Traffic circles are the absolute worst. I still don't understand how all these studies show they are safer than a light intersection that is well timed and provides left turn arrows. Every time I enter one, I feel like it's an accident waiting to happen.
They force drivers/bikes to:
-Decide if it is safe to enter while focusing on approaching traffic approaching at a constantly changing angle, oftentimes from more than 1 location. The constantly changing angle, incidentally effectively reduces visibility.
-Calculate their route, as entering a two lane traffic circle often means certain lanes are exit only, and this requires further contemplation before deciding whether or not to enter, as well as figuring out roughly where they are exiting at, since the signs are often too close together to be really useful while trying to steer around the circle and focus on others around you.
-Checking for pedestrians, who can appear rather suddenly as these two things are figured out.
-Checking again for approaching bikes/cars before pulling out.