The center portion of a mini roundabout is called a truck apron. While cars navigating the turns should remain in their lanes, trucks use this space to accommodate their turning radius.
Remember to always yield to pedestrians in the crosswalk, yield to vehicles on your left, and enter the circulating lane when there is a gap in traffic.
The County Highway Department has a couple of helpful roundabout videos posted on their webpage.
Click here to see the videos