Forms parts of the historical route of Watling Street. The section from M1 J4 north of Edgware to N. of Dunstable is now numbered A5183. The A5 now starts at M1 J11A and runs west to join previous alignment.
Becomes M1 motorway between junctions 22 and 24A. Used to start at Hockliffe on A5, north of Dunstable. Gradually cut back to Northampton, then Leicester. Before opening of Derby southern bypass in 1997, it followed present A511 between Markfield and Foston.
Formerly ending at the A5 in Tamworth, the road to the south was the northern end of the A423. When the latter was downgraded north of Coventry, the A51 was extended to the A47. Subsequently the A47 too was downgraded (to the B1114) and the A51 was then cut back to its present terminus near Kingsbury.
Known locally as the D Road, either because its route resembles the curved part of a letter D (with a section of the M6 forming the upright) or after the Roman numeral 'D' (500)
This became part of the A52 (except for the spur in Leek; the current route of the A52 west of there was the A524 at the time), but the changes were undone almost immediately.
Was a road from Swinscoe to Newcastle-under-Lyme (formerly part of the A52). This almost immediately became part of the A52 again, as the old route of the A52 reverted to the previous designation of A523. Previously was a road from Fenny Bentley to Great Rowsley (now B5056).
Follows the course of one of the historic "Salt ways" that ran from Nantwich into Wales. Part of its central section, between Broxton and Bickerton Hill, is still called 'Salters Lane'.
Referred to sections of the upgraded A50 (e.g. from Foston to Etwall) before the A50 was rerouted; the original A564 went from Liverpool to A567/Bridge Road (now A567).
Commences at the junction of Finchley Road and Hendon Way on the A41. It goes through Golders Green and crosses the A406 and A1 at Henlys Corner, then heads through Regents Park Road to the centre of Finchley and Ballards Lane up to Tally-Ho Corner where it terminates on the A1000
The section of Hendon Lane north of Gravel Hill. Originally all of Hendon Lane and the A504 to the West of it was part of the A5000, although some old maps have the A5000 ending at the west on the A502, with that number taking over the remainder.
Ran from Macclesfield to Whaley Bridge (now B5470); formerly continued south to Buxton via what is now the A5004. Previously allocated to a road from A6 to A510 in Finedon via what is now Obelisk Road.
Number for the former A6 between Buxton and Whaley Bridge. Previously allocated to a road from Station Road to B5010 via Donington Lane north of Castle Donington.
Ran from Church Street (then A5039) via Ranelagh Street to A5038 in Liverpool, with a spur on Great Charlotte Street; the section west of Great Charlotte Street is now the B5339 while the remainder is probably now part of the A5038 (but still shown as the A5044 on the OS map).
Formerly part of the A45 road. The northeastern section was numbered A4508 (A45-A508 link) until the mid 1990s, when the route was renamed A5076. Previously allocated to a road from the A6 via Stricklandgate in Penrith; this became part of the A6 in a one-way pair.
Commonly referred to as the Princess Parkway, although this name only applies to the section between the M60 and the M56. The A5103 between the M60 and the city centre is actually Princess Road.
Previously allocated to a road on Fullhurst Avenue, Braunstone Avenue, Wyngate Drive, Woodville Road, Henley Road, Fosse Road, Blackbird Road, and Abbey Park Road (now B5327) from Braunstone to Abbey Park.
Penwortham Bypass Flyover from A59 to A582 south of Preston; it is unknown if this road was actually signed or it was a planned route number that was never implemented.
Mostly split into two one-way streets, St Pancras Way and Royal College Street. Southern section used to meet the Euston Road but now runs along Goods Way.
Starts at junction of A4201 Albany Street, (Piccadilly Circus to Camden Town via Portland, Fitzrovia) goes via the A41 Park Road Junction (A41 Wellington Road) as the Prince Albert Road, and then continues to the A5 at Maida Vale as St. John's Wood Road. The road can be used as a northern bypass to the London Inner Ring Road between the Edgware Road and Great Portland Street section, and is often a much faster route than the A501 in this section.
Was a proposed road from M6 at Orrell to M61; this scheme was withdrawn in 1996. Later proposed for a road from M6 to A579; this scheme was withdrawn in 2007. A proposed road from the A49 to the B5238 in Wigan started construction in 2018, and will later extend west to the M6. It is unknown if the road will be given this number or not.
Known as the Squires Gate Link Road, this links the M55 with Blackpool Airport and the southern end of the Promenade. Partly follows former alignment of Blackpool Branch Line.