| Section | Length (km) | Engineer | Contractor | Tender Price |
| Dartford Tunnel Southern Approach | 2.5 | Kent CC | Laing/Birse | £15.9m |
| Dartford to Swanley (J1 to J3) | 5.3 | SERCU (Kent SU) | Laing | £5.5m |
| Swanley to Sevenoaks (J3 to J5) | 12.9 | Kent CC | Laing | £38.5m |
| Sevenoaks Interchange (J5) | 1.5 | SERCU (Kent SU) | Cementation | £7.2m |
| Sundridge Road to Westerham | 6.3 | SERCU (Kent SU) | Gleeson | £6.3m |
| Westerham to Godstone (J6) | 8.1 | SERCU (Surrey SU) | Bovis | £8.4m |
| Godstone to Reigate (J6 to J8) | 7.2 | SERCU (Surrey SU) | French | £10.4m |
| Reigate to Leatherhead (J8 to J9) | 7.2 | W S Atkins | Farr - Birse | £14.6m |
| Leatherhead interchange (J9) | 4.4 | W S Atkins | Balfour Beatty | £14.3m |
| Leatherhead to Wisley | 6.9 | W S Atkins | Fairclough(AMEC) | £17.2m |
| Wisley to Chertsey (J10 to J11) | 9.4 | W S Atkins | Balfour Beatty | £20.7m |
| Advance bridges | SERCU (Surrey SU) & Gifford | Fairclough(AMEC), Balfour Beatty & Monk | £6.4m | |
| Chertsey to Thorpe (J11 to J12) | 3.8 | SERCU (Surrey SU) | Bovis | £7.6m |
| Thorpe to Egham (J12 to J13) | 4.0 | SERCU (Surrey SU) | Bovis/Fairclough(AMEC) | £9.9m |
| Egham to Yeoveney (J13 to J14) | 1.5 | SERCU (Surrey SU) & Ove Arup | Bovis/Fairclough(AMEC) | £9.9m |
| Yeoveney to Airport spur | 3.2 | SERCU (Surrey SU) | Balfour Beatty | £14.8m |
| Airport spur to M4 (15) | 3.3 | W S Atkins | Cementation | £44.5m |
| M4 to Iver Heath (J15 to J16) | 6.8 | ERCU (Bucks SU) | Wimpey | £25.3m |
| M40 Interchange (J16) | 2.6 | ERCU (Bucks SU) | Tarmac (now Carrilion Construction) | £21.1m |
| M40 to Maple Cross (J16 to J17) | 7.7 | ERCU (Bucks SU) & Halcrow | Laing | £20.0m |
| Maple Cross to Hunton Bridge (J17 to J19) | 9.6 | ERCU | Costain | £5.8m |
| Micklefield to Bedmond Road (J19 to J20) | 5.8 | Colquhoun/ERCU (Herts SU) | Sir A McAlpine/ Fairclough(AMEC) Cons'n | £26.8m |
| Bedmond Road to Bricket Wood (J20 to J21A) | 3.1 | Colquhoun/ERCU (Herts SU) | Balfour Beatty | £17.7m |
| Bricket Wood to London Colney (J21A to J22) | 6.6 | Colquhoun/ERCU (Herts SU) | Edmund Nuttall | £15.2m |
| London Colney to South Mimms (J22 to J23) | 6.0 | Colquhoun/ERCU (Herts SU) | Balfour Beatty | £21.5m |
| South Mimms to Potters Bar (J23 to J24) | 4.3 | ERCU | Balfour Beatty | £4.9m |
| Potters Bar to Waltham Cross (J24 to J25) | 8.5 | GLC | Sir A McAlpine | £15.8m |
| Waltham Cross (J25) to River Lee | 2.9 | ERCU (Herts SU)/ Maunsell | Tarmac (now Carrilion Construction) | £28.6m |
| River Lee to Upshire (J26) | 3.2 | ERCU (Herts SU)/ Maunsell | Tarmac (now Carrilion Construction) | £13.1m |
| Upshire to Theydon Garnon (J26 to J27) | 6.6 | ERCU (Herts SU)/ Maunsell | Laing | £29.1m |
| Theydon Garnon (J27) to Passingford Bridge | 4.6 | ERCU (Essex SU)/ W S Atkins | Costain | £21.2m |
| Passingford Bridge to Brentwood (J28) | 8.3 | ERCU (Essex SU)/ Ove Arup | Laing | £19.9m |
| Brentwood to North Ockendon (J28 to J29) | 8.6 | Mott Hay and Anderson | Costain | £31.1m |
| North Ockendon(J29) to Stifford Road | 4.0 | Mott Hay and Anderson | Laing | £7.2m |
| Stifford Road to Mar Dyke | 2.2 | Mott Hay and Anderson | Laing | £11.0m |
| Dartford Tunnel North Approach | 1.2 | Mott Hay and Anderson | Edmund Nuttall | £11.1m |
| Dartford Tunnel | 2.2 | Mott Hay and Anderson | Balfour Beatty | £33.4m |
