In this Oct. 7, 2014, photo, cracked pylons support a wooden bridge that is closed to traffic because of structural problems south of Mead, Neb. (Nati Harnik/AP)

Another indication that America continues to fall apart came Wednesday with a report that the roadway system is riddled with 61,000 decrepit bridges.

These aren’t bridges on the verge of collapse — though some may be close — but they could become dangerous in time if their deterioration isn’t addressed. Continued delay, however, in tackling rusting or corroding support structures will only increase the problem and expense when they are finally addressed.

In the meantime, some distressed bridges may face restrictions that force the rerouting of delivery trucks, driving up costs for companies and consumers.

There is a modicum of good news in the numbers compiled from the U.S. Department of Transportation’s National Bridge Inventory database: 2,000 bridges that made the 2013 list were repaired.

“State and local governments are doing the best they can to address these significant challenges, given limited resources,” said Alison Premo Black, an economist who analyzed the data for the American Road and Transportation Builders Association (ARTBA).

A number of states recently have increased their gas tax or restructured their transportation funding schemes to raise new revenue. But on the eve of the summer construction season, many states are in limbo in the face of the uncertainty on Capitol Hill, where Congress is staggering toward a May 31 deadline to renew states’ federal funding.

The chance that the deadline will be met, as Congress is on a prolonged Easter recess, is judged to range from slim to none. If the House and Senate fail to meet the deadline that is of their own creation, states can expect a short-term extension of funding at current levels but no long-term certainty that would allow them to address multiyear projects.

ARTBA said that almost a dozen states have delayed or canceled projects because of uncertain federal funding, which provides, on average, 52 percent of the money states use for roads and bridges.

Black says states have been robbing Peter to pay Paul, increasing their investment in bridges at the expense of repaving and rebuilding of highways. She said USDOT data shows a backlog of $755 billion in highway work and $115 billion in bridge work.

“Without additional investment from all levels of government, our infrastructure spending will be a zero-sum game,” she said. “Many of the most heavily traveled bridges are nearly 50 years old. Elected officials can’t just sprinkle fairy dust on America’s bridge problem and wish it away. It will take committed investment by legislators at all levels.”

State transportation departments are responsible for inspecting and rating the condition of bridges. They provide the USDOT with a rating that tops out at 9 — “excellent condition” — and declines from there. A rating of 4 or below indicates that a bridge is structurally deficient.

Black’s analysis of that data found that the 250 most heavily used bridges that rated 4 or below were on urban interstate highways, many of them in California. About 87 percent were more than 45 years old.

In eight states, at least 15 percent of the bridges were rated structurally deficient. Led by Rhode Island (23 percent), they also included Pennsylvania (22 percent), Iowa (21 percent), South Dakota (20 percent), Oklahoma (18 percent), Nebraska (17 percent), North Dakota (16 percent) and Maine (15 percent).

In Virginia, according to the USDOT ratings for 2014, 1,120 bridges that carry almost 5.5 million crossings daily were deficient. The state has 13,800 bridges. In Maryland, those ratings show 317 bridges with a daily traffic load of 4.1 million vehicles were deficient. The state has 5,305 bridges.

In the District, 14 bridges that carry 248,000 vehicles daily ranked deficient. There are 253 bridges in the District.

Correction: An earlier version of this report misstated the number of D.C. bridges that ranked deficient.