Scotstoun Junction

This article is about the M90's current Junction 1.
For the M90's original junction 1, which has become Junction 1C, see Admiralty Junction.

The merge in 2007

Scotstoun Junction connects the southern part of the M90 to the A90 to the south of Queensferry. It is a limited access fork junction allowing traffic from Edinburgh approaching on the A90 to merge into the motorway traffic, although the onward route is, for complex reasons, still numbered as the A90. There is no link between the motorway and the A90 to/from Edinburgh. The junction opened in September 2007 with the extension of the M9 spur from Kirkliston, which had formerly terminated at a roundabout on the former A8000. The extension to the spur therefore removed a substantial bottleneck on the local roads network. The whole spur was then renumbered as part of the M90 in 2013, well in advance of the opening of the Queensferry Crossing in 2017.

With the opening of the bridge, the M90 mainline was extended across the Forth, but didn't quite reach the spur due to the dubious legal arguments about providing routes for non motorway traffic. This could have been handled via the new slip roads which connect the A90 to the B800 and A9000, but these have been designated as bus lanes, and so cannot be used by learners or tractors, despite such vehicles still being permitted to cross the old Forth Road Bridge. In practice, it makes very little difference to the average road user whether it is the A90 or M90, but from a Sabristic point of view it is untidy.

With the opening of the Queensferry Crossing, two new sliproads were created to replace those lost at the Echline Junction. One leaves the A90 east of the merge and connects to the B800 and is for buses destined for the old Forth Road Bridge. This involves a fairly convoluted route through Queensferry itself to reach the Echline Junction. The other leaves the old A90 route from the Echline Junction, now the A9000, and runs alongside the main road to reach the A90, again east of the motorway split. This is also a dedicated bus lane. In order to accommodate the extra traffic lanes underneath, the old B800 overbridge was replaced in 2015.

Routes

Route	To	Notes
M90	Glasgow (M8), Airport (A8), Stirling M9
A90	Forth Road Bridge
A90	Edinburgh, Non-motorway traffic
A9000		from Forth Road Bridge
B800	Kirkliston, Scotstoun	to (A9000 Forth Road Bridge)
M9	Glasgow (M8), Airport (A8), Stirling