|From:||Sir John's Square (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 (specifically 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 maps after the 1920s, although it is always shown as an A-road, so it is not clear whether the A840 survived until being downgraded in the 1960s, or whether it became a spur of the A882 (which replaced the A88 in 1935). The road is certainly shown as being part of the extended B874 on the 1968 OS One Inch map, however, and remains as such today.