Washington ? First, the elderly woman tried to drive between a delivery van and two people walking on a narrow Florida street. Then, busy chatting, she didn’t notice a car stopping in front of her. At a stop sign, she pulled out in front of a truck.

This was a test to see if it was time for the 75-year-old to give up her keys — and when driving specialist Susan Pierce emerged from the car, it was to break bad news.

“She stood up and literally pounded her fist on the table and said, ‘I am not giving up my driver’s license and not giving up my home,”‘ before storming out, said Pierce, an occupational therapist certified to assess driving skills. “That’s probably the toughest part of my job, when I know I have to say ‘no.”‘

Losing the ability to drive can be a traumatic experience of aging — and knowing when it’s time to quit can be immensely difficult. Tests in doctors’ offices aren’t completely reliable. And nationwide there are only 300 specialists like Pierce certified to perform road tests and offer techniques to help some seniors stay behind the wheel a few more years.

Now medical and traffic groups are beginning some major programs to address the issue:

l The American Medical Assn. will issue guidelines in July to help doctors tell when older patients’ driving is questionable and get them help to stay on the road as long as it is safe. This fall, the AMA also will run a program to train doctors about medical fitness to drive.

l The government recently earmarked $1.6 million to start a National Older Drivers Research Center. Run by the University of Florida and the American Occupational Therapy Assn., it will train more “certified driving rehabilitation specialists” like Pierce, and create better off-road tests to screen drivers for problems.

As the baby boomers age, one in four drivers is expected to be over age 65 by 2030. Some 600,000 people age 70 or older give up their keys each year, the National Institute on Aging estimates.

The AMA guide will urge doctors to ask patients and their relatives about driving problems, watch for possible red flags and hunt medical treatments to help them drive as long as possible.

Occupational therapists increasingly are assessing driving skills with memory and other tests, and offering rehabilitation services to strengthen driving skills.

But ultimately, driving tests are the best tool, said Dennis McCarthy, co-director of the new National Older Drivers Research Center.

The cost for driving evaluations varies from $250 to $800.