Question: who designed the traffic circle in long beach ca?
Answer: Werner Ruchti, German engineer Werner Ruchti

In 1930, German engineer Werner Ruchti was contracted to design the traffic circle, which was to be based on European models.  Construction was expedited in order to accommodate the increased vehicle traffic that was expected with the 1932 Summer Olympics, held in Los Angeles, as many of the aquatic and rowing events were to be held in Long Beach.