Primary safety belt laws are recommended based on strong evidence of their superior effectiveness over secondary enforcement laws in reducing motor vehicle-related injuries and deaths. Primary safety belt laws allow police to stop motorists solely for being unbelted, whereas secondary safety belt laws permit police to ticket unbelted motorists only if they are stopped for other reasons such as speeding.
Community Preventive Services Task Force. Recommendations to reduce injuries to motor vehicle occupants: increasing child safety seat use, increasing safety belt use, and reducing alcohol-impaired driving. Am J Prev Med [Internet]. 2001 Nov [cited 2013 Mar 21];21(4S):16?22. Available from http://www.thecommunityguide.org/mvoi/mvoi-AJPM-recs.pdf