Large Vehicles / Trucks / Emergency Vehicles
Large vehicles
When car drivers approach a roundabout, do not overtake large vehicles (trucks and buses). Large vehicles may have to swing wide on the approach or within the roundabout. Watch for their turn signals and give them plenty of room, especially since they may obscure other conflicting users.
Driving a truck
To negotiate a roundabout in a truck, you may need to use the full width of the roadway, including mountable aprons if provided. Be mindful of the location of all other users of the roundabouts. Prior to entering the roundabout, you may need to occupy both lanes. Signal your intentions well in advance and satisfy yourself that other users are aware of you and are giving you consideration.
Emergency vehicles
If you are in a roundabout when an emergency vehicle is approaching, proceed to beyond the splitter island of your exit before pulling over. If you haven't entered the roundabout yet, wait until the emergency vehicle has passed before entering. These steps will help to clear out the roundabout for the emergency vehicle.
Adapted from: Federal Highway Administration, Roundabouts: An Informational Guide, Report No. FHWA -RD-00-067, June 2000.