Abstract
On July 1 2000, the State of Florida exempted adult motorcyclist and moped riders from wearing helmets provided they have medical insurance of $10 000. Monthly time series of motorcycle occupant deaths are examined from 1/1994 to 12/2001. The interrupted time series analysis estimates a 48.6% increase in motorcycle occupant deaths the year after the law change. The impact estimate reduces to 38.2% and 21.3% when trends in travel miles and motorcycle registrations are controlled. Our findings suggest that the law's age exemption should be revoked. (Author/publisher)