Print this page Roundabouts: Advantages and Suitability
Mark P. Rossow, PhD, PE Retired
Course Outline
This four-hour online course begins by defining the types of roundabouts being considered and then shows how roundabouts are distinguished from other traffic circles. Next the course provides a broad overview of the performance characteristics of roundabouts. The costs associated with roundabouts versus other forms of intersections, legal issues, and public involvement techniques are discussed. Finally the course discusses general guidelines for identifying appropriate intersection control options, given daily traffic volumes, and procedures for evaluating the feasibility of a roundabout at a given location. Sufficient detail to enable a transportation planner to decide under which circumstances roundabouts are likely to be appropriate, and how they compare to alternatives at a specific location are given.
This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.
Learning Objective
This course teaches the following specific knowledge and skills:
- Defining physical features and key dimensions;
- Distinguishing roundabouts from other circular intersections;
- Multimodal considerations;
- Costs associated with roundabouts;
- Legal considerations;
- Public involvement and education in the use of roundabouts;
- Planning steps for implementing roundabouts;
- Determining number of entry lanes;
- Types of roundabouts from which to choose;
- Comparing operational performance of alternatives; and
- Space requirements.
Intended Audience
This course is intended primarily for civil, construction, and highway engineers and planners.
Benefit to Attendees
A person completing this course will be familiar with and able to apply procedures for deciding if roundabouts are appropriate for a given intersection.
Course Introduction
The modern roundabout was developed in the United Kingdom to rectify problems associated with existing traffic circles. In 1966, the United Kingdom adopted a mandatory “give-way” rule at all circular intersections, which required entering traffic to give way, or yield, to circulating traffic. This rule prevented circular intersections from locking up, by not allowing vehicles to enter the intersection until there were sufficient gaps in circulating traffic.
Course Content
This course is based on Chs. 1-3 of the FHWA Report No. FHWA-RD-00-067, “Roundabouts: An Informational Guide,” June, 2000. The remainder of the report is provided as reference material.
Roundabouts: Advantages and Suitability
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Course Summary
This course provides information and guidance on roundabouts, resulting in designs that are suitable for a variety of typical conditions in the United States. The scope of the course is to provide general information, planning techniques, evaluation procedures for assessing operational and safety performance, and design guidelines for roundabouts.
Related Links
For additional technical information related to this subject, please visit the following websites or web pages:
http://www.nhi.fhwa.dot.gov/default.aspx
Quiz
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
