Carstairs Junction

The use of this road number in this location is currently disputed, because:

No official name found for this junction, not to be confused with the nearby village at the railway junction

Carstairs Junction is the junction of the A70 and the A721 to the north of Carstairs Village. The A70 heads north from the village to meet the A721 and then TOTSOs right as the two route multiplex through to Carnwarth. The current layout has a very wide bellmouth, with plenty of room for turning traffic, and a right turn lane from the A721, however, the layout used to be very different.

A short distance to the west, the A721 climbs up through a notch in a low ridge, constraining the approach to the junction. However, it would appear that it originally curved round to the south in the field to meet the A70 near the closed-up driveway to Columbie Farm. The old line of the A70 can be traced on the opposite side of the small field. A tie across between these two arms already existed in the 1850s on the first OS Six Inch Map, but it seems likely from the geometry of the old junction that this was a later addition, probably built by the turnpike commissioners. This tie in was a short distance to the south of the current main line, and can be approximately identified as the eastern junction survives in the field. The junction survived in this form until at least the 1970s, at which point it was remodelled to something more closely resembling the current layout. The junction was rebuilt again in 2015.

The intermediate design included three traffic islands, segregating all of the turning movements, with slow down and acceleration lanes for traffic turning in and out of Carstairs. The crash barrier to the east still follows the line of the slow down lane, now replaced by a wide pavement, while the pavement to the west used to be roadside, a wide grass verge now separating them. The right turn lane in the centre of the junction has survived more or less unchanged. The new pavement to the east, incidentally, extends as far as the old alignment of the A70, where it comes to an abrupt end. While these changes have probably improved the junction for traffic, it is a little more daunting to navigate for pedestrians and cyclists, without the protection and refuge of the traffic islands.

Routes

Route	To	Notes
A70	Carstairs, Lanark, Ayr, New Lanark
A70	Carnwath, Edinburgh, Peebles (A721), State Hospital
A721	Carluke, Glasgow (A73)