Region: South West
The Aust (J21) to Wickham (J14) section of M4
Statistics and options.
| Section | Construction started | Opened to traffic |
| Aust to Almondsbury (J21 to J20) | August 1963 | September 1966 |
| Almondsbury Four Level Interchange (J20) | May 1964 | September 1966 |
| Almonsbury to Tormarton (J20 to J18) | April 1964 | January 1966 |
| Tormarton to Wootton Bassett (J18 to J16) | July 1969 | December 1971 |
| Wootton Basset to Liddington (J16 to J15) | July 1969 | December 1971 |
| Liddington To Wickham (J15 to J14) | December 1969 | December 1971 |