Adapt or, what? Most drivers say they couldn't imagine life without their car
The rapid growth in the use of cars over the last century appears to have halted, although the UK remains "car-reliant", the RAC Foundation says.
While the number of cars being bought continues to grow, and is widening to new groups, the number and length of car trips fell in the decade to 2006.
Car ownership went up by 30% to 29.6m, while the UK population rose by 4%.
The RAC Foundation said the car was here to stay but there needed to be a focus on changing the types being used.
In the past 20 years a consistently high number of people, 80-90%, have said they would find it very difficult to adapt to not having a car, said the report.
The RAC Foundation commissioned the study - The Car in British Society - to look at the changing nature in car ownership, and an independent research team from Oxford and UCL universities carried out the work.
They used data obtained through the government's National Travel Survey, which since 2002 has involved between 8,000 and 9,000 households.
Information was also obtained through focus groups and other research, and statistics gathered from the wide-ranging annual Transport Statistics Great Britain report, compiled at the Department for Transport.
The RAC study concluded that car use was still "embedded" in most aspects of daily life, and that people believed the benefits of having a car still outweighed the disadvantages.
The report said indications showed the declining level of car usage per person was partly due to land-use changes and road development.
Also, car ownership was now open to a wider group - such as older people and the less well-off - who typically used their cars less, it added.
The report also said a decrease in weekly mileage in the decade to 2006 may have been due to more people travelling abroad, increased congestion putting people off, and better public transport in some urban areas.
The RAC Foundation urged the government to "recognise how crucial the car is to all sectors of society" in Wednesday's Budget.
It said in order to avoid hitting the poor hardest, policies to reduce carbon emissions should focus on charging for usage rather than taxing car ownership.
It said national road pricing could achieve that aim, but would be accepted by drivers only if road tax and fuel duty were abolished, and more was spent on road networks.
The report also found:
• In 1989 each car was used for an average of 30 trips per week, which declined to 24 by 2006. The distance travelled by car per week dropped slightly
• Car-licence holding among adults is the highest in rural areas, with 85% of households having one - a link to the availability of public transport
• Nearly half - 46% - of households have a relatively low annual mileage of 1-5,000 miles, while 10% travel more than 15,000 miles per year.
The report's lead researcher, Dr Karen Lucas from Oxford University, said: "Our research suggests that most people cannot envisage a future without their cars and many would go to considerable lengths to continue using them.
"The current policy debates about reducing car use, through road pricing and personal car allowances, do not fully consider the impact that this might have on people's lives, especially for those on low incomes or with limited options for alternative modes of travel."
RAC Foundation director Stephen Glaister said British people were "not addicted to driving", but were "car-reliant".
"The car... is the bedrock of our society and our economy... there is no question of getting rid of cars.
"Instead we must change the type of cars we use - smaller, lighter, more fuel-efficient models with fewer cradle-to-grave CO2 emissions."