Today's high gas prices could cut auto deaths by nearly a third as driving decreases, with the effect particularly dramatic among price-sensitive teenage drivers, the authors of a new study say. Professors Michael Morrisey of the University of Alabama and David Grabowski of Harvard Medical School found that for every 10 percent increase in gas prices there was a 2.3 percent decline in auto deaths. For drivers ages 15 to 17 the decline was 6 percent and for ages 18 to 21 it was 3.2 percent. Annual auto deaths in the U.S. typically range from about 38,000 to 40,000 a year.