This paper estimates 1993 U.S. highway crash incidence and costs by driver age, alcohol use, victim age, occupant status, and restraint use. Notable findings are: (1) crash costs of novice drivers are high enough to yield preliminary benefit-cost ratios around 4-8 for a provisional licensing system that restricts driving after midnight and 11 for zero alcohol tolerance for young drivers with violators receiving a 6-month suspension; (2) the costs to people other than the intoxicated driver per mile driven at BACs of 0.08-0.099% exceed the value of driver mobility; (3) the safety costs of drunk driving appear to exceed $5.80 per mile, compared with $2.50 per mile driven at BACs of 0.08-0.099%, and $0.11 per mile driven sober; (4) highway crashes cause an estimated 3.2% of U.S. medical spending, including more than 14% of medical spending for ages 15-24; (5) ignoring crash-involved occupants whose restraint use is unknown, the 13% of occupants who police reported were traveling unrestrained accounted for an estimated 42% of the crash costs; and (6) if these unrestrained occupants buckled up, the medical costs of crashes would decline by an estimated 18% (almost $4 billion annually) and the comprehensive costs by 24%.