PITTSBURGH (KDKA) — The Port Authority is undertaking a big construction project that impacts many commuters.

The concrete area from the Mount Washington transit tunnel to the South Hills Junction is only a few hundred feet, but the rails need replacing.

“First, they have to dig up the concrete, replace the rail, and repour the concrete,” Port Authority Spokesman Adam Brandolph said.

Working around the clock, the Port Authority hopes to complete the work by Aug. 22nd, but in the interim, all inbound T trains will be detoured through Allentown.

“When you have embedded track that is driving with private automobiles, you have to deal with traffic,” Brandolph said.

Commuters coming from the South Hills to Station Square have to ride to the First Avenue Station and catch an outbound train back across the river.

Brandolph said to expect commuting delays of 10-15 minutes in the mornings and even longer delays in the afternoon because outbound trains are still using the transit tunnel and need to cross through the construction zone.

“They might have to wait for the crews to move around and get out of the way.”

This construction is going to impact a lot of commuters.

“About 10,000 light rail riders,” Brandolph said. “It’s all riders on our entire light rail system and it’s about 5,000 bus riders on an average weekday.”

Routes, 39, 40, 41, 44, and Y45, Y46, Y47, and Y49 are all being detoured and won’t have access to the South Hills Junction.

The Port Authority says if you want to find out the impact on the route, click here.

You can also call the customer service center at 1-412-442-2000.