Transcript PowerPoint Module 1 Introduction to Roundabouts

Roundabouts in the United States
Module 1
A Nationally Emerging Practice
Introduction to Roundabouts
Traffic Engineering
PHOTOGRAPHY SOURCE: David Plazack
Traffic engineering principles are well rooted in history.
Sometime in the early 1800’s traffic management became an issue.
Roundabouts in the United States
Module 1—Introduction
Intersections
Intersections have always been a primary concern for transportation
professionals.
As traffic volumes increase, configuration of the intersection can be
modified to accommodate traffic.
Roundabouts in the United States
Module 1—Introduction
Intersection Traffic Control
Early forms of intersection traffic control required
the presence of a human operator.
Traffic signals and pedestrian activated devices have become the
preferred method to manage traffic through intersections.
Roundabouts in the United States
Module 1—Introduction
Circular intersections
Circular intersections have been used in this country in the past.
PHOTOGRAPHY SOURCE: United States Geographic Survey
Dupont Circle, Washington DC
Roundabouts in the United States
Module 1—Introduction
Roundabouts: An alternative
PHOTOGRAPHY SOURCE: Lee Rodegerdts
The roundabout is yield controlled, traffic flows with fewer stops.
Air quality also benefits when motorized traffic is kept in motion.
Roundabouts in the United States
Module 1—Introduction
Roundabout Rules of the Road
The rules for traveling through a roundabout are easily explained and
will eventually be included in most state driver’s manuals.
Special brochures also introduce these new additions to the public.
Roundabouts in the United States
Module 1—Introduction
The Future of the Modern Roundabout
As safety and environmental advantages become recognized,
roundabouts will be adopted by transportation professionals just like
other technological advances.
Photo: Maryland SHA
Roundabouts in the United States
Module 1—Introduction