As a Californian court sentences an elderly motorist for the manslaughter of 10 people killed when his car ploughed through a farmers' market, Patrick Jackson of BBC News looks at moves worldwide towards compulsory medical tests for older drivers.
The Japanese government provides refresher courses for ageing drivers
It was one of the most dramatic road accidents of recent times, with 73 people also injured in the 275m (300-yard) swathe George Weller cut across the market in Santa Monica at a speed of 96km/h (60mph).
Weller panicked, his lawyers said, after confusing the accelerator with the brake.
The fact that he was 86 at the time of the accident suggests his age was a factor.
Any driver can panic or make a lethal mistake but demographic trends in the developed world are lending a new gravity to the issue of elderly drivers at the wheel - and most notably in Japan.
With the world's most rapidly ageing population, the number of drivers aged 65 or older there who were the primary party in fatal accidents increased last year to three times the 1989 level.
JAPAN'S SILVER-HAIRED DRIVERS
More drivers in 70-79 age group killed in Jan-Aug 2006 than in 16-24 group
Number of 65-plus drivers in 2005 who were primary party in fatal accidents was three times higher than in 1989
More than 40% of fatalities in 2005 were aged 65-plus
Source: Japanese National Police Agency
And police statistics show that in the first eight months of 2006, 200 vehicle-drivers aged between 70 and 79 were killed in accidents compared to 189 drivers aged between 16 and 24.
"Devising stronger measures to prevent traffic accidents among the elderly is an urgent issue," the Japanese government's 2006 White Paper on traffic safety says.
Dementia is a big concern as it can cause traffic accidents because, for example, sufferers may fail to understand traffic lights or road signs.
Japanese police would like to have a system that could easily test cognitive ability in elderly people instead of relying on a declaration by the driver.
The country expects its elderly population to increase still further and it already runs road safety educational programmes for drivers aged 70 or over.
"The goal is to have elderly drivers become aware of the changes that are occurring in their physical functioning and to offer advice and guidance," the government says.
Lifeline on wheels
Four years ago this month, France was shocked by the deaths of five firemen.
They were attending a minor accident on a motorway near Valence when they were cut down by a car travelling at above 150km/h on a section with a speed limit of 90km/h.
The man at the wheel was 81 and the carnage led to calls for elderly drivers to undergo compulsory medical tests.
Lengthy studies were conducted but nothing was done.
"Everyone realised it was impossible to enforce anything reasonable," Christian Gerondeau, president of the French Federation of Automobile Clubs, told the BBC News website.
Other than in the case of drivers in very poor health or with failing eyesight, no clear, rational criteria can be established for distinguishing between someone who is supposed to be able to drive and someone who is not, he said.
Mr Gerondeau added that cars were essential to many old people: "If you deprive old people of their car, you are going to kill them in another way because they will not be able to move about, they will see almost no-one during the week, they will lose the will to keep living."
According to the French federation's president, the driving habits of the old tend toward road safety: they usually only travel short distances, they take greater care and they drive slowly.
Elderly drivers effectively regulate themselves, according to Ruth Bridger of the UK's Automobile Association Motoring Trust.
"It may be that they stop driving at night, they avoid unfamiliar routes, they stop driving on motorways," she told the BBC.
Recent AA research found that older motorists were "in general, competent and responsible in monitoring and, if necessary, restricting their driving".
Calls in the UK for compulsory testing or even age limits on drivers largely belong to the tabloid press, Ms Bridger said, adding: "You never hear calls to curb younger drivers whenever one wipes out four or five people though that happens almost on a weekly basis these days."
She pointed out that, in 2005, drivers in the UK aged 24 or younger were five times more likely to be involved in road accidents than drivers over 70.
For now, the UK and France remain "younger" countries than Japan, with a median age of about 39 to the Asian nation's 43.
However, the time may come in these countries too when a lifetime of careful driving does not generally guarantee a driving licence for life.