NEW YORK, Feb 10 (Reuters) – A new index using truck stop fuel purchases to gauge future U.S. economic activity slumped in January but its three-month moving average showed growth, suggesting the economy is still on the road to recovery.

The Ceridian-UCLA Pulse of Commerce Index (PCI) produced by UCLA Anderson School of Management fell 36.8 percent in January from the previous year, after a strong increase in December.

The index’s three month moving average is up 3.3 percent thanks to the big gain in December, suggesting economic recovery is proceeding slowly, according to the survey published on Wednesday.

The PCI is now up 3.6 percent compared to one year ago, marking its first year-on-year increase since April 2008.

The index tracks the volume and location of diesel fuel being purchased around the United States. It anticipates shifts in economic growth as it shows when and where increases and decreases in shipments of raw materials and goods are taking place, said Edward Leamer, the index’s chief economist.

“The interstates that crisscross the country are the arteries of the system, and the product flowing in the trucks are the life blood,” Leamer said. “If you don’t move that product the economy comes to a grinding halt.”

The index is produced in conjunction with Ceridian, a business services company that processes credit card payments.

NEW YORK (Reuters) – The AAA credit rating, once a point of pride for leading industrial companies, has lost its luster as confidence in ratings agencies has fallen and the number of companies in its ranks has dwindled — sometimes by choice.

Some companies, including General Electric Co <GE.N> and Berkshire Hathaway Inc <BRKa.N>, lost the AAA stamp after financial losses hampered their performance.

But other companies, most recently Pfizer Inc <PFE.N>, have sacrificed top ratings for a more aggressive growth stance, often funded by debt.

While companies pay a price for reduced ratings in higher borrowing costs, analysts say the loss of a top-tier rating is not as dire a fate as in the past.

“Having pristine credit quality is not the most important factor for determining whether or not management has been a good steward of a corporation’s well-being anymore,” said Sean Egan, managing director at ratings firm Egan-Jones Group.

The allure of the AAA has been dimmed by the loss of confidence in ratings agencies, which have come under fire for assigning top ratings to risky mortgage securities that later defaulted — moves that exacerbated in the ongoing financial crisis.

The three main agencies, Standard & Poor’s, Moody’s Investors Service and Fitch Ratings, are paid by debt issuers to rate their creditworthiness on a scale that directly impacts the cost of selling debt. The top rating, AAA, was once a cherished grade, reflecting the solid financial position of the issuer.