A great potential use of the shaped rocks system lies in additional road graphics. They should appear more refined than the standard paved roads currently in game. Advanced roads could give a very minor speed boost over current paving, or merely be a visual bonus for players.
When building these specialty roads, the ground should be raised by 2 units. As each shaped rock requires 20 of the resource, I am suggesting that no more than 10 should be required for each section of road.
This would give three new road options, which could be listed under the drop menus (similar to how paving does now) as follows:
Masonry: Build road.
Architecture: Build Granite road.
Build Marble road.
I would also suggest a primitive road, which would appear under construction materials preparation. This would be a simple set of wooden boards or sticks across the ground. I am thinking 5 wooden boards, of 25 sticks, to construct a section of this primitive pathing. Obviously this should be no better than a clay road... maybe even only providing a 5% speed boost.
Additionally, to make the area around buildings look nice, it would be awesome to be able to build on top of flat roads. Paving doesn't improve visuals too much, but for a high end city having good roads which go right to building edges would be great (obviously players would have to plan if they are not making the foundation in full, as edge height would go up with this system.)