The A7 will be closed at Crookston from the B6368 Gilston junction south to Hazelbank Quarry, north of Fountainhall from 20 March 2017 to 22 March 2017 between the hours of 09:00 and 16:00 each day and at Falahill from the bus layby at Falahill north to the Midlothian boundary from 23 March 2017 to 24 March 2017 between the hours of 09:00 and 16:00 each day.
The alternative route is via the A7, A6091, A68, A6106, A6094 and the A7 to the point of closure.
More details.
I expect there will be a lot more traffic on the old coach road.