If I don't wear a seat belt and am hurt in an accident, it does not affect anyone else. If I choose not to be belted up, am I not merely exercising a personal right?

Seat belt use is more than just a personal right. From time to time we have rear seat passengers dying or getting seriously injured because they had not used their seat belts. This is a cause for concern. Motorists should cultivate the good habit of belting up in the interest of safe motoring. We must also realize that for every unnecessary injury or fatality resulting from a collision, there are economic costs to society. This include medical costs and subsidies as well as the loss of contribution to the economy by the economically active. Besides, an unbelted person might cause injury to belted passengers in the same car by knocking into them.

Retrieved from SPF website, 30/03/07
http://driving-in-singapore.spf.gov.sg/services/Driving_in_Singapore/Faq/seatbeltfaq.htm#personal