TRAVERSE CITY, Michigan - Americans are keeping their cars and trucks longer and, even with new car sales increasing, the average age will continue to rise.The average age of the 247-million cars and trucks on US roads hit a record 11.4 years in January 2013, the latest figures available from state registration data gathered by the research firm Polk. That’s up from 11.2 in 2012 and nearly two years older than back in 2007, before the start of the Great Recession.Polk's Mark Seng said: "People are keeping their cars because theirquality is so much better; they're trying to avoid monthly payments. The annual percentage of cars and trucks sent to a scrapyard has dropped by half since the recession.“Cars are just lasting longer."'BIG OPPORTUNITY'The company doesn’t see the age dropping for at least five years, even though US vehicle sales are running at an annual rate of around 15.5-million - near pre-recession levels - and it predicts that the percentage of cars 12 years or older will rise in the next five years.The change creates a big opportunity for repair shops and auto-parts stores.Seng added: “Customers from independent and chain repair shops should be paying close attention to their business plans and making concerted efforts to retain business among the do-it-for-me audience. Retailers have a unique and growing opportunity with potential consumers working on their own vehicles."US sales have risen gradually from a 30-year low of 10.4-million in 2009 because of low interest rates, appealing new models and pent-up demand as people replace aging vehicles kept through the recession. The sales rebound prompted Polk to raise its estimate of the total number of vehicles on US roads by five percent to more than 260-million in five years.'THAT'S NOT GOING TO HAPPEN'But Seng said many people would keep their older car running longer; he can’t remember another time that the average age had grown as quickly.The increase in average age will slow in the coming years but won’t start falling until new-car sales rise and stay high for several years. Older vehicles would have to be scrapped at a higher rate, as well, he said.“With the quality of the vehicles, that’s not going to happen."More people also are financing cars for 72 months, meaning they’ll keep their cars for at least six years, probably longer, Seng said.