According to R L Polk and Co, the number of vehicles scrapped as a percentage of vehicles on the road has declined for the fourth consecutive year. The percentage of total vehicles scrapped in the US in 2004 was only 5.6 percent, the lowest figure since 1993. Passenger car scrappage rate was 4.8 percent in 2004, the lowest number since 1948. Truck scrappage rate fell to 6.0 percent, down from the 7.7 percent reported in 2003.

The median age of passenger cars increased to 8.9 years in 2004, marking an all-time high. Median age for trucks fell to 6.6 years, dropping from the 6.7 reported in 2003, due mainly to a record 9.8 million new truck registrations in 2004.

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

Passenger cars made up 59 percent of total vehicles in operation in 2004, while light trucks accounted for 41 percent. Polk predicts percentage of cars will decrease to 54 percent by 2009, while light trucks will increase to 46 percent.