Delaware’s bridges more sound than national average

DOVER — Delaware is better than the national average in the condition of its bridges.

About 5 percent of the state’s 1,714 bridges are rated as structurally deficient, whereas slightly more than 9 percent of the bridges nationwide are deteriorating, according to the Delaware Department of Transportation and the American Road & Transportation Builders Association.

Delaware has far fewer bridges than most states, and it evidently does a good job of keeping them up-to-date.

The bridge at Barker’s Landing

Not every bridge is something a Delawarean can walk or drive a car over, however. DelDOT is responsible for overseeing two types of bridges, including drainage pipes and walkways. While pipes and pedestrian paths may differ from the general concept of what a bridge is, they are defined as state-length bridges.

General bridges are considered to be structures that are at least 20 square feet, have a height of at least 4 feet and are 20 feet longer or more. Pipes that do not meet those guidelines do not fall into that category.

Bridges are inspected every other year, and pipes and walkways are generally examined every four years. DelDOT ranks every bridge on an annual basis, with a formula placing them on the list depending on their conditions.

“We take the data based on those inspections and we prioritize bridges for work based on the data, and our goal is to have less than 5 percent structurally deficient bridges,” DelDOT state bridge engineer Barry Benton said.

Bridges in need of work are handled in different ways: Small fixes can be done by DelDOT, while larger issues are contracted out.

Minor problems can include fixing potholes, sealing concrete and repairing drains. According to Mr. Benton, Kent and Sussex counties have many metal pipes that are large enough to be classified as bridges and often need small repairs due to rust.

The agency has four contractors it regularly reaches out to for projects — one above the Chesapeake & Delaware Canal, one in southern New Castle County, one in Kent County and one in Sussex County.

DelDOT is currently in the “heart” of construction season, bridge management engineer Jason Arndt said.

Delaware’s current transportation spending plan authorizes about $36.9 million in state money for bridges through the fiscal year ending June 30, 2020. About $102 million in federal dollars is also authorized.

That plan includes 11 Kent bridges that are set to see some type of work over the next three years.

At the state and local level, bridges do not go through the same review process as roads when it comes to fixes. The practice enables DelDOT to make needed repairs quicker.

In Kent County, DelDOT maintains 384 bridges, of which 303 (79 percent) are “good,” 63 (16 percent) are “fair” and 18 (5 percent) are “poor.”

Bridges today are built to last at least 75 years, DelDOT bridge design engineer Jason Hastings said.

As of 2015, the average age of a Delaware bridge was about 43 years. Forty-eight bridges were built at least a century before.

One of Delaware’s bridges was in the news in 2014 when the Interstate Highway 495 Bridge was shut down entirely for most of June and July after several support columns were found to be tilting from large piles of dirt resting next to them.

The dirt was removed and the pillars repaired, with the state seeking federal funding to help cover costs.

About 90,000 vehicles take the 4,800-foot bridge daily, according to DelDOT.

Despite occasional large-scale headaches, DelDOT’s bridge experts are proud of the state’s success in maintaining bridges. Mr. Benton noted Delaware ranked well in the American Road & Transportation Builders Association’s list. In fact, by percentage of deficient bridges, Delaware was ahead of 42 states.

“We’re functioning about the level that we want to be functioning at,” Mr. Benton said. “There’s always going to be bridge work to do.”

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