1. Modern roundabouts follow
the “yield-at-entry” rule. Approaching vehicles must wait
for a gap in the circulating flow before entering the
circle. Many traffic circles require circulating vehicles to
grant the right of way to entering vehicles. Some traffic
circles also use stop signs or signals to control vehicle
entry.
2. Modern roundabouts involve
low speeds for entering and circulating traffic. Roundabouts
are generally much smaller than traffic circles, which
naturally causes drivers to reduce speed within the circle,
thus reducing the likelihood of accidents.
3. Modern roundabouts eliminate other problems associated
with traffic circles. In giving priority to entering
vehicles, a traffic circle tends to lock up at higher
volumes. The operation of a traffic circle is further
compromised by the high speed environment in which large
gaps are required for proper merging.