More Europeans will consider giving up at least one of their cars in the next 12 months, according to a survey on mobility trends.

Already, 90 percent of all drivers have changed their driving habits for cost reasons, according to the European Transportation & Mobility Observatory, a study conducted by the Ipsos marketing institute and car rental company Europcar.

Thirty-nine percent of drivers polled would consider giving up one car in the next 12 months. In urban centers, where congestion is worse and public transportation more easily available, the percentage rises to 45 percent.

With cost the key factor, the study notes that environmental concerns, though still important, are "slightly less responsible for changes in attitudes among Europeans."

In urban centers, according to the poll, 70 percent of drivers say they use public transportation whenever possible. That compares with 55 percent across the continent.

Among urban dwellers, 41 percent of those living in cities with more than 1 million inhabitants view car rental as a potential source of savings and almost half would consider giving up one car.

The study concludes that car-sharing schemes in urban centers “seem to have great potential.”

The survey highlighted that there are practical obstacles to making car rental or car sharing more widely successful. “In order to guarantee success, the rental system will need to be practical, should not involve going to a physical agency and rental for short time slots should be an option,” the study said.

The survey says “European drivers are apparently starting to rethink their relationship with car ownership.” Drivers still value the freedom and independence that comes with car ownership, but the percentage of those feeling strongly about this dropped to 58 percent from 62 percent.

Ipsos and Europcar conducted their survey among people who owned at least one car in the UK, France, Germany, Italy, Spain, Belgium and Portugal. Drivers were polled between August 5 and August 23.

A summary of the survey results can be found here.