DETROIT – Rapidly climbing case counts of COVID-19 have led to cities and counties in several states to issue new restrictions on restaurants and bars. READ: Michigan coronavirus cases up to 244,741; Death toll now at 7,929A new study is renewing concerns about the role restaurants and bars may play in helping to spread COVID-19. Researchers from Stanford University studied cell phone data from 10 U.S. cities collected from March to May of this year. They found full-service restaurants were the riskiest place for new infections, about four times riskier than gyms and coffee shops. READ: Top Henry Ford Health doctor worried about Michigan COVID-19 deaths rising in near future