Congress has steered $1.1 billion since 2001 to favored projects at airports that cater to private planes, much of it going to low-priority improvements or to benefit corporate jets, a USA TODAY analysis shows.

The projects, known as earmarks and added to annual spending bills by lawmakers, have upgraded airports that are home to jets of major companies. Some earmarks have paid to lengthen runways to attract more corporate jets or larger ones.

About $100 million went to low-priority projects, such as renovating or building terminals at airports that are used mostly by private pilots, according to an analysis of annual transportation spending bills and Federal Aviation Administration ratings of airport projects.

A 2007 report by the Department of Transportation inspector general criticized earmarks, saying that "many low-priority earmarked projects (are) being funded over high-priority projects." A Congressional Research Service report in May said earmarks could cut federal aid to projects aimed at easing flight delays at the nation's 35 busiest airports.

"We are putting politicians' interests ahead of safety and efficiency," said Sen. Tom Coburn, R-Okla., an earmark critic who wants money spent on improving safety and reducing delays.

FAA spokeswoman Marcia Adams said earmarks account for 5% of airport grants and that all approved projects comply with federal standards.

Airport grants are paid from a fund that gets most of its money from airline passengers through taxes on airplane tickets. Private pilots pay taxes on airplane fuel.

USA TODAY reported in September that more than 2,800 airports with no scheduled passenger flights received $15 billion in grants since 1982. Earmarks have benefited some of those airports:

•Statesville Regional in North Carolina got $6.5 million in earmarks between 2003 and 2008 to extend its runway and improve its landing system. The city promised the improvements in 2003 to Lowe's when the $48-billion-a-year home improvement chain decided to base its five jets at the airport and wanted the added capacity, Statesville Planning Director David Currier said. Lowe's political-action committee and executives have given $11,750 since 2005 to Rep. Virginia Foxx, R-N.C., who sponsored earmarks in 2006 and 2008. Company spokeswoman Maureen Rich said the upgrades help other airport users, and noted that Lowe's has a major corporate campus in Foxx's district. Foxx, who has since taken a pledge not to request earmarks, said in a statement that airport funding was the top priority of local officials.

•Lake Cumberland Regional Airport in Kentucky got a $3.5 million earmark from Rep. Hal Rogers, R-Ky., in 2004 to build a passenger terminal when the airport had no passenger flights. Somerset has handled about 80 takeoffs and landings a day of private planes, FAA figures show, until June when Locair began flights to three destinations, including Washington.