More than 400 motorists a day will be impacted when a Fawn road is closed long term May 15.

Thompson Road will be shut down between Hemphill and Sun Mine roads to accommodate the replacement of Bull Creek Bridge No. 7, according to Allegheny County officials.

Work is expected to last through December.

Plum-based Pugliano Construction Co. landed the $2.3 million contract, which also includes rehabilitation work on Bull Creek Bridge No. 8.

That work won’t start until spring 2024 — but also will require a closure of Thompson Road near Hemphill Road.

Brent Wasko, public information officer for the county department of public works, said Bridge No. 7 is 55 years old and rated poor.

“When it was built, the original substructure from an 1877 bridge was reused,” Wasko said.

“The current bridge is rated as a 3, meaning it is in poor condition.”

Wasko said the stone abutments are deteriorating at the joints because of advanced age, and the bridge’s beams are nearing the end of their useful life.

The bridge is 54 feet long with a road width of 21 feet.

The new bridge will be slightly longer, 55 feet long, but the roadway will be noticeably wider: 25½ feet.

It will be a pre-stressed spread box beam structure on new concrete abutments.

Work also will include new pavement, guardrails and signs.

Residents who live along the stretch will have access to their homes.

A suggested detour will be posted for others.

It follows Millerstown Road to Millerstown-Culmerville Road, Bakerstown Road, Little Deer Creek Valley Road, Saxonburg Boulevard and back to Dawson Road.

Tawnya Panizzi is a Tribune-Review staff writer. You can contact Tawnya by email at tpanizzi@triblive.com or via Twitter .