@article{ref1,
title="Field and laboratory evaluation of roadside sign surfacing materials",
journal="Highway Research Board bulletin",
year="1951",
author="Havens, James H. and Peed, Allie C.",
volume="43",
number="",
pages="32-44",
abstract="Physical and optical characteristics of sign materials and design and application of a reflectometer devised by the Kentucky department of highways are discussed. Accelerated weathering procedures and specification standards are described. Field studies paralleling laboratory work and a possible correlation between the two are described. The field work included several thousand individual observations covering 30 different sign-surface types under actual conditions on a night-visibility driving-course. Most of the major types of surfaces available were represented. In addition to using ordinary sealed-beam headlamps, field observations were made using polarized headlamps and viewers.<p />",
language="en",
issn="0073-2206",
doi="",
url="http://dx.doi.org/"
}