- A666 between A6062 and A6078, Blackburn with Darwen (Grid ref SD679269)
- A666 between M65 and A6062 intersection, Blackburn with Darwen (Grid ref SD680254)
- A666 between A6062 intersection and A6177, Blackburn with Darwen (Grid ref SD680271)
- A666 between St Peter St and Astley Gate, Blackburn with Darwen (Grid ref SD682279)
- A666 between A674 and A674, Blackburn with Darwen (Grid ref SD682280)
- A666 between A6177 and A674, Blackburn with Darwen (Grid ref SD683278)
- A666 between M65 and M65, Blackburn with Darwen (Grid ref SD684244)
- A666 between A674 and A674, Blackburn with Darwen (Grid ref SD684279)
- A666 between A674 and A677, Blackburn with Darwen (Grid ref SD684282)
- A666 between A6119 and Blackburn with Darwen boundary, Blackburn with Darwen (Grid ref SD686313)
- A666 between Lancashire boundary and B6245, Lancashire (Grid ref SD687320)
- A666 between A677 and A6119, Blackburn with Darwen (Grid ref SD688300)
- A666 between Watery Lane and M65 slip, Blackburn with Darwen (Grid ref SD690225)
- A666 between B6245 and Hollies Rd, Lancashire (Grid ref SD690329)
- A666 between Lark St and Watery Lane, Blackburn with Darwen (Grid ref SD698204)
- A666 between Blackburn with Darwen boundary and B6193, Blackburn with Darwen (Grid ref SD700170)
- A666 between B6391 and Lark St, Blackburn with Darwen (Grid ref SD700199)
- A666 between Hollies Rd, Wilpshire and A59, Lancashire (Grid ref SD700336)
- A666 between Longworth Rd and Bolton boundary, Bolton (Grid ref SD706155)
- A666 between B6472 and Longworth rd, Bolton (Grid ref SD710147)
- A666 between A58 and B6472, Bolton (Grid ref SD714130)
- A666 between A6099 and A58, Bolton (Grid ref SD715110)
- A666 between A673 and A6099, Bolton (Grid ref SD717100)
- A666 between A676 and A673, Bolton (Grid ref SD718097)
- A666 between Bradford Street and Folds Road, Bolton (Grid ref SD720095)
- A666 between A575 and A579, Bolton (Grid ref SD727080)
- A666 between A6053 and M61, Bolton (Grid ref SD745054)
- A666 between M61 and A575, Bolton (Grid ref SD745059)
- A666 between A667 and M61, Bolton (Grid ref SD747051)
- A666 between Bolton boundary and A667, Bolton (Grid ref SD754047)
- A666 between M60 and Salford boundary, Salford (Grid ref SD775035)
- A666 between A6044 and M60, Salford (Grid ref SD780025)
- A666 between A6 and A6044, Salford (Grid ref SD795009)