Recently, in the United States, roundabouts have been used to replace signalized and unsignalized intersections because the use of
roundabouts has safely reduced crash severity and fatality at intersections by eliminating or altering conflict types and forcing drivers to
reduce their speed as they drive in and through it. Generally, in Florida, due to the recent introduction of roundabouts and the complexity of
some roundabouts (especially multi-lane roundabouts), drivers are most times not familiar with this type of intersection and therefore involve
in a crash. Therefore, it is necessary to evaluate the safety effects of roundabout amongst drivers and especially aging drivers since it is
projected by the United States Census Bureau, that the population of persons aged 65 and above in Florida is expected to be more than 26% of the
total population by the year 2025 and by the year 2030 all the baby boomers will be older than age 65. Thus, the objectives of this study were
to evaluate the effectiveness of roundabouts among drivers by comparing the crash severity of roundabout crashes involving aging drivers versus
their young and middle-aged counterparts and to determine the relationship between the crash frequency, the geometric characteristics of
roundabouts and the signage of roundabouts .In order to achieve these objectives, the type and severity of roundabout crashes, as distributed
according to participant age will be investigated Binomial logistic regression model was used to evaluate injury severity differences in
roundabout crashes amongst drivers of different age groups while evaluating the differences in factors relating to roundabout crashes which
includes the time of the day, day of the week, the type of roundabout, weather conditions, lighting conditions, the geometric design of the
roundabout, vehicle speed and the crash's at-fault driver age. Also, the negative binomial regression model was used to determine the
relationship between the total number of crashes, the roundabout speed, the geometric conditions and signage of the roundabouts selected for the
count study. The results from this study indicate that vehicle speed and average annual daily traffic are the most important factors affecting
the severity of crashes among all age groups at roundabouts and that the total number of crashes on roundabouts are affected by the traffic
volume, the number of circulatory roadway lanes, the number of legs, the roundabout speed, inscribed circle. diameter, and the presence of
signages and signals such as chevron, pedestrian sign, approach marking, lane use control symbol marking and pavement word. For aging drivers,
the number of vehicles involved in the crash, the vehicle speed of the at-fault driver and the type of crash are significant at 95% confidence
interval in affecting their crash severity while the annual average daily traffic is the only significant factor at 95% confidence interval
affecting the frequency of aging driver crashes at roundabout This study focuses on developing recommendations for roundabout implementation,
improved design guidelines and additional recommendations for improved for improved safety of drivers in the State of Florida. / A Thesis submitted to the Department of Civil and Environmental in partial fulfillment of the requirements for
the degree of Master of Science. / Fall Semester 2018. / November 26, 2018. / Includes bibliographical references. / Lisa K. Spainhour, Professor Directing Thesis; Eren E. Ozguven, Committee Member; Maxim Dulebenets,
Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_661117 |
| Contributors | Adegbulugbe, Oluwanifemi Tomilayo (author), Spainhour, Lisa (professor directing thesis), Ozguven, Eren Erman (committee member), Dulebenets, Maxim A. (committee member), Florida State University (degree granting institution), FAMU-FSU College of Engineering (degree granting college), Department of Civil and Environmental Engineering (degree granting departmentdgg) |
| Publisher | Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text, master thesis |
| Format | 1 online resource (80 pages), computer, application/pdf |
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