Thaks to all who replied. these tips helped point us in the direction we may take. That is:
1 - Dig a 2' x 6" deep trench in the center
2 - Line the trench with a rubber liner
3 - Add 4" of gravel
4 - Close the top with 2" of Flexi-Pave (an extremely porous sphalt substute).
This should...
It Isn't a freeze thaw problem (we're in Central Florida).
Since the land is relatively flat, and the roads have a reverse crown, the water tends to collect in small pools at the roads center. Traffic passing through these wet spots evventually causes pot holes. The comment re how the lanes...
The asphalt in the middle of a reverse crown road (center drains)wears out and develops potholes (erosion?) in too short time. Is there a solution or road modification to help this problem?