The Irondequoit roundabout is fairly new,most likely dating back to about 5 years ago. Along with new designs of roads comes the physics that are necessary to build the newest features. Probably one of the easiest physics sections to associate with these roundabouts is centripetal acceleration. As we all know centripetal acceleration is pointed inwards towards the center of the circle. for this acceleration to happen there must be a resultant force , this force is called the centripetal force. the centripetal force measured in newtons can be different forces in different settings such as gravity and friction.
take a rubber stopper on a string for example. If you swing the string in a circular pattern the stopper will pull towards the center. once the stopper is released from the string it will fly straight from the facing position. In roundabouts, like the ones in Irondequoit, as a car goes around the circle the centripetal acceleration and force is pulling the car towards the center keeping it from flying off the tracks. Also similar topic involved in race car driving. Thanks to centripetal force and accelleration, cars are less easily flung off the track along with friction keeping them on the track as well.