@article{ref1,
title="The design of automatic surveillance systems for urban freeways",
journal="Transportation research",
year="1968",
author="Altman, Stanley M. and Pignataro, Louis and Yagoda, Harry N.",
volume="2",
number="4",
pages="347-361",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0041-1647",
doi="10.1016/0041-1647(68)90101-9",
url="http://dx.doi.org/10.1016/0041-1647(68)90101-9"
}