The number of vehicles scrapped as a percentage of vehicles in use has declined for the fourth consecutive year, according to RL Polk & Co.

The percentage of total US vehicles scrapped in 2004 was 5.3%, the lowest scrappage rate since 1993.

For passenger cars in 2004, the scrappage rate was 4.8%, the lowest since 1948, when the rate was 4.1%. In 2004, trucks also displayed a decrease in the rate of scrappage to 6.0%, a notable slip from 7.7% in 2003.

The median age of passenger cars increased to 8.9 years, an all-time high. For trucks, the median age fell to 6.6 years, due mainly to a record 9.8 million new trucks registered in 2004, with 9.3 million of those being light trucks.

"Since vehicles are lasting longer, and new light truck registrations remain around nine million per year, we will see a noticeable change in the proportion of cars versus light trucks in the near future," said Polk spokesman Marty Miller.

Throughout 2004, passenger cars comprised 59% of the vehicles in operation and light trucks accounted for 41%. Polk projects that by 2009, the percentage of cars will decrease to 54%, while light trucks will increase to 46% of vehicles in use.