For citizens and commuters from neighboring suburbs, roundabouts result in numerous benefits, including increased safety, reduced traffic flow and fewer environmental impacts. Roundabouts cost less to maintain than traditional intersections and result in lower long-term costs for the City and its taxpayers.
A roundabout is a circular intersection through which vehicles travel counterclockwise around a center island. Traffic entering a roundabout slows to between 15 and 20 miles per hour and yields the right-of-way to circulating vehicles, which allows for smoother traffic flow and fewer delays. Bicyclists can also navigate easily through a roundabout and sidewalks are often installed on the perimeter for pedestrians.
In parts of the country where traditional intersections have been converted to roundabouts, motor vehicle crashes have been reduced by approximately 40 percent and injury crashes have declined by 80 percent, according to the Insurance Institute for Highway Safety.
The circular design of roundabouts helps to reduce right-angle, left-turn and high-speed, head-on collisions that are common at four-way and two-way intersections. As vehicles approach roundabouts, motorists must reduce their speed so that serious and minor accidents occur less frequently.
For pedestrians, sidewalks along the perimeter of the roadway and shorter crossing distances also increase safety.
Because there are fewer traffic delays, motorists spend less time idling at roundabouts, so fuel consumption, air pollution and noise pollution from vehicles starting and stopping can all be reduced. Vehicle emissions such as carbon monoxide and nitrous oxide emissions can be significantly minimized, thanks to smoother traffic flow through roundabouts and air quality in Indianapolis will improve. Eliminating traffic signals also reduces energy consumption by the City.
The following organizations offer more information on the benefits of roundabouts:
U.S. Federal Highway Administration
Insurance Institute for Highway Safety - Website
Insurance Institute for Highway Safety - YouTube Video
German Church 42nd&46th
Spring MillRoad/91st Street
Five Points/Thompson Road
Final Report-Spring Mill Rd 91st St.pdf