Thousands die on the roads each year
Road traffic crashes left one in 100 people in England and Wales bereaved in a 35 year period, a study suggests.
Researchers from the London School of Hygiene and Tropical Medicine examined data on road traffic crash deaths between 1971 and 2005.
Extrapolating from a sub-set of 1.1% of the population, they calculated 590,500 people had been bereaved by a road traffic crash in that time.
The study appears in the journal Injury Prevention.
Fatal vehicle collisions kill more than one million people worldwide every year, with around 3,000 deaths in the UK.
Ten times as many people are left seriously injured or disabled as a result.
The researchers examined data on people born on one of four specific days of the year - amounting to just over 1% of the population.
In that group 1,801 adults and children were killed in road traffic accidents between 1971 and 2005.
The dead left behind a total of 6,467 close relatives, including step relatives and half siblings.
Applying that calculation to the whole population, the researchers concluded that nearly 600,000 people across England and Wales were likely to have been bereaved following a road traffic accident in that 35 year period.
As the population of England and Wales was 53.4m in 2005, that equates to 1.1% of people who had been bereaved in this way.
The overall figure includes more than 131,000 parents who had lost a child and more than 107,000 children who had lost a parent.
The researchers admit that producing precise figures is impossible as there are many factors to take into account.
However, their calculation does underline just what a huge impact road traffic accidents have on society.
They go on to estimate that since 1951 a total of 708,518 people in England and Wales have been bereaved following a road traffic accident.
This is a rough estimate, based on about 68,000 deaths on the road during the 1960s, and 50,000 during the 1950s.
The researchers warn of a huge emotional legacy from such a death toll - and a significant cost to the health service in having to deal with serious mental health problems, such as post traumatic stress disorder and depression.
The economic impact is also considerable: In 2002, the Department of Health estimated preventing all fatal, serious, and minor road traffic casualties in England, Wales, and Scotland would save up to £17.76bn.
Lead researcher Dr Phil Edwards said: "Road traffic accidents are a leading cause of death and disability.
"It is a great shame that society now seems to accept this sort of death toll as normal.
"Some people might think that one in 100 people walking along the street have lost a brother or sister, a mother or father in this way is not a lot.
"But I hope that some people will be alarmed that quite so many people have lost someone close to them."