Pre-1977 The Great North Road and later the first incarnation of the A1 passed directly through Low Fell, Gateshead, Newcastle upon Tyne, Gosforth and Wideopen before rejoining the current A1 at Seaton Burn. The Great North Road was effectively diverted from the Swing Bridge to the Tyne Bridge when it opened on 25 February 1928, the A1 passing up Pilgrim Street and Northumberland Street. The later first incarnation of Newcastle's Central Motorway built during the 1970s and passing just to the east of Newcastle City Centre, was initially numbered A1. The portion of Great North Road through Gateshead and Newcastle has had a number of designations since it ceased being the A1 in 1977. Between 1977 and 1993, it was numbered A6127 between Birtley and Newcastle and A6125 between Newcastle and Seaton Burn—both road numbers are now redundant. Since 1993, the Birtley to Newcastle section has formed part of the A167 and the Newcastle to Seaton Burn A6125 section has been the B1318. 1977 to 1993 After the opening of the Tyne Tunnel on 19 October 1967, the main route for traffic around Gateshead and Newcastle was diverted to the east. With completion of the A1 through County Durham in the 1970s, from 1977 onward the A1 ran as the A1 from Birtley past the north of Washington to the Newcastle Road / Leam Lane junction near Wardley. It then ran east to Testo's Roundabout near West Boldon, following what is now a section of the A184. At Testos Roundabout, the A1 turned north following what is now the northern section of the A19 towards Jarrow and the Tyne Tunnel. North of the Tyne Tunnel, the A1 passed through Howdon, before it continued in a north-westerly direction, through North Tyneside past Killingworth and Cramlington, rejoining the current A1, just north of Newcastle at Seaton Burn. Again, this section of road has been redesignated A19. The section of road now forming the A19 between Testo's Roundabout and Seaton Burn was numbered the A108 prior to it being numbered the A1 then A19 as detailed above. 1993 onwards The A1 officially assumed its western route in 1993, with completion of the Newcastle Western Bypass and opening of the Blaydon Bridge on 3 December 1990. The Gateshead Western Bypass, forming the southern part of this western route, was renumbered from A69 to its current A1 number.
Historically, the A1 followed its current route to just north of Boroughbridge, then following the route of the current A168 at Dishforth to Topcliffe from Dishforth to Birtley. The Dishforth to Barton section was dual carriagewaytrunk road numbered A1 until the Dishforth to Leeming section was upgraded to motorway in 2012, with the Leeming to Barton upgrade finally being completed in 2018.
