COLORADO SPRINGS, Colo. — After 89-year-old Amelia Anderson hit the accelerator instead of the brake, trapping a pedestrian between her car and his, she told police she didn't realize what she had done.

The man lost both his legs. Anderson lost her license.

"The poor lady who hit the man was in shock," witness Irma Fisher said of the July accident. "It was kind of hard to say who you felt worse for."

Crashes can be physically and socially devastating for older drivers. It's estimated that by 2030, people older than 65 will make up 25 percent of driving age Americans.

States are experimenting with various education and screening processes for aging drivers, but not much has worked.

The first problem is figuring out what exactly "old" is. Most states start trying to screen drivers sometime in their 60s or 70s, but changes that can affect driving begin at about the age of 55, said William Sanderman, an assistant coordinator for AARP's Colorado drivers education program.

But all bodies and minds age at different rates, so there are safe 80-year-old drivers and 50-year-olds who don't belong on the road, Sanderman said.

The number of crashes per miles traveled starts out high in the teenage years before falling and staying fairly level from ages 30 to 65, according to the nonprofit Insurance Institute for Highway Safety. At 75, there's a significant increase, and from there to 85, the accident rate triples to about 15 fatal crashes per 100 million miles traveled.

People 65 and older make up about 15 percent of the driving population. Although they spend less time on the road, they are involved in about 15 percent of fatal crashes, said Russ Rader, a spokesman for the Insurance Institute for Highway Safety.

Only 9 percent of all crashes involve elderly drivers.

"There's a myth that older drivers are a menace," Rader said. "But it's the younger drivers who kill other people. Older drivers are just more dangerous to themselves."

The fragility of the elderly is a major factor in fatalities, Rader said. Deteriorating vision, hearing, mobility and health contribute to small accidents, but in any crash, older bodies are more susceptible to injury.

Colorado's strategies for keeping older drivers safe have remained about the same for five years. They include forcing residents 61 and older to renew their licenses more often and in person.

About 25 states have some sort of age-based license renewal requirements. Illinois, New Hampshire and Washington, D.C., require road tests for renewal after a certain age.

But tests can't necessarily divine who will crash in the future and who won't.

"Is there a scientific test (to screen drivers)? I don't think there are any effective tests right now," said Susan Ferguson, vice president of research for the Insurance Institute for Highway Safety.

Although she said more research needs to be done, the only advantage of screening is that often drivers who think they won't pass a test don't bother trying to renew their licenses.

Keeping people on the road or taking them off can be traumatic.

People want to hold onto self-sufficiency and fear becoming prisoners in their own homes, AARP's Sanderman said.

"It's been a horrible, horrible thing," Anderson said of the crash and its aftermath. "It's the worst experience I've had in my life. It has absolutely destroyed me."