Engineering Commons^™

Establishing Delay-Based Criteria For Installing Traffic Signals At Two-Lane Roundabouts, Oluwaseun Ayomide Adegbaju

Masters Theses

A roundabout is a circular intersection where drivers travel counterclockwise around a center island in the United States. Roundabouts can be more beneficial than the conventional intersections because they increase the capacity of the intersection and reduce delays and crashes at the intersection. However, the performance of roundabouts can be severely affected by unbalanced traffic flows among the approaches. While the resulting delays can be mitigated by installing traffic signals, there is a lack of clear criteria on when to install a traffic signal at a roundabout. This research focuses on establishing criteria for installing traffic signals at two-lane roundabouts …

Virtual Analysis And Evaluation Of Roundabout Safety And Operational Features, Elisha Jackson Wankogere

Masters Theses

Roundabouts can be a solution to safety concerns present at other types of intersections. Recently in the United States, there has been an increase in conversion of problematic intersections to roundabouts to improve their safety. However, it is difficult to make these roundabouts, especially multi-lane roundabouts, safe to all ranges of users. Roundabout features such as advance warning and signage play an important role in determining driver performance as they navigate the roundabout.

This research is an effort to evaluate new and existing roundabout safety and operational features such as signs and pavement markings and how they influence performance of …