1. Babbage
Science and technology
Elderly drivers
Difference Engine: End of the road
Oct 29th 2012, 7:25 by N.V. | LOS ANGELES
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Don't tell me I can't drive
A JOKE courtesy of “Car Talk”, National Public Radio’s
hilarious motoring-advice and agony-aunt show... Two little
old ladies are driving down the road. The passenger
becomes alarmed when she senses her friend behind the
wheel has just run through a red light. But not entirely sure,
she hesitates to mention it. At the next intersection, the
driver definitely goes through on red without slowing. After
the third such instance, the now petrified passenger turns to

2. her friend and says: “Mildred, you just ran three red lights!”
“Heck,” exclaims an aghast Mildred. “Am I driving?”
The way a person’s cognitive ability deteriorates with age is
no laughing matter. Back in 1995, the National Highway
Traffic Safety Administration found that, though motorists
aged 70 and older accounted for only 9% of the American
population, they were responsible for 14% of all traffic
fatalities—and 17% of pedestrian deaths. Since then, the
number of old-folk behind the wheel has risen as baby
boomers edge closer to becoming septuagenarians.
That is rather worrying. It could even reverse (or, at least,
slow) the long-term trend towards safer motoring. The
overall death rate among motorists in America has fallen
steadily since 1975 (from 15 per 100,000 licensed drivers to
12 per 100,000) as a result of seat-belt laws, the crackdown
on drunken driving, better infrastructure and safer vehicles
all round. In contrast, the death rate among 16-year-old
drivers has nearly doubled (from 19 to 35 per 100,000) over
the same period. The main reasons are thought to be the
heavier traffic, moving at higher speeds, and the way
inexperienced teenagers have access to far more powerful
vehicles than their parents had.
Fortunately, teenagers mature, gain experience and put
their risky behaviour behind them. Not so the elderly, who
may not realise how much skill, judgment and reaction time
they have lost, along with their deteriorating vision and
physical strength.
With age, the brain begins to shrink, causing some of its
nerve cells to lose their connections with others. At the same
time, the blood flow in the brain slows down. These changes
are believed to lie behind the deterioration in cognitive
function—the ability to process thoughts—in elderly people.
After retirement, two out of three people suffer from some

3. form of cognitive impairment. It starts with “senior
moments”—the inability to recall the name of an
acquaintance, a word on the tip of the tongue, or where the
keys were put. Most compensate by making notes and
relying more on calendars.
As the years roll by, such memory lapses become more
frequent, and the tendency to misplace things increases.
Those with mild cognitive impairment usually retain their
capacity to learn, read, speak and write, but their attention
span deteriorates along with their short-term memory. This
can lead, eventually, to Alzheimer’s disease or other causes
of dementia.
Cognitive skills are, of course, crucial for driving. So, too, is
co-ordination between eyes and feet as well as eyes and
hands. It is what allows the driver to steer smoothly, gauge
braking distances and slot into fast-moving traffic safely.
Other motor skills are necessary for depressing the pedals in
the correct order, operating hand controls and turning the
head to check blind spots. Most important of all is reaction
time—especially the time needed to take the foot off the
accelerator pedal and hit the brakes, or to jerk the steering
wheel to avoid a sudden obstacle.
In a young person, reaction times can vary from 0.7 second
for something expected to 1.5 seconds for a total surprise.
In the latter case, extra time is needed for the brain to work
out what is going on, and then to decide on a response.
Though reaction times increase with age, older motorists’
greater experience and tendency to drive more slowly help
compensate for the decline in motor skills.
There are no clear-cut guidelines to say when motorists
should surrender their car keys. It depends so much on the
individual. That said, there are some general statistics that
offer assistance. For instance, drivers in their 60s are among
the safest on the road—with no more fatal accidents, on

4. average, than motorists half their age. But once they enter
their 70s, their statistical chance of being killed in a car
crash rises steadily.
Apart from deteriorating cognitive and motor skills, older
drivers become more frail and vulnerable, which increases
their likelihood of breaking bones, damaging organs and
dying as a result of a crash. From their 80s onward, they
start having an increasing number of more serious
accidents. The Insurance Institute for Highway Safety, an
industry research organisation based in Virginia that studies
road accidents, reckons that octogenarians and up have
higher collision rates than any other age group except
teenagers. The fatality rate for drivers who are 85 and older
is nine times greater than for those under 70.
Three factors contribute to age-related motoring accidents.
The first is poor judgment in making turns across oncoming
traffic. The second is drifting out of lane. The third is an
inability to cope effectively with unexpected events. By and
large, septuagenarians involved in crashes at intersections—
where half tend to occur—often misjudged whether it was
safe to cross or turn; octogenarians usually failed to see the
vehicle they hit.
On average, then, motorists approaching their 80th year
should think seriously about giving up driving. The very least
they should do is discuss the matter with their family doctor,
especially if they are taking drugs for chronic conditions (as
is often the case with elderly people). Even over-the-counter
medicines can have active ingredients—such as the
antihistamines in allergy pills, or codeine in cold remedies
and pain relievers—that dull motor skills and distort reaction
times.
But doctors are often reluctant to tell patients to quit driving
altogether—as much out of fear of alienating them, as out of
concern for condemning them to a life of restricted mobility

5. and loss of independence. Given the general lack of public
transport in most parts of America, not being able to go
shopping, meet friends, dine out, see a film or, indeed, visit
the doctor can be a real hardship. Such activities are often
the only things keeping the elderly active and alert.
In California, anyone over 70 who is renewing a driving
licence is required to attend a local Department of Motor
Vehicles (DMV) office every five years for both a written and
a vision test. Also, doctors in California are obliged to report
anyone with worrisome driving abilities to the DMV. A recent
study in Canada, where similar reporting requirements exist,
found that warning the licensing authority of an elderly
patient’s fitness to drive resulted in a 45% drop in crashes
serious enough to warrant hospital treatment.
But how do doctors identify unsafe drivers? The American
Medical Association recommends a few simple tests. One is
to ask a patient to walk ten feet (three metres) down a
hallway, turn round and walk back. If this takes longer than
nine seconds, the patient probably has a driving problem.
Another test, which measures spatial processing and
memory, requires a patient to connect a sequence of letters
and numbers (A to 1, B to 2, C to 3, etc) scattered randomly
on a piece of paper. A patient who does poorly is thought
likely to cause an accident.
Unfortunately, such indirect screening procedures have had
mixed results. In an ideal world, motorists over 70 would be
tested directly for cognitive ability. One method that has
gained favour abroad is the DriveABLE Cognitive Assessment
Tool, which came out of research on fitness to drive at the
University of Alberta. The test is administered by trained
operatives and measures 22 variables while performing six
specific tasks relevant to driving ability. The assessment is
said to determine whether a driver is cognitively impaired
with an accuracy of 93%.

6. Getting the elderly to take a test like the DriveABLE
procedure in order to have their driving licences renewed is
not going to happen—at least, not in the immediate future.
State governments are too strapped for cash as it is. Adding
a 40-minute procedure, conducted by specially trained staff
using dedicated terminals, would make the whole licence-
renewal process prohibitively expensive. But if, alternatively,
taking the test led to the possibility of a lower car-insurance
premium, your aging correspondent would be one of the first
in line.