I believe either Peter Elstob ("Hitler's Last Offensive") or Charles B Mac Donald ("A Time for Trumpets", "Bastogne: The Roadblock") make the point that the road net, in general, runs NE to SW, which helped in 1940. In 1944, with Antwerp and Brussels being the objective, the Germans were advancing, at times, perpendicular to the better routes through the woods.
I doubt the allies took the time to do an analysis of the French campaign when suddenly faced with the German attack on 16 December. What made the US response so quick was, in part, the fact that the senior US commanders knew each other very well, having served together since WWI or even been classmates (or very close together in graduation years). This 'informal' means of transferring entire divisions worked so well that by the time the allied conference was held on 19 Dec, the German advantage in men and tanks had already been erased, even if the men and kit wasn't where it was needed (yet).
I have a few pics of the roads/terrain near Clervaux, Wiltz, La Gleize and Stoumont but attempts to upload have failed (too large, 1.27 mb)). This is strange because at another history site the same pics were automatically reduces to just a few dozen kb in the upload process.