There is no M7 motorway primarily because the A7 road, which it would have been intended to replace, was not considered significant enough to warrant a motorway upgrade.
In Scotland, where many motorways were constructed, the numbering system often followed that of existing A roads. The design philosophy was for new motorways to supersede or run parallel to these older routes, improving traffic flow and capacity. A prime example of this approach is the M8 motorway, which largely replaced the earlier A8 road.
Following this established pattern, an M7 motorway would logically have been the designated successor or parallel route to the A7. However, unlike other major arterial routes, the A7 was not assessed as having the traffic volume or strategic importance that would justify the substantial investment and infrastructure required for a motorway. As a result, plans for an M7 were never pursued, leading to the absence of this particular motorway in the network.
