JOAN LOWYWASHINGTON (AP) â¿¿ Women have passed men on the nation's roads. More women than men now have driver's licenses, a reversal of a longtime gender gap behind the wheel that transportation researchers say is likely to have safety and economic implications. If current trends continue, the gap will only widen. The share of teens and young adults of both sexes with driver's licenses is declining, but the decline is greater for young men, according to a study by the University of Michigan's Transportation Research Institute. The study looked at gender trends in driver's licenses between 1995 and 2010. "The changing gender demographics will have major implications on the extent and nature of vehicle demand, energy consumption, and road safety," predicted Michael Sivak, co-author of the study. Women are more likely than men to purchase smaller, safer and more fuel-efficient cars; to drive less, and to have a lower fatality rate per distance driven, he said. Over the 15 years the study covered, the share of men ages 25 to 29 years old with driver's licenses dropped 10.6 percent. The share of women of the same age with driver's licenses declined by about half that amount, 4.7 percent. Male drivers outnumbered women drivers from the moment the first Ford Model T rolled off the assembly line in 1908, the year the automobile became popular, and through most of the last century. In the 1950s, when only about half of adult women had driver's licenses, jokes about women drivers were a staple of comedians. But the gap gradually closed. By 1995, men with driver's licenses slightly outnumbered women, 89.2 million to 87.4 million. By 2010, 105.7 million women had licenses, compared with 104.3 million men. Likewise, in 1995 men with driver's licenses outnumbered women in every age group except those over 70. By 2010, women outnumbered men among drivers ages 45 and older and between ages 25 and 29 years old. The share of older women who are also on hanging onto their driver's licenses has also increased.