Data from the 1977 National Personal Transportation Survey and from the Fatal Accident Reporting System were used to compute mileage-based fatal crash involvement rates of drivers, by age, sex, and time of day. Teenagers drive less than older drivers but do more of their driving at night. They have much higher numbers of drivers in fatal crashes based on miles driven than do older drivers; their nighttime rates are particularly high. Sixteen year olds, especially males, have by far the highest fatal crash rates per mile, both nighttime and daytime. More widespread adoption of driving curfew laws would very likely produce substantial reductions in fatalities involving 16 yr old drivers.