I actually sat in a round-about (traffic cirlce) design course. Without knowing rules of your particularly state I can tell you that the design is the typical design called for by high design manual. They asked the class what people would do who came across it, I said merge with traffic and then go through as a vehicle and another person said go to the side walk, both are acceptable methods of navigating the intersection. The are also designed to keep vehicles around 20 mph as noted in general so both are relatively safe, plus no stopping and all legal. Do watch for cars entering onto your right-away though. Been cut off plenty of times in the good old rotaries both in cars and on a bike. Oh the joys of New England.