Why would crews use a concrete saw to cut into a freshly repaved road?

That was the question some people asked after seeing workers using saws to cut across Route 309 between Hometown and Tamaqua.

Some people posted online, guessing that the contractors had to tear up the work after making some mistake.

Not true, PennDOT says.

There was no mistake — it was part of the plans from the beginning of the $3.4 million “pavement preservation project.”

Anyone who drove through the construction zone over the last few months can tell you that beneath the new layers of asphalt is a concrete base.

That base, according to PennDOT spokesman Sean Brown, has expansion joints, just like a concrete sidewalk.

“Where there are joints in the slab the contractor is cutting, so the joint matches the concrete slab,” he said.

When you pave over those joints with asphalt, eventually the top layers will crack along those joints. If they crack irregularly, it leads to pot holes and a rougher ride.

So it’s standard practice to cut expansion joints into the pavement right after a repaving project is completed. That work wrapped up Wednesday.

The cuts will be sealed, and hopefully prevent cracking and pot holes.

Work is wrapping up overall on the project, which involved milling and paving a 3-mile section of Route 309. The new pavement stretches between East Rose Street in Tamaqua, crossing the intersection with State Route 54, and ending past the railroad bridge at Grove Street.

Between 12,000 and 20,000 vehicles use the stretch every day, according to PennDOT.

Overall, the project consisted of milling, concrete patching, base repairs, paving, concrete island replacements, minor bridge repair work, guide rail updates and new pavement markings.

Lehigh Asphalt Paving & Construction Co. was the contractor.

“It was a much needed project,” Brown said.