|Location Map ( geo)|
|The western end of the interchange|
|M3, M27, A27, A33|
|Junctions related to the A33|
Redbridge Roundabout (Southampton) • Hockley Interchange • Winnall Interchange • Popham Interchange • Bar End Interchange • Three Mile Cross Interchange • Binfields Roundabout • Crockford Roundabout • Memorial Roundabout (Southampton) • Bassett Crossroads • Stag Gates • Charlotte Place • Six Dials • Mayflower Roundabout • Millbrook Roundabout • Kings Worthy Interchange • Bevois Valley Interchange
Chilworth Interchange is junction 4 of the M27. The Chilworth Roundabout (or Clock Roundabout) is just south of the M27, just south of the southern end of the M3, where the A33 meets the A27. Both are numbered junction 14 of the M3.
The junction was originally a crossroads between the A33 and the A27. This was complicated by the arrival of the Chandler's Ford Bypass, which caused the A33 to effectively split into two (the old road and the new road) in the middle of the junction. A flyover was provided in the 1960s, along with a roundabout to the south.
In 1975, the M27 west of the junction opened, ending at a fork on the A33, and a lane drop at the western end. In 1983 the rest of the junction layout opened with the M27 to the east. In 1991 the A33 to the north was upgraded to M3, widening it north of the M27 east merge.
The 1983 extension was controversial and an alternative plan considered terminating the M3 with a modified trumpet in place of the current fork, and widening the recently completed west slips.
In 1998 the eastbound approach to the junction was used to examine a new tiger tail exit. It was estimated that up to 50% of traffic was leaving the road here, and the existing single lane drop was overloaded, leading to poor driver behaviour. The new layout was considered successful in rectifying this. In 2008, the M27 widening resulted in the exit getting the double lane drop it deserved.
The westbound approach was also converted to a tiger tail, and with the completion of the smart motorway project, will also become a double lane drop.
|The MIDLANDS, London, Eastleigh, Winchester|
|The WEST, So'ton Docks & Ferries, Bournemouth||no access from non-motorway routes|
|Portsmouth, Fareham, Eastleigh, Southampton & Airport||no access from non-motorway routes|
|Romsey, Chilworth, N. Baddersley, Southampton Science Park|
|Swaythling, Airport (A335), Crematorium|
|City centre, Docks|
|Chandlers Ford, Hypermarket||Winchester Road|
|Hotel and Conference Centre||Bracken Place. Traffic heading from Southampton sent up A27, over M3 and back down again|