York County's locally owned bridges are among the most sound in the state.

Of those bridges, 17 percent are structurally deficient bridges. Only four of Pennsylvania's 67 counties have a smaller percentage of structurally deficient bridges.

Statewide, 35 percent of locally owned bridges are structurally deficient.

When bridge safety became a front-and-center safety issue in the wake of the Minnesota bridge collapse four years ago, York County already had a low percentage of locally owned structurally deficient bridges.

In 2007, York County had 32 structurally deficient

bridges -- or about 16 percent. As of June, there are 35 structurally deficient locally owned bridges in the county -- or about 17 percent.

The York County commissioners typically approve about $250,000 a year strictly for bridge maintenance, said Steve Malesker, project manager for the county's bridge maintenance program. That money can cover between 10 and 12 bridges, he said.

Keeping up: "Overall, we've seen York County does a really good job of bridge maintenance," Malesker said. "As they're aging, it's harder and harder to keep up. They're deteriorating quicker than we can work on improving them."

Malesker is a structural engineer with C.S. Davidson Inc., the county's engineering firm. He said locally owned bridges are inspected at least once every two years.

Some bridges, such as those with posted weight limits, are inspected annually, he said.

The Singer Road Bridge in New Freedom, which carries traffic over the rail trail, is inspected annually. The bridge has connection plates similar to those of the Interstate 35 Mississippi River bridge that collapsed in Minnesota in 2007.

In 2009, inspectors replaced three of at least 14 gusset plates, thick sheets of steel used to connect beams to columns. That repair will extend the life of the bridge, which carries about 330 cars daily, Malesker said.

Restricted bridges: Inspectors posted weight limits for 41 locally owned bridges in York County, but all others are open for all traffic.

Weight limits are meant to reduce the stress on the bridge by turning away heavy tractor-trailers, rather than a steady stream of passenger cars, which weigh three tons on average.

As of the end of June, only two of the county's 204 locally owned bridges were closed: Joseph Road in North Codorus Township, which carries traffic over the Codorus Creek, and Hushon Road in Peach Bottom Township, which carries traffic over Fishing Creek.

Five bridges were closed in 2007.

Statewide, 200 locally owned bridges are closed. Washington County leads the state with 13 closed.

"Every bridge has a service life. So, at some point, the materials it's constructed of will deteriorate and it will end its usable service life," Malesker said.

-- Reach Amanda Dolasinski at 505-5437 or adolasinski@yorkdispatch.com.