Roundabouts are a very safe and efficient means for intersection control.
Roundabouts with a single-lane approach are used widely and successfully in
Europe and they can easily accommodate peak flows of 2,500 vehicles per hour without significant delays.
Roundabouts with two approach lanes are widely used
in England but are being introduced more cautiously in continental Europe because of concerns about driver confusion and safety. Safety studies completed in
most of these countries indicate that significant safety gains were achieved by
implementing roundabouts in place of conventional intersections. (It should be
noted that the studies conducted in continental Europe predominantly relate to
single-lane roundabouts, not necessarily to roundabouts in general.) Although
roundabouts have been introduced in a few areas in the United States, this modern
tool is still underutilized. State and local agencies should consider the
implementation and use of roundabouts as an alternative to conventional
intersection designs as well as a means for improving traffic safety. When
roundabouts are introduced for the first time in a community, they should be
placed in areas where single-lane approaches would accommodate the existing
traffic. This approach will ensure the successful and smooth operation of the site
and, thus, promote the use of this alternative design.