@article{ref1,
title="Efficacy of jurisdiction-wide traffic control device upgradings",
journal="Transportation research record",
year="1986",
author="Lyles, Richard W. and Lighthizer, Dale R. and Drakopoulos, Aris and Woods, Sandra",
volume="1068",
number="",
pages="34-41",
abstract="An evaluation of several jurisdiction-wide traffic control device upgradings in Michigan was undertaken. The upgradings included only signs. A &quot;before-after with control&quot; experiment design was employed in the examination of general accident distributions along with a more detailed distribution of vehicle-vehicle accidents. <br><br>RESULTS of assessing the overall effectiveness of traffic control device (TCD) upgradings on a jurisdiction-wide basis were mixed at best. Due to the general variability of accident statistics and because most sites in a jurisdiction have only minor, if any, problems, potential positive results tend to be overwhelmed at sites where there may be significant improvements. It is suggested that safety-effectiveness studies are more appropriate at lower levels of aggregation.<p /><p>Language: en</p>",
language="en",
issn="0361-1981",
doi="",
url="http://dx.doi.org/"
}