Date of Award


Document Type


Degree Name

Master of Science (MS)

Legacy Department

Civil Engineering

Committee Chair/Advisor

Ogle, Jennifer H

Committee Member

Sarasua , Wayne A

Committee Member

Chowdhury , Mashrur A


The state of South Carolina has experienced a large number of fatalities and injuries resulting from run off the road tree related crashes. According to 2008 FARS data tree related fixed object fatal crashes in South Carolina (65%) are more than double that of the national (25.8%). Thus, trees are much bigger proportion of all roadside hazards in South Carolina than nationally. In order to achieve a safer roadside which is favorable to the road user, factors contributing to the tree related crashes should be critically analyzed to determine suitable safety improvements.
This research aims at qualitatively and quantitatively assessing tree related crashes in SC and performing an in depth study of the problem to determine potential countermeasures to increase safety of the roadside environment. Various descriptive statistics were computed to determine any significant contribution of crash characteristics using the police accident reports database obtained from SCDOT from the years 2004 to 2006. Detail analysis of clear zone adequacy and possible slope issues were performed using the roadside inventory data collected from 'Support for Elimination of Roadside Hazards' project.
The analysis revealed that tree related crashes in SC were predominantly related to young male drivers, secondary roads and speeding. Over a large portion of fatal crashes involved young male drivers speeding under the influence of alcohol/drugs during poor visibility or dark conditions. Clear zone adequacy analysis revealed that majority of the sites did not meet minimum clear zone requirements indicating, if a tree-crash pattern exists, it is likely that minimum clear zones are not met. A larger part of the sites analyzed had traversable side slopes and clear zone width was the only problem.



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