Arlary Junction

The temporary motorway terminal in 1973. The motorway ended where the thick edges on the through road stop

Before the junction was constructed in 1960. The then-A90 was along the line of the present-day M90

Arlary Junction is junction 8 of the M90, connecting to the A91 to the north east of Milnathort. It was built in 1971 and between 1972 and 1977 it formed a temporary terminus for the M90, with the road spontaneously becoming the A90 just north of the present-day junction. This location can be seen today as it is the point where the M90's hard shoulder disappears (or reappears, depending on the direction of travel). The A90 was the rebuilt as a motorway, the difficulties of threading the route through Glen Farg to the north leading to the lengthy delay between opening dates.

The junction is a limited access fork, where the only connections available are west facing slips on the M90 leading to and from the A91 which is in a multiplex to the west of the junction (with either the M90, or the B996, depending on your way of thinking). There is therefore no connection between the motorway and the B996, nor any north east facing slips on the motorway. The only movements therefore permitted are, eastbound from the M90 onto the A91 and westbound from the A91 onto the M90.

All of the other movements are provided either at Hilton Interchange on the far side of Milnathort, which is also limited access with north/east facing slips only; or at the full access Muirmont Junction at Bridge of Earn on the far side of Glen Farg. The junction, and Hilton Interchange, were specifically designed as limited access in this manner as it was intended that they would primarily only serve long distance A91 traffic, with all local traffic using other routes. However, since the motorway opened, the volume of long distance traffic, particularly heavy traffic, on the A91 has declined as other routes have been improved and offer better alternatives.

History

Prior to the coming of the motorway, the A90 travelled through the junction site along the line of the present-day M90, while the A91 continued along the modern route of the B996 towards Milnathort. The B919 crossed the A91 to meet the A90 a short distance to the east, with the A90 then following the B996 route north. Meanwhile, to the west of Arlary where the B996 and M90 are currently alongside each other, the A90 and A91 met at a fork, and then multiplexed west into Milnathort for nearly a mile.

Routes

Route	To	Notes
M90	Aberdeen, Dundee, Perth	access only to/from M90
M90	Forth Road Br., Kincardine Br.
A91	St Andrews, Glenfarg
B996	Milnathort	access only to/from A91