The designer of this roundabout does not understand proper roundabout design. This is an authoritative source: www.fhwa.dot.gov/publications/research/safety/00067/000676.pdf The roundabout diameter looks excessive (or perhaps the cars are too small). This animation of the Arastradero leg of the roundabout lacks a splitter island, which is an essential safety feature...but a diagram elsewhere (www.sccgov.org/sites/rda/plans/PageMill280/Documents/Concept%203_Caltrans%20Roundabout_Bike%20and%20Ped_36x48.pdf) shows a tiny one. It needs to be larger (p.157). The eastbound approach has an offset that is contrary to the design guidelines of the FHWA (p.145). The crosswalks are in the wrong place. They should be away from the outer circumference by at least 25 feet (p.157). One of the purposes of the splitter island is to curve immediately prior to entering the roundabout in order to slow entering traffic. All of the roundabout's entrances lack that proper curve. This and many other design principles appear not to have been understood by the designer of this roundabout.
