The government said the reform, which was two years in the making, will reduce costs for motorists and extend a six-month income-replacement safety net to all injured road users – including, for the first time, at-fault drivers.

It will do so by crimping the profits of insurers, cutting fraudulent and exaggerated claims, and by putting a six-month limit on benefits for less-severe motor accident injuries, effectively cutting off support for "soft tissue and minor psychological injuries" after that point. 

Legal experts estimate up to a third of people injured in motor accidents will lose the right to benefits after six months from their accident under the new scheme. 

NSW drivers pay the highest CTP premiums in Australia, at $703 for the average city motorist – an increase of 85 per cent on 10 years ago. The government attributed this to a significant spike in minor injury claims, insurer profits and fraud. 

Ms Berejiklian said "just 45¢ in every Greenslip dollar is returned to injured road users. The rest is chewed up in scheme costs, including insurance company profits and legal fees." 

Under the new scheme, the government said, 60¢ in every dollar will return to injured road users, and provide "Greenslip relief" to every motorist.

However, the Labor opposition was sceptical about how the government would ensure premiums come down. 

Andrew Stone, of the Australian Lawyers Alliance, said the government's initial scheme would have meant some people with severe, lifelong orthopaedic injuries would have been cut off from benefits after five years. 

"What we have now is a much fairer alternative where people with significant orthopaedic injuries, who cannot work as a result of their injuries, will be compensated for a loss of income," he said. 

Mr Stone estimated up to 3000 injured people a year would lose their benefits under the new scheme, while preserving benefits to a further 4000 to 6000.