The basic objective of this guide is to help engineers, planners, environmental specialists, and road managers make good decisions, protect the environment, and build good low-volume roads. Key issues that should be addressed when planning a road project include changes or negative impacts to the area that a road can cause which may be significant, irreversible, or difficult to mitigate. The producing, purifying, and maintaining clean water. Roads must protect water quality and the biotic environment that depends on it.