Exactly. Not all roundabouts have solid lines. Dotted lines allow cars entering to turn into the roundabouts and to decide which lane they need to be in to continue around the roundabout. "Residents" need to switch lanes sometimes to enter the "resident" gate lane so they cross over from left to right. ALWAYS presume that the car already in the roundabout to your left IS going to cut to the right as a "resident" and you will avoid t-boning them. This IS an over 55 community with public roads, you would think people would expect slower speeds in the roundabouts (its 20 mph in the roundabouts and 35 on mainroads like Morse and Buena Vista) . There is definite confusion as to which cars follow the dotted lines. Most roundabouts show arrows as to which lane to "hold" but not all. Just presume they are going to shift right. Leave the space.