The overall goal of this thesis was to provide a quantitative analysis of the operational and safety performances of roundabouts. The
operational analysis of Florida roundabouts was conducted to determine the base capacity of different configurations of approaching lanes.
Building upon the methodologies and findings of NCHRP 572 report, FHWA-SA-15-070 study and HCM 6th Edition, capacity models were calibrated to
reflect Florida driving conditions for different roundabout lane configurations. The results indicated that Florida roundabouts were not
congested, the gap acceptance parameters were within the range of the HCM 6th Edition with slightly higher average values of follow-up time. The
study found out that the HCM 6th Edition models generally overpredicted the capacity of roundabouts in Florida. Safety performances were
evaluated from the crash data of 34 roundabouts in Florida for a period of 5 years. The type of crashes, severity and contributing factors were
analyzed to determine the relationship between the roundabout crashes severity with traffic and geometric parameters. Four types of crashes were
found to be prevalent in the roundabouts (i.e. Rear-end, Angle, Sideswipe and Off-road crashes). The crashes were 77.4% PDO, 21.9% injury and
only 3 fatal crashes. Results indicated that the crash severity was influenced by the number of vehicles involved in the crash, and diameters of
the inscribed circle and central island. There was a 3.6 odds of a crash causing injury or fatality for an incident involving a single vehicle
than it was for an incident involving more than one vehicle. The negative binomial model was developed to show the relationship between the
total number of crashes at a roundabout with the traffic exposure, geometric, age, gender and weather parameters. The traffic volume (i.e. AADT)
and inscribed circle diameter were significant variables in the proposed safety models at a 95% level of confidence. Generally the roundabouts
were found to have few crashes consistent with the results from other studies. / A Thesis submitted to the Department of Civil Engineering in partial fulfillment of the requirements for the
degree of Master of Science. / Fall Semester 2018. / October 26, 2018. / OPERATIONS, ROUNDABOUT, SAFETY / Includes bibliographical references. / Ren Moses, Professor Directing Thesis; Eren Erman Ozguven, Committee Member; Maxim Dulebenets, Committee
Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_661152 |
| Contributors | Kadeha, Cecilia Fabian (author), Moses, Ren (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 (87 pages), computer, application/pdf |
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