TY - JOUR
T1 - Effect of traffic roundabouts on accident rate and severity in Arizona
AU - Mamlouk, Michael
AU - Souliman, Beshoy
N1 - Funding Information:
This project was partially funded by the National Transportation Center @ Maryland (NTC@Maryland), one of the five National Centers that were selected in this nationwide competition, by the Office of the Assistant Secretary for Research and Technology (OST-R), U.S. Department of Transportation (US DOT). The cost share contributed by Arizona State University is greatly appreciated. Appreciation is also given to Paul Basha, Andrew Merkley, and George Williams of the City of Scottsdale, AZ; Roxanne Holland of the City of Sedona, AZ; and Kerry Wilcoxon of the City of Phoenix, AZ.
Publisher Copyright:
© 2018, © 2018 Taylor & Francis Group, LLC and The University of Tennessee.
PY - 2019/7/4
Y1 - 2019/7/4
N2 - Although roundabouts have been used at many locations around the world, the safety of roundabouts under different conditions has not been fully understood. In this study, 17 roundabouts in five cities in Arizona were evaluated, out of which 11 are single lane and six are double lane. Most of the intersections of single-lane roundabouts were controlled by two-way stop signs before roundabout conversion, whereas most of the intersections of double-lane roundabouts were controlled by traffic signals. Accident data were collected and broken down into five categories: damage without injury, minor injury, nonincapacitating injury, incapacitating injury, and fatality. Equal number of years were used before and after the roundabout conversion at each location. The average rates of accidents, damages without injury, injuries and fatalities per year and per million vehicles were evaluated. It was found that single-lane roundabouts reduced the accident rate, whereas double-lane roundabouts increased the accident rate. The results also showed that single- and double-lane roundabout conversions reduced the severity levels of accidents. Considering accident rate and severity level, warrants need to be developed for roundabout conversion and number of roundabout lanes under different traffic conditions.
AB - Although roundabouts have been used at many locations around the world, the safety of roundabouts under different conditions has not been fully understood. In this study, 17 roundabouts in five cities in Arizona were evaluated, out of which 11 are single lane and six are double lane. Most of the intersections of single-lane roundabouts were controlled by two-way stop signs before roundabout conversion, whereas most of the intersections of double-lane roundabouts were controlled by traffic signals. Accident data were collected and broken down into five categories: damage without injury, minor injury, nonincapacitating injury, incapacitating injury, and fatality. Equal number of years were used before and after the roundabout conversion at each location. The average rates of accidents, damages without injury, injuries and fatalities per year and per million vehicles were evaluated. It was found that single-lane roundabouts reduced the accident rate, whereas double-lane roundabouts increased the accident rate. The results also showed that single- and double-lane roundabout conversions reduced the severity levels of accidents. Considering accident rate and severity level, warrants need to be developed for roundabout conversion and number of roundabout lanes under different traffic conditions.
KW - crash data
KW - infrastructure design
KW - operation
KW - roundabouts
KW - traffic injury
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U2 - 10.1080/19439962.2018.1452812
DO - 10.1080/19439962.2018.1452812
M3 - Article
AN - SCOPUS:85045692239
SN - 1943-9962
VL - 11
SP - 430
EP - 442
JO - Journal of Transportation Safety and Security
JF - Journal of Transportation Safety and Security
IS - 4
ER -