|M27 Junction 12|
|Location Map ( geo)|
|M27, M275, A3, A27, A397|
|Junctions related to the A397|
Junction 12 of the M27 is made up of three separate interchanges, each originally planned as three roundabout interchanges: one with the 'M274' spur to the A27 and A3, another with the M275 and a third with the A3. The creation of a free-flow M275 junction meant that the junction layout needed to be changed into one big junction.
This junction is home to two motorway multiplexes (which in and of themselves are rare) - the bits of motorway between the M275 and the A27 to Brighton, and the M275 and the A3/A27 crossroads, are both M27 and M275.
The signalised crossroads at the end of the spur was a large roundabout until 2005. Before the motorway opened, it was a much smaller roundabout.
Today the junction is known as Port Solent Interchange, after the marina which opened in the 1990s in one of the corners of the junction. During planning, it was treated as three separate junctions: the west trumpet being Paulsgrove Interchange, the core central section being Portsmouth Interchange and the eastern section being Portsbridge Roundabout. As a complex, it was referred to as (Portsmouth) Harbour Interchange.
Some maps show the junction being further south down the M275.
|The WEST, Southampton, Fareham, Gosport|
|Portsmouth, Ferries, Southsea & North End|
|London (A3(M)), Portsmouth (E), Havant, Brighton|
|Waterlooville, Cosham, Hospital, Paulsgrove|
|Hillsea, North End, Fratton, Copner, Portsmouth (W), Ferries|
|Fareham, Portchester, Superstore & Business Parks|
|Waterlooville, Cosham, Highbury college, Southwick, London, Petersfield||A397 number appears on one roundabout sign only|
|Western Road Industrial Estate||Northarbour Road|