Actually, the Milan-Lakes autostrade did have comprehensive grade separation; no intersecting roads crossed them on the level. However, the bifurcations (where the spurs met the trunk route) were on the level, and the entry and exit points were reached by simple turns (including left turns across the centerline) rather than by ramps allowing gradual change in speed.Most of motorways opened in these years were not as we know today. But this one in particular is a new fast road built expressly for motor vehicles, it is not an older road built for horse carts and adapted later. There were not grade separated interchanges, for example, but it was straight, designed for speed.
The beginning of something beautifulReally, what was the point of that