A relatively young and ambitious ruler has decided to build roads across the domain as part of a large public works project. The dirt tracks and existing gravel roads are to be paved with local stone where possible and fired clay bricks in places where transporting stone is prohibitively expensive. These roads are in relatively flat terrain linking three large cities on the borders to the capital which is in a central location within the realm.
The three cities have large but largely immobile forces of foot infantry anchoring the borders, while the ruler's forces in the capital are mobile cavalry and elite well equipped infantry units small enough to be transported in horsecarts. The sluggish nature of the large border city infantry hosts makes it hard for any of the three cities and their lords to rebel and march against the capital, where the more mobile capital army can harass them to death in-transit. At the same time the equine-centric army is quick in reinforcing any border city in case of external invasion.
How would long term transit on solid paved roads affect the horseshoes of this vital cavalry heavy contingent? Stone or brick is harder than gravel or dirt, with allows wheels to go faster which is the allure of such infrastructure. If the new roads also increased or decreased wear on the horseshoes or the mounts themselves, it would likely have a large impact on the feasibility of consecutive deployments of the capital army.
The type of road being laid is not the object of the question. I know many of the people on stack exchange are super enthusiastic about road laying, but the type of road has been set and will not be changed to be the perfect dream infrastructure because it doesn't fit the story.