Gravel Roads Construction and Maintenance Guide - Federal .The original "Gravel Roads Maintenance and Design Manual" was . invaluable resource for managing gravel surfaced roads throughout the .. the process.process of gravel,Gravel - Products & services¾" & 1 ¼" Process Gravel – This material consists of ¾" or 1 ¼" stone, stone dust and a sandy gravel. It gives the look of a dirt road. Some of the towns use this.
process of gravel