01020691

Component

https://doi.org/10.3141/1931-13

http://scholar.google.com...ncan&publication_year=2005

The safety records of rural and suburban four-lane highways in Arkansas as a function of median treatment and access density were examined. The study excluded roadways with posted speeds lower than 64 km/h (40 mph) and excluded fully controlled access roadways. When entering an urban area, the segments were normally terminated when the first traffic signal or stop sign was encountered. By using 3 years of crash data, the analyses revealed a number of relationships relating crash frequency to median, volume, and access frequency attributes. Crash severity and crash type were also examined. As median width increased, there was a weak but statistically significant decline in the crash rate. There was a weak but statistically significant increase in the crash rate as access density increased. The roadways with shoulders and depressed medians had the lowest crash rates, and the roadways with no median (i.e., painted centerline) and curbs had the worst safety record. An inspection of these data suggests that there may be a correlation between median type and land use type: certain types of median are more likely to be present in certain land use environments. This raises the possibility that in this and in other studies of the safety effects of median treatments, the findings may be influenced or skewed by correlations between median type and land use or surroundings or by other factors.

01020675

English

pp 99-107

2005

Transportation Research Record: Journal of the Transportation Research Board

0309094054

Print

Figures (4) ; References (11) ; Tables (5)

Access; Center lines; Crash data; Crash rates; Crash severity; Crash types; Curbs; Four lane highways; Land use; Medians; Road shoulders; Rural highways

Depressed medians; Median treatments; Median width

Arkansas

Design; Highways; Safety and Human Factors; I20: Design and Planning of Transport Infrastructure; I81: Accident Statistics

TRIS, TRB, ATRI

Mar 24 2006 1:09PM

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