In message , Bob Martin
writes

IIRC, the plan for the M25 was that it should have 4 service areas, of which
we now have 3 (South Mimms, Thurrock, Clackett Lane).

Logically, the 4th would sit somewhere around junction 10 (A3) or junction
11 (M3).

No. 4 was originally intended to be at Iver, a little north of junction
15 - the plan was abandoned around 1990 due to M25 widening.

As there is another bout of works around J11 at the moment, has
anyone heard if they plan to recitify the deficiency at the same time ? Or,
for that matter, ever?

Cobham (between jcts 9 and 10) was the subject of a recent public
enquiry looking into a number of new motorway service areas west of
London. However, although the enquiry has finished, I last heard that it
was not due to report until 2005 and was waiting, amongst other things,
for traffic projections post Heathrow T5.

--
Paul Terry