A new report from the AAA Foundation for Traffic Safety has found that older Americans are extending their time behind the wheel compared to previous generations.

For example, 84 percent of Americans 65 and older held a driver’s license in 2010 compared to barely half in the early 1970s. Today, one in six drivers on U.S. roads is age 65 or older.

This new research shows an increased auto-mobility of older drivers, with travel patterns indicating about a 20-percent increase in trips and a 33-percent increase in miles traveled between 1990 and 2009.

The report, titled “Understanding Older Drivers: An Examination of Medical Conditions, Medication Use and Travel Behaviors,” also reveals that 90 percent of older drivers use prescription medications. Two-thirds take multiple medications.

Previous foundation research has shown that combinations of medications, both prescription and over-the-counter, can result in an impairment in safe driving ability.

“This level of medication use does raise concerns, yet evidence indicates seniors are fairly cautious,” said Peter Kissinger, AAA Foundation president and CEO. “In fact, these findings show that older drivers using medications are more likely to regulate their driving – reducing daily travel, avoiding driving at night or driving fewer days per week.”

The report also reveals gender differences when it comes to medication use behind the wheel. Older women who use medications are more likely to regulate their driving compared to men. Even when they are without a medical condition, female drivers drive less than their male counterparts with a medical condition.

Additional key highlights from the report include:

• 25 percent of men and 18 percent of women remain in the workforce after age 65, resulting in more than double the work-related commutes for drivers 65 and older compared to 20 years ago.

• 68 percent of drivers age 85 or older report driving five or more days per week.

• Three-quarters of drivers age 65 or older with a medical condition report reduced daily driving.

• Self-regulatory behavior, among those taking multiple medications or having a medical condition, declines with increasing income. Female drivers age 65-69 with an annual income under $13,000 were 62 percent more likely to restrict nighttime driving than women with incomes over $70,000.

Knowing that medication use is very high among senior drivers, the AAA Foundation and AAA developed tools such as Roadwise Rx to help seniors and their families understand common side effects of prescription and over-the-counter medications, herbal supplements and foods.

“AAA’s Roadwise Rx is an online tool that generates personalized feedback about how these interactions between prescription and over-the-counter medicines and herbal supplements can impact safety behind the wheel,” said Jake Nelson, AAA’s director of traffic safety advocacy. “Drivers are encouraged to discuss the confidential results with their doctor or pharmacist to learn how to mitigate possible crash risks.”

To access all the free resources AAA offers to senior drivers, you can visit SeniorDriving.AAA.com.

The AAA Foundation study primarily analyzed the most recent data from two national databases – the 2009 National Household Travel Survey (NHTS) and the 2011 National Health and Aging Trends Study (NHATS).