First, slow down! You should approach a modern roundabout at no more than 25 mph. Most importantly, do not merge. Always yield to traffic in circulation when entering a modern roundabout. Do not attempt to cut in front of traffic, but wait for a safe gap. The drivers already in the roundabout have the right of way.
In most situations, a modern roundabout can handle higher traffic volumes with less delay than traffic signals because motorists do not stop for traffic lights. A two-lane roundabout will handle the same capacity as other major intersections in the Valley, and a three-lane roundabout handles up to 6,000 vehicles per hour.