@article{ref1,
title="Technique for Identifying Problem Downgrades",
journal="Journal of transportation engineering",
year="1983",
author="Eck, RW",
volume="109",
number="4",
pages="604-610",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0733-947X",
doi="",
url="http://dx.doi.org/"
}