turned over the concept of a military clear zone before it hit me. But this is the JAG A.F. language.

Found using Google:

In the Heart of Darkness
... square miles of guerrilla territory, an area officially known as the zona de despeje (demilitarized zone), or the "laboratory of peace," but unofficially as ...
www.colombiareport.org/colombia20.html

This is what a clear zone is (in Spanish, zona de despeje) from the technical point of view:
The total roadside border area, starting at the edge of the travelled way, available for safe use by errant vehicles. This area may consist of a shoulder, a recovable slope, a non-recovable slope, and/or a clear run-out area. The desired width is dependent upon the traffic volumes and speeds, and on the roadside geometry.

hope it helps! :)