(Does anyone want to add a review of the M27?) There is only one service station: Rownhams. Curiously, there is no Junction 6.
M27 J6. In the late 60s - early 70s, a motorway was planned from where M27 J6 would have been, S then W through the heart of Southampton to an interchange with buses, ferries & trains somewhere a bit West of the Central Station. Local protest groups got together, and managed to prevent the council inflicting on Southampton (or Basingstoke by Sea, as I'm sure it would prefer to be known) the kind of damage caused by inner motorways to Leeds & Glasgow, for example. I have a friend who's got a copy of the ``protest booklet'', showing the planned route and land take - Sotonians had a very lucky escape, but by the time they did, the numbering scheme was planned.
A service area was also planned for the Eastern part of M27 - alongside the East slip roads for J9. Like the service area planned etween J6 and J7 of the M3, it It was never built, but the Westbound exit slip still reatins its full length of 1 mile from diverge nose to roundabout - the longest sliproad to a roundabout? This is very useful now, owing to the queue lengths that build up on that diverge. The Eastbound merge was shortened many years ago to a more conventional length, the spare bit being used as a hardstanding for ballast storage. Until recently, a second tapering merge was apparent on the hard shoulder at the end of this, but the whole section's being resurfaced at the moment (no more concrete!), so I'm not sure if the ``blind merge'' will survive.