Who's the more likely menace -- the 18-year-old riding your bumper on the Beltway or the 85-year-old driver crawling at 40 mph in front of you?
Conventional wisdom says it's the kid. After all, teens have more accidents than anyone else.
But federal reports say the 85-year-old has the higher risk of crashing when he's on the road, even though the elderly generally drive less and have fewer accidents.
The comparison is not just academic. As the Baby Boom generation grays, more and more elderly drivers will be on the road, posing special safety problems that states may have to address.
On the other hand, senior citizens represent a powerful lobby. They turn out to vote, and so far they've managed to ward off special examinations or restrictions in most states.
By the year 2020, people age 65 and older are expected to make up almost 20 percent of the U.S. population, compared with 12 percent in the mid-1980s, according to the National Highway Traffic Safety Administration.
The crash statistics are startling. Sixteen to 19-year-olds have almost 30 crashes per million miles traveled, compared with about 40 crashes for those 85 and older, an NHTSA report says.
Drivers from 35 to 65 years old are the safest, but the accident rate per mile driven begins climbing after 70. After 75, people are twice as likely to be involved in a crash, per mile driven, as younger people.
Two back-to-back tragedies caused by elderly drivers this spring focused national attention on safety issues.
In New York, a 74-year-old woman killed five people and injured 26 others when she lost control of her car and drove into a crowded park. The driver contended she could not stop the car, although there was no evidence of a mechanical problem.
A few weeks later, an 87-year-old man plowed into a group of third-graders in Chicago, killing one child and injuring others. He was charged with a minor traffic offense, a Chicago police spokesman said.
Locally, an 83-year-old Parkville woman lost control of her 1974 Mercedes-Benz last Monday and struck a 14-year-old girl. The car pinned the teen against a wall and crushed her legs, causing serious injuries. Police said charges are pending.
Cases in which elderly drivers kill or maim children make the most headlines, although more often than not, elderly drivers are the ones to lose their lives.
Because of their physical vulnerability, senior citizens are much more likely to be killed in an accident than middle-aged drivers, said Dr. Robin A. Barr of the National Institute on Aging in Bethesda.
While fatalities for drivers of all ages dipped 8 percent during the 1980s, fatalities for drivers 65 and older rose by 43 percent, he said.
Studies show that the physical and mental attributes required for driving decline with age and certain diseases. They include eyesight, hearing, reaction time and the ability to judge complex traffic situations.
However, the rate of decline differs for everyone. One driver may be quite capable at 88; another may have trouble at 68.
Busy highways can be especially confusing to the elderly.
In 1990, for example, an 87-year-old Cape St. Claire woman drove 5 miles the wrong way on U.S. 50. She wasn't hurt, but two minor accidents occurred along the way. Police said advanced age may have affected her judgment.
The elderly are more likely to crash in urban areas during daylight hours and to hit another car, federal statistics show. They have more trouble making turns and merging into traffic than younger drivers.
Those trends could be seen in a 1991 accident on U.S. 50. An Annapolis couple, both 74, died after the husband tried to make a left turn and hit an oncoming pickup truck. Several other people, including a 3-year-old, were injured.
Nonetheless, many states, including Maryland, do not have special licensing procedures to weed out older drivers whose skills have declined.
States often try to err on the side of the elderly, who have a powerful lobby in Washington and state capitals. Maryland law, for one, prohibits the Motor Vehicle Administration from using a driver's age as grounds for re-examination.
Any Marylander may be re-examined if he has a medical problem that affects driving or if he abuses alcohol or drugs, said MVA chief W. Marshall Rickert. The elderly make up a minority of those cases, however, perhaps because their doctors or families don't wish to report them.
Mr. Rickert said he is waiting for the results of studies by a national association of motor vehicle administrators before deciding whether Maryland's licensing system should be changed.
He and others in the field say they're trying to balance safety with elderly peoples' need for transportation and independence.
Older drivers have fought efforts to single them out for re-testing. "We're clearly opposed to age-based testing," said Ted Bobrow, a spokesman for the American Association of Retired Persons, which offers driver safety courses to its members.
"The different studies that are out there don't demonstrate that age is an effective indicator [of ability]. Shouldn't we be making sure all drivers are safe, regardless of age?"he asked.
Politically speaking, it's easier to take aim at the problems of young drivers, such as by raising the drinking age, than to legislate against their grandparents.
"You can always pass laws against younger drivers because they don't have a constituency. You can't pass laws against older drivers because they have a constituency -- and a vocal one," said Sam Yaksich, executive director of the Automobile Association of America's Foundation for Traffic Safety.
Senior citizens also have some statistics on their side. Although both they and teen-agers have the highest crash risks, the elderly have fewer accidents because they spend less time on the road, researchers say. That often translates into lower car insurance rates, too.
In Maryland, people age 65 and older have fewer accidents per licensed driver than other age groups, according to data compiled by The Sun.
However, it was impossible to determine the crash rate per licensed driver for people in their late 70s or early 80s, when problems generally begin, because the state lumps accidents involving people over 70 into one category.
Some groups say states should issue restricted licenses to marginal drivers that allow them to drive during certain times and to certain places only.
But critics say elderly people already restrict themselves when they feel their abilities slipping. They may drive only to the grocery store and doctor's office, taking familiar routes during daylight hours and good weather conditions. Many stop driving at night because of vision problems.
Connie Johnson, a 71-year-old knitting instructor from Severna Park, said she has a friend who limits her driving because of very poor eyesight.
She and other members of her knitting group at the Annapolis Senior Center resent the way people stereotype older drivers. "We all feel our age has nothing to do with the way we drive," Ms. Johnson said.
Oregon has developed an effective, albeit somewhat expensive, program of counseling elderly drivers while respecting their independence, said Peter W. Nunnenkamp, manager of the Oregon Motor Vehicle Division's driver safety section.
Oregon requires doctors to report any patient who loses consciousness or control. A number of elderly people come into the system this way, as well as through reports from family and police.
The motor vehicle agency then decides whether to have that driver meet privately with a counselor. The counselor discusses the person's medication with him, asks a few questions to determine his alertness and tests his reflexes. The counselor may ask the person to drive a few blocks.
If he's not happy with what he sees, the counselor will requir the driver to take an oral or written test, or a driving exam, or both. Most importantly, the counselor will coach the driver on what skills he needs to pass.
This approach reduces stress and treats them fairly," Mr. Nunnenkamp said.