The rerouting of the A1 via Scotch Corner in July 1924 was the first major change to the original allocation of road numbers just over a year earlier. It established Scotch Corner and Leeming Lane officially as part of the major arterial routes in the country.
Leeming Lane, the road from Boroughbridge to Scotch Corner, and part of the Roman Dere Street, had widely been recognised as the main route from England to Scotland for centuries. However, during the 18th century, the Great North Road, running to Darlington via Thirsk and Northallerton, had also become to be recognised as a practical coaching route, as it was slightly shorter and direct, and passed through more towns - an advantage for horsebound travellers compared to the rather sparse route further west.
The advent of the motor car, however, had reversed the situation somewhat, and consequently by the early 1920s, the wider and straighter Leeming Lane was generally considered to be the preferred route north. However, the MOT, reflecting the pattern seen elsewhere, frequently allocated main roads based on old coaching routes, and so the A1 originally ran via Northallerton, with the route to Scotch Corner instead being part of the A66 "Winter Route" to Penrith (and hence to Glasgow).
Almost immediately, the complaints rolled in. During 1922, highway division engineers in the North Riding, on viewing the draft allocation of road numbers, questioned why the A1 did not run via Scotch Corner. This opinion was further shared by other local authorities and businesses, who had become used to Leeming Lane being the main road.
In March 1924, a conference was held in Ripon, led by Colonel M J Wilson, MP for Richmond, to debate a way forward. Colonel Wilson also contacted Sir Henry Maybury, one of the key people in the MOT involved in road numbering, to advise when a conference with the MOT might be held.
The principal notes from the Ripon meeting were as follows :
This meeting is strongly of opinion that steps should be taken to have the road from Boroughbridge to Darlington, by way of Leeming Lane, restored as the A.1. road between London and the North on the following (among others) grounds, viz :
(a) That much valuable tourist traffic will be diverted from towns and villages of great historical interest, where provision is made for such traffic on or adjacent to Leeming Lane, and where, since the advent of the motor car, developments of an extensive character have taken place solely for the purpose of catering for the needs of the motoring public.
(b) That since the time of the Romans, Leeming Street has been recognised as the main artery of traffic between London and North Britain.
(c) The new route passes over roadways which are far less suitable for fast traffic, being narrow, having a tortuous course, and many dangerous corners, and will eventually have to be widened and strengthened at great cost, whereas Leeming Street takes a perfectly straight line away from populous districts, and nearly its whole length has sufficient verge to slice of its being widened.
(d) That Catterick Camp, as a large military centre, should be as near to the A.1. Road as possible on both strategetical and economic grounds.
After being firehosed with petitions similar to the above text, Sir Henry Maybury conceded on 26th May 1924 to meet with the local authorities and agree a way forward. This occurred on 8th July. In addition to Sir Maybury were Colonel Wilson, Major Edward Wood, MP for Ripon, and representatives of their respective councils.
The salient points of the meeting centred around the prohibitive cost to upgrading the Thirsk / Northallerton route, and the advantage of Leeming Lane being close to Catterick Camp.
The suggested renumbering was :
- A1 - Boroughbridge to Darlington via Scotch Corner
- A66 - Scotch Corner to Penrith
- A168 - Hull to Darlington via Boroughbridge and Northallerton
- A167 - Topcliffe to Northallerton
- A687 - (vacant)
Reflecting the strict zone rules of the time, it was pointed out that this would involve reallocating part of the 6 zone to the 1 zone, although, with one exception, it did not actually make any other roads (such as the A684 or B6267) out of zone. The sole exception was the B6273 between Scorton and the old A1, which took over the number B1263 from the Northallerton - Osmotherley road, which in turn became an extension of the A684.
In the event, there was one important alteration to the proposed scheme when the MOT agreed to implement the renumbering on 19th July. The road from Hull to Boroughbridge would not be an extension of the A168, but would instead receive a separate number. Since it ran entirely to the east of the A1, it would not have been able to re-use the soon-to-be-defunct A687, and so a new number was required. The annual renumbering revision that April had already allocated the A1065 to A1078 inclusive as reclassified B roads, so the next available number, the A1079, was used.