intercom to let you in. Don't know what's stopping people from
saying they're going to book in when they arrive, but if you regularly do it
then you'd probably get done (signs mention the word 'prosecution') so not
really worth it, as J3 is only a few minutes away, and if you're heading
into town from there you're much better off on the A4 anyway at any time of
day or night.

It's a handy exit point if the queues are particularly bad heading into
London though - a while back I was heading into London late in the
afternoon, and thought I'd turn off for the services and re-join, to avoid
the bunching around the services, and just as I got to the top of the
slip-road the traffic news came on and anonunced that the A4 into town is
closed at the Sutton Court Road traffic lights (at the end of the M4). So I
cut through Heston onto the A4, and I could see it all grinding to a halt
after Gilette Corner, so I turned right there and went in on the A315, where
the main flow there is out of town (just for local traffic,
Isleworth/Brentford, some bits of Hounslow), got to Kew Bridge no probs, and
then cut through the South Circular (against the main flow that time of
day), through Mortlake, Barnes and over Putney Bridge (all against the main
flow) - did Slough to Chelsea in about 40 minutes, not bad considering the
main arterial route into town was closed!! That's why they don't want
everyone doing it - all the other routes would clog up to buggery.

Peter