@article{ref1,
title="Impact of speed limits and road characteristics on free-flow speed in urban areas",
journal="Journal of transportation engineering",
year="2016",
author="Silvano, Ary P. and Bang, Karl L.",
volume="142",
number="2",
pages="e04015039-e04015039",
abstract="The paper documents studies of posted speed limit (PSL) changes on the free-flow speed on urban roads. Before and after field measurements were conducted, changing the existing PSL from 50 to 40 or 60 km/h. The analysis was conducted on the mean free-flow speed difference and speed variability. The data collected were also used for multiple regression analysis, including PSL changes and selected self-explaining road characteristics. The results showed that a decreased PSL caused a small (1.6 km/h) but significant reduction in the mean free-flow speed and speed variance, which might lead to a 10% reduction of severe injury accidents. Furthermore, the PSL reduction had a larger impact on faster drivers and higher road network classes. Conversely, an increased PSL resulted in a 2.6 km/h increase in the mean free-flow speed but no change on speed variability. The regression results indicated that the free-flow speed was heavily influenced by road characteristics, such as carriageway width, road environments, and the presence of on-street parking and sidewalks. Arterial roads presented the largest impact. The PSL had a relatively small impact.<p /> <p>Language: en</p>",
language="en",
issn="0733-947X",
doi="10.1061/(ASCE)TE.1943-5436.0000800",
url="http://dx.doi.org/10.1061/(ASCE)TE.1943-5436.0000800"
}