Clear zone
Clear zone - the total roadside border area starting at the edge of the traveled way, available for safe use by errant vehicles. This area may consist of a shoulder, a recoverable slope, a non-recoverable slope, and/or the area at the toe of a non-recoverable slope available for safe use by an errant vehicle. The desired width is dependent upon the traffic volumes and speeds, and on the roadside geometry. The current edition of the AASHTO Roadside Design Guide should be used as a guide for establishing clear zones for various types of highways and operating conditions. This publication is available for inspection and copying from the FHWA Washington Headquarters and all FHWA Division Offices as prescribed in 49 CFR part 7. Copies of current AASHTO publications are available for purchase from the American Association of State Highway and Transportation Officials, Suite 225, 444 North Capitol Street, NW., Washington, D.C. 20001, or electronically at http://www.aashto.org.