When Maryland’s State Highway Administration did a statewide inventory of structurally deficient bridges that were in need of repair in 2015, Frederick County’s 13 were the most of any county in the state.
Four years later, five of the structures have been repaired and are open to traffic, while the others are in various stages of renovation or replacement.
Some of the projects, such as the two bridges that carry Interstate 270 over Md. 85, are highly visible. Others may affect only a relatively small number of drivers in their immediate area.
When Gov. Larry Hogan first came into office, he made repairing the state’s 69 structurally deficient bridges a priority. Most of the deficiencies identified had to do with the bridge deck, SHA spokesman Charlie Gischlar said Friday.
Bridges are evaluated on three elements: their deck, superstructure and substructure.
A bridge’s deck consists of the driving surface, walls, sidewalks, drains and other features. The superstructure is the steel or concrete beams that support the bridge deck, while the substructure includes bridge piers and abutments that support the superstructure.
The most recent information available from the Federal Highway Administration, from the end of 2018, lists 5,357 bridges in Maryland, with 1,757 rated as “good.”
Another 3,326 were rated “fair,” with 274 rated as “poor.”
Massachusetts, with 5,215 bridges, had 1,370 good bridges, 3,364 fair, and 481 considered poor. Montana had 5,265 bridges, 1,605 of which were good, 3,270 fair and 390 poor.
While the phrase “structurally deficient” may bring to mind images of the 2007 collapse of a bridge across the Mississippi River in Minneapolis that killed 13 people, that’s not really the case.
A structurally deficient bridge is one that is structurally safe, but has come to the point that it’s not economical to make minor repairs, Gischlar said.
While some of the Frederick County projects have been finished, others remain in various stages of completion.
A project on Md. 28 over the Monocacy River, which was built in 1931, is undergoing a rehabilitation project, with work being done to the bridge deck, painting of steel, and concrete repair and temporary traffic signals guiding traffic.
The work began in the late summer or early fall of 2018, and is scheduled to be finished this summer.
Meanwhile, a replacement project for the bridge on Md. 140 over Flat Run that began in the fall of 2016 is also scheduled to be finished this summer.
Only some concrete wall work, paving to the bridge’s approach, and landscaping remain to be done, according to an email from SHA.
The project on I-270 over Md. 85 involves an interchange reconstruction and replacement of two bridges built in 1950 with a single bridge.
Begun in fall 2017, the project is scheduled to be finished in spring 2022.
A new Md. 355 bridge over the CSX tracks near Monocacy National Battlefield will replace a bridge built in 1931.
Concrete was recently poured for the south abutment footer, while the project’s contractor is setting forms and placing steel rebar to prepare to pour the concrete for the north abutment footer.
Another bridge on Md. 355, over Bennett Creek near Urbana, will be replaced by late fall 2020, with excavation of a temporary road and utility relocation currently being done.
Work on the bridge, built in 1924, began in fall 2018.
Near Knoxville, work on the replacement of a 1925 bridge over a branch of the Potomac River that began in fall 2018 is expected to be done by early 2020.
The road will be closed and detoured this winter to help move the project along, according to SHA.
The replacement of a bridge on Md. 464 over Little Catoctin Creek should be finished by late this fall, with utility relocations currently underway.
Begun in late fall 2018, the project includes widening the bridge to include shoulders to accommodate bicycles, as well as stabilizing a section of Little Catoctin Creek.
Beginning in July, workers will close and detour Md. 464 until December. Drivers will use a detour on Olive School Road to Md. 180 to Md. 17, with a temporary traffic signal at Olive School Road and Md. 180 until the project if finished.
Meanwhile, bridges on Md. 77 over the Monocacy River; on Md. 194 over Little Pipe Creek; Md. 550 over Israel Creek; on northbound U.S. 15 over Md. 26; and the ramp for eastbound U.S. 40 over the ramp from the westbound lanes to westbound Interstate 70, have all been repaired or replaced.
Many of the bridges that have been repaired were built in the early 20th century, and the projects allowed them to add bike lanes and other improvements, Gischlar said.
“The new bridges will be around for 50-plus years,” he said.