If you have the acreage for the horses to run on and you gradually work the horses on hard surfaces over time horse's hooves will become hardened to walking on rocky roads and pavement. Besides it being better for the horse, you save on the farrier which costs around $200 to shoe a team and they need to be shod several times a year. We have never trimmed these horses but have worked them gradually on the different road types. We learned about barefoot horse care on the INTERNET.
Here are some pics of how our draft horses have adapted.
Here is hoof that is well on the way to having the mustang roll i.e. the outer wall of the hoof on the bottom starts to round off
Here is what they look like today notice the hoof is pretty short and outer wall of the hoof in rounded off nicely in the toe.
The sole of the hoof is very hard now and they can go down rocky roads and pavement with no discomfort.