@article{ref1,
title="A 30-foot clear zone concept - a guide, not a standard",
journal="ITE journal",
year="1988",
author="Olivarez, D.",
volume="58",
number="9",
pages="45-46",
abstract="It is noted that the term '30-foot clear zone,' although it is should be considered in design practice, should not be construed to be a fixed numerical design requirement. The concept should be considered a desirable guide depending on practical considerations of topography, finance, environmental impacts, and engineering judgment. The reasons for not establishing the concept as a standard are discussed.<p />",
language="",
issn="0162-8178",
doi="",
url="http://dx.doi.org/"
}