A new report released yesterday says people are keeping their cars and trucks longer as quality improves and the uncertain future of the US economy makes new purchases less appealing.

Automotive consulting firm R.L. Polk says the median age of cars on U.S. roads was 9.2 years in 2007. That ties the previous year's record high.

The median age for trucks and sport utility vehicles rose 4 percent to 7.1 years.

Polk says increasing durability allows owners to keep cars longer.

In 2007, 41.3 percent of all cars were 11 years or older, compared with 40.9 percent the year before.