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.

2015 Wisconsin Act 139 requires drivers at roundabouts to yield right of way to trucks and other large vehicles (and combinations of vehicles, such as trucks towing boats or recreational vehicles (RVs) towing cars) measuring at least 40 feet long or 10 feet wide.
Motorists are required to give space to larger vehicles when approaching and driving through roundabouts.
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.
Drivers are asked to remain mindful that all motorists, including trucks and other large vehicles, approaching a roundabout must yield to any traffic already within a roundabout, as signed and per law.

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.