Approaching a roundabout, motor vehicles will already be in two lanes and should already be in the appropriate lane choice based on their next decision (ie turn into a driveway downstream of the roundabout). There should be no lane changes made within the roundabout. When a bus is not present, drivers will yield to vehicles turning within the roundabout’s circulatory lane (making a left turn or u-turn). When an acceptable gap is present, drivers will enter the roundabout a proceed to travel through or use the circulatory lane.
Buses will enter the roundabout from a dedicated travel lane or bus only lane. When a bus is present, vehicles travelling the same direction of the bus are required to yield to the bus entering. This is similar to vehicles having to yield to a bus re-entering the travel lane from a transit stop and is required by law ORS 811.167.
Once the bus has entered the roundabout, drivers are allowed to proceed to yield to other vehicles circulating the roundabout or enter the roundabout when an acceptable gap is present. The buses will diverge back into the busway or bus only lane downstream of the roundabout.