How roundabouts work

Slow down.
Watch for and obey traffic signs and pavement markings.
Move into the correct lane as you approach the roundabout.
Yield to pedestrians and bicyclists as you enter and exit the roundabout.
Yield to all lanes of traffic on your left before entering.
Keep your speed low and stay in your lane within the roundabout (do not change lanes within the roundabout).
Exit carefully to your destination. Use your right-turn signal, to indicate your intention to exit.

All motorists, including trucks and other large vehicles, approaching a roundabout must yield to any traffic already within a roundabout.
2015 Wisconsin Act 139 requires drivers of smaller vehicles (such as sedans, pickup trucks, or motorcycles) approaching a roundabout, alongside or adjacent to a larger vehicle (such as tractor-trailer, bus, fire truck, or farm equipment), to provide space by yielding or slowing down, allowing the larger vehicles first entrance and space through the roundabout.
The law was passed in the interest of safety, as commercial trucks can weigh up to 80,000 pounds, and most larger vehicles have an expanded turning radius.

If you are riding on the shoulder or bike lane, merge into the traffic lane before the shoulder ends.
Signal your intent to move into traffic.
Once inside the roundabout, ride close to the middle of the lane to prevent vehicles from passing and cutting you off.
Watch for vehicles waiting to enter the roundabout, as they may not see you.
If sidewalk or a path is adjacent to the roundabout, and you do not want to ride your bike in the roundabout, use the sidewalk or path and proceed as a pedestrian.