By Tom Symonds
Transport correspondent, BBC News
The root causes of a bus crash near Alton Towers in 2008 were not probed
Britain needs a road accident investigation body to work alongside rail, air and marine inquiry teams, according to the RAC Foundation.
The research organisation says lessons are not being learned from the deaths on Britain's roads.
It wants road accident investigators to find out why collisions have happened rather than who was to blame.
Around 45 people a year are killed in air, train or marine accidents, but in 2008 more than 2,900 died on the roads.
When there is an air crash, train crash, or tragedy at sea, specialist investigators are called in to find the causes.
Traffic collision investigations are currently the job of the police, but they gather evidence to bring convictions, not to explain events.
The RAC Foundation's report makes no criticism of the police service.
Its author, Dr Chris Elliot, says someone should be taking a wider look at the causes - both direct and contributory.
"In 1972 the groundbreaking Robens report revolutionised workplace safety and led to the creation of a coherent and rational legal structure that has saved hundreds of lives," he said.
"It is time to have a similar root and branch review of the way transport safety policy is implemented and co-ordinated.
"We have to challenge the global trend towards criminalising accidents and their investigation."
A road accident investigation body would not seek to blame but could lead to improvements in policy, road or vehicle design and even traffic management.
Dr Elliot's report highlights an accident on the M6 in October 2008 in which six family members were killed when a truck ran into their stationary car.
Police found the cause to be a lapse of concentration by the truck driver who was charged with causing death by careless driving and sentenced to three years in prison.
An 18-month inquiry followed the 2007 Grayrigg rail crash in Cumbria
Dr Elliot has questioned whether his lapse was the root cause of the accident.
"Motorways are very safe when traffic is flowing smoothly," he said.
But when the traffic flow is disrupted, a single lapse could lead to tragedy, he added.
"It is arguable that the root cause of the accident was an earlier accident on the same section of motorway that caused the traffic jam in which the car was stopped," he said.
"It is not clear whether this could have been cleared more quickly if, for example, there had been no pressure to investigate possible criminal offences."
The report says the level of investigation varies hugely between different types of transport.
The 2007 Grayrigg rail crash in Cumbria, in which one person died, resulted in an 18-month inquiry, a 250-page report, and 29 safety recommendations.
Officer numbers down
But when a bus crashed in August 2008 near Alton Towers in Staffordshire, also killing one person, there was no investigation into the root causes.
That was the case despite locals criticising what they called inadequate roads and sharp corners.
It is possible the police could carry out this type of evidence-gathering and analysis, but the number of traffic police officers has fallen.
The sheer regularity of road deaths means there would be far more work to do than for air, sea or rail crashes.
The government does not support the idea. It believes wider research into road safety is the best way to learn lessons.