Front & rear seat belt laws vary by state; here's a summary of each state law, though it doesn't mention the taxi exemption. http://www.ghsa.org/html/stateinfo

Front & rear seat belt laws vary by state; here's a summary of each state law, though it doesn't mention the taxi exemption. http://www.ghsa.org/html/stateinfo/laws/seatbelt_laws.html http://www.ghsa.org/html/stateinfo/laws/seatbelt_laws.html