This is a big rise in the current over-50 segment which makes up 32 per cent of drivers, the findings from research firm ConsumerIntelligence.com showed.
The average cost of a motor insurance policy for a 50-plus driver in 2010 is 449.66.
The research, based on insurance information from 612,000 people, showed that the cost of premiums can vary considerably among the niche insurance brands specialising in this age group, ranging from 378 a year as the lowest quote up to 563 as the highest.
A spokesman for ConsumerIntelligence.com said that the 50-plus motor insurance market was currently worth 3.6 billion and that this figure was likely to increase dramatically as the population ages.
Specialist insurance brands which cater especially for older drivers, including Saga, Age Concern and Help the Aged, collectively only provide motor cover for 16 per cent of the 50- plus market, the research showed.