@article{ref1,
title="Notes on the relationship between headways and traffic flow",
journal="Public health reviews",
year="1987",
author="Hirsch, M.",
volume="15",
number="4",
pages="311-313",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0301-0422",
doi="",
url="http://dx.doi.org/"
}