Deaths and serious injuries on the roads are likely to cost society £110 billion in the years to 2030, according to a report commissioned by a parliamentary safety group.
The total of those killed or seriously injured (KSIs) over this period is expected to be around a third of a million, said the report prepared for the Parliamentary Advisory Committee for Transport Safety (Pacts).
These huge figures are expected despite the report predicting a dip in KSIs and slight injuries by 2030 compared with figures for 2012.
Deaths are likely to reduce from a figure of 1,754 in 2012 to around 1,000 a year by 2030, with serious injuries falling from 23,029 in 2012 to about 11,000 in 2030. Slight injuriess are forecast to fall from 170,930 in 2012 to about 150,000 by 2030.
Pacts' executive director David Davies said: "A third of a million people, the equivalent of the population of Reading, will be killed or seriously injured on British roads before 2030 if current trends are allowed to continue. There are proven, cost-effective and affordable ways to make our roads safer.
"Business as usual is not good enough. Ambitious targets and properly resourced interventions are needed. Work should start now on a new national road safety strategy. We can no longer rely on the recession to reduce casualties."
The report was prepared by former Transport Research Laboratory team member Kit Mitchell and Emeritus Professor of Transport Studies at University College London and Pacts director Richard Allsop.
They said: "Road safety is a British success story, but there is still much more that can be done at relatively low cost, to reduce casualties to numbers a good deal lower than those projected in our report."
The full report is to be released at the UK road safety summit in London on Thursday.