[brudgers]

Depends on how far you have to move the cut to use it as fill. A few hundred meters probably isn't an issue. At a couple of kilometers transport becomes more of an issue than unloading.

For road building, transporting materials such as paving stones over long distances is an important consideration because roads are useful in places where local materials may not be suitable for quality construction. One might speculate that the Chinese wheel barrow's design helped bootstrap a network of roadways suitable for it's use.

Of course the upside of the collapse of Europe's road network may have been that it allowed localized development of the political structures upon which modern liberal states were developed.