Port Dundas Interchange

The Port Dundas junction on the M8 was the proposed link between the M8 and the Maryhill motorway or M81 as it would probably have been numbered. This route was never built, but in preparation the M8 was built to allow for it to be connected in in the future. Therefore, we have a fairly clear idea of what this junction would have looked like.

The westbound carriageway of the M8 has the clearest evidence for what might have been, with the right-hand off slip still there, coned off, and heading under the eastbound carriageway to terminate in vegetation on the edge of the canal basin. Indeed, it is the route of the canal branch that would have been most likely used for the M81 in order to minimise destruction. Further west, a tiny stub shows where the right-hand onslip would have been located, although such a sliproad would have produced significant weaving problems for any traffic wishing to leave at Junction 17 to join the A82.

Heading east, the offslip is less obvious as it has been hidden behind a continuous barrier. Again just a tiny stub, it diverges immediately after the motorway crosses the terminus of the A81. The corresponding onslip is even harder to identify, but would almost certainly have been located where the hard shoulder starts under the gantry alongside the canal basin. Both slips are on the traditional lefthand side.

Put together this junction would have been the only true Directional T junction to be built in the UK, but alas it was not to be!

Routes

Route	To	Notes
M8	Kilmarnock (M77), Greenock
M8	Edinburgh, Stirling (M80), Carlisle (M74)
M81	Aberfoyle (A81), Dumbarton (A82)