The number of fatal and serious accidents on Kent's roads has fallen by more than half over the past ten years, according to the latest figures.
Kent County Council said 553 people were killed or badly injured in 2010 compared to 1,196 a decade earlier.
The authority said the figure was at an all-time low and it had beaten the government's target of a 40% reduction.
Councillor Bryan Sweetland said more could be done to reduce the number of casualties further.
The provisional crash data shows that 55 people were killed and 498 people were seriously injured last year.
Mr Sweetland added: "Each of these casualties is a tragedy for the victims and their families. In many cases they could be avoided.
"Motorists have got to be encouraged to take more responsibility for their own actions."
Kevin Clinton, head of road safety at RoSPA, said: "It's great to see that Kent has achieved such a significant reduction in road casualties over the last few years.
"However, it's important that road safety professionals - and the public at large - do not become complacent.
"Road safety is not a problem solved; it's an ongoing issue that continually throws up new challenges.
"With new technology, increasing volumes of traffic on the roads, and new ways for drivers to be distracted there is plenty more work to be done."