WASHINGTON (AFP) - Women are more likely to sustain injuries in an auto accident because safety features are designed more with men in mind, a study said Thursday.

Combing through a decade of data about US motor vehicle accidents, three researchers found the odds of serious injury for female drivers wearing seat belts were 47 percent higher than those of men in a comparable mishap.

Previous studies have focused on differences in the way men and women drive, but the researchers -- writing in the American Journal of Public Health -- said another explanation could be the design of safety features.

The positioning of head restraints, for instance, fails to take into account how women's necks are different in size and strength.

Women also face a higher risk of injuries to the lower extremities because of their shorter stature, added Dipan Bose and Jeff Crandall of the University of Virginia and Maria Segui-Gomez of Navarra University in Spain.

To address such sex-specific disparity, "health policies and vehicle regulations must focus on effective safety designs specifically tailor toward the female population for equity in injury reduction," the researchers said.

In another article in the same journal, researchers said that while teenagers drive better the older they get, their likelihood for risky driving

-- like fast starts, hard stops and sharp turns -- remains unchanged.

A US-Canadian team led by Bruce Simons-Morton at the National Institute of Child Health and Human Development outside Washington affixed G-force monitors into the cars of volunteer families in two mid-sized Virginia cities.

Crash and near-crash rates fell among newly-licensed teenagers during three-month research periods, but their level of risky driving behavior remained five times higher throughout.

"It's not clear if this is due to intent, that (risky driving) is fun or if teenagers are simply clueless about the risk of such driving," Simons-Morton said in a conference call with reporters.

One possibility, he said, is that experience gives teenagers a false sense that they could assume more risk. In the United States, driver's licenses can be obtained as early as the age of 16.