@article{ref1,
title="Optimal and minimal luminance characteristics for retroreflective highway signs",
journal="Transportation research record",
year="1985",
author="Sivak, Michael and Olson, Paul L.",
volume="1027",
number="",
pages="53-57",
abstract="Presented in this paper are optimal and minimal sign luminance recommendations based on a review of available applied research. Optimal recommendations are based largely on peak luminance-legibility relationships. In the absence of other criteria, minimal recommendations are based on performance levels of 6 m/cm (20/23) for younger persons and 4.8 m/cm (20/29) for older persons. By using a computer sign legibility model, calculations were then made to determine the photometric characteristics of signing material required to obtain the values indicated.  Record URL:  http://onlinepubs.trb.org/Onlinepubs/trr/1985/1027/1027-011.pdf<p /><p>Language: en</p>",
language="en",
issn="0361-1981",
doi="",
url="http://dx.doi.org/"
}