Ancient bridges are crumbling nationwide, but Colorado is one state that is managing to keep its bridges in good shape.

Transportation for America - a national coalition of officials from the public and private sectors - recently issued a report ranking the states and Washington, D.C., by the percentage of deficient bridges in their borders. Colorado came in 41st out of 51.

According to the report by Transportation For America, of the state's 8,578 bridges, 566, or 6.6 percent, are considered deficient. That's well below the national average of 11 percent.

Pennsylvania was No. 1 on the "worst" list, with 24.5 percent of its bridges considered deficient.

Much of the reason for Colorado's good showing is due to the state's focus on bridge repair through a program called FASTER, or Funding Advancement for Surface Transportation and Economic Recovery.

The program was established in 2009 by the Colorado Legislature and provides about $100 million a year for bridge repair and replacement.

That special source of funds keeps the state "very proactive when it comes to repairing bridges," said Craig Casper, transportation director for the Pikes Peak Area Council of Governments.

"As a state and locally, we do a really good job if you look around the country," Casper said.

In July, the Colorado Department of Transportation started on millions of dollars worth of bridge work in El Paso County as part of a larger project to fix five miles of Interstate 25 between the Midway Interchange and the Ray Nixon Power Plant.

Deck repairs were started on the northbound and southbound bridges at Little Fountain Creek, Rock Creek, a couple of dry channels and at County Road 415.

In all, the transportation department says, the state replaced 53 bridges though the end of July through the program. Another 22 are being built and 33 are in the design phase.

Since 2011, the report states that the number of deficient bridges in Colorado fell by 18, or 3.1 percent.

"Last year, we replaced five bridges on northbound I-25, all in southern El Paso County," said Bob Wilson, spokesman for the transportation department.

One, a bridge on U.S. 24 over Black Squirrel Creek west of Peyton, was completed in August 2012, according to a list on the transportation department's website. That project cost $3.5 million.

The region of the state with the highest need of repair is the rural, southeastern area, he said.

""A lot of these lesser used roadways have timber bridges," Wilson said.

In addition to the problems caused by their ages - some bridges in El Paso County were built in the 1930s - rainfall in summer and the use of salt and sand in the winter damages the area's bridges, Casper said.

The state's funding may be its saving grace. According to Transportation For American, federal funds are shrinking.

"The money is getting harder to come by," said James Corless, director of the organization.

The chief source, a federal gas tax of 18 cents per gallon, hasn't been raised since 1993, he said.

Meantime, driving has fallen and cars have become more fuel-efficient.

"That has conspired to put less money in the federal transportation fund," he said.