OFFICIAL ROUNDABOUT RULES, WITH LINK:
Choose your lane:
Approaching a two lane roundabout, make a lane choice according to the following rules:
• If you intend to exit the roundabout more than halfway around, use the LEFT-HAND lane.
• If you intend to exit the roundabout less than halfway around, use the RIGHT-HAND lane.
• If you intend to continue straight through, use either lane unless signs or markings indicate otherwise.
http://www.districtgov.org/community...t-02-08-12.pdf