Salmond's on record as saying they'd abide by an Aberdeen Western Peripheral Route inquiry rejection of the road, and hopefully the same applies here.
Patrick asked the question, and John Swinney answered it (I think) for Glenn Campbell. I'll see in a minute. The last lot had a shocking record on this kind of issue.
However, this also makes it much harder for Edinburgh's sleazy decisions over Caltongate to remain unchallenged. The local campaigners agree, and it's hard to see any inquiry there not demonstrating to a national audience the scale of opposition, the absurdity of the current plan, and the dubious financial practices of Labour in particular over this issue.