|Location Map ( geo)|
|From:||Olrig Street (ND114682)|
|To:||Thurso Station (ND112679)|
|Distance:||0.3 miles (0.5 km)|
|Met (1923):||A88, Station yard|
|Now part of:||B874|
|Route outline (key)|
The A840 was a short branch from Thurso town centre (initially Sir John's Square, on the original route of the A88) down to the railway station along Princes Street. In 1922, the continuation of this road along Ormlie Road was unclassified but later in the 1920s it was numbered B874. Aside from the A88, the A840 was the only 'A' road originally allocated in Caithness in 1922.
The A840 is not explicitly mentioned on any road maps after the 1920s, although it is always shown as an A-road. However, the OS 1:10,000 sheet from 1960 marks the A840 as running the full length of Princes Street from the A882 (which replaced the A88 in 1935), Olrig Street down to the Station forecourt, where the B874 takes over. By the 1967 sheet the A840 has gone, and the B874 extended north to Sir John's Square, which is now part of the A882, so also displacing the A8002. Princes Street is also shown as being part of the extended B874 on the 1968 OS One Inch map, and remains as such today.