Over 1.2m people are killed in road traffic accidents around the world each year, according to a report.
There are thousands of road accidents each day
Figures from the World Health Organization and the World Bank suggest another 50m people may be left injured by crashes annually.
The report warns that on current trends road traffic accidents could outstrip stroke and HIV as one of the main causes of preventable deaths by 2020.
The findings are published to mark World Health Day on Wednesday.
It is the first time World Health Day has focused on road safety. Officials at the WHO said they want to highlight the growing threat from traffic accidents.
"Too often road safety is treated as a transportation issue, not a public health issue," said Dr Lee Jong-wook, WHO director general.
The report shows that more than 3,000 people are killed in road accidents every day. Most of these are young adults between the ages of 15 and 44.
It warns that without urgent action the death toll could rise by 60% over the next 16 years.
THE WORLD'S TOP KILLERS
1 Heart disease (12.6%)
2 Stroke (9.6%)
3 Lower respiratory infections (6.6%)
4 HIV/Aids (4.9%)
5 Lung disease (4.8%)
6 Perinatal conditions (4.3%)
7 Diarrhoea (3.1%)
8 Tuberculosis (2.8%)
9 Trachea/lung cancers (2.2%)
10 Malaria (2.1%)
11 Road traffic injuries (2.1%)
12 Diabetes (1.7%)
Source: WHO 2002
It says road traffic injuries could be one of the biggest causes of preventable deaths by 2020 - third only to heart disease and depression.
The report suggests the safest roads are in Western Europe, with an average of 11 road deaths per 100,000 people.
This compares to Africa and countries in the Eastern Mediterranean averaging 28.3 and 26.3 per 100,000 people respectively.
UK Prime Minister Tony Blair and US President George Bush have voiced their support for the campaign to improve road safety.
"Road traffic injuries hit the most deprived communities the hardest," Mr Blair said.
"In the UK, the poorest children are five times more likely to die on our roads than the better off and this picture is replicated around the globe," he said.
FIRST RECORDED DEATH
Bridget Driscoll was the first person to be killed by a car. The 44-year-old mother of two was knocked down at London's Crystal Palace on 17 August 1896. The car was
travelling at 12km per hour. Bridget never knew what hit her. The British coroner recorded a verdict of accidental death. Speaking at the inquest, he warned: "This must never happen again."
"By 2020 road injuries could overtake HIV and tuberculosis to rank third in the causes of premature death and disability around the world."
US President George Bush said: "Today the death toll from traffic injuries is highest in developing countries and it continues to grow as nations become more prosperous and motorised.
"In the United States, traffic accidents remain the leading cause of death for Americans under the age of 35."
Dr Lee urged governments to take action.
"Current figures are alarming enough. Even more alarming are trends," he said.
"If they continue, by 2020, the numbers of people killed and disabled every day on the world's roads will have grown by more than 60%, making road traffic injuries a leading contributor to the global burden of disease and injury."
The WHO-World Bank joint report sets out specific measures aimed at reducing deaths from road traffic accidents.
These include providing affordable public transportation and safe crossings and paths for pedestrians.
It also suggests that communities should be planned so that residents do not have to travel far to go to work, school or local shops.
In addition, it says more could be done to separate different road users, like lorry drivers or those doing the school run.