The Pennsylvania Turnpike has produced several works of art as part of the $193.6 million Allegheny River Bridge replacement in Harmar and Oakmont.

Three huge walls along the shoulder of the eastbound lanes near the bridge have been etched and stained in hues of brown, tan and olive, with layers of black to resemble coal seams and various cracks and faults carved in for added effect.

Like any artistic venture, the walls have produced a spectrum of opinions. Some like them, and others wonder if a king's ransom of toll dollars was squandered in creating them.

The walls were needed to hold back the slopes that hug the turnpike in that area. The wider, realigned turnpike had to fit into a narrow corridor between the University of Pittsburgh's Applied Research Center, a railroad line, a cemetery and Oakmont Country Club, said Craig White, project manager with McTish, Kunkel & Associates.

The etching and staining was a flourish, part of what turnpike spokesman Tom Fox called an effort to blend the highway with its surroundings as it is rebuilt.

Officials estimated the cost at less than $250,000, or about 0.13 percent of the project total.

"You take a look at what fits in best with the surrounding community instead of just throwing up this giant gray wall," said John Pavlovich, a turnpike project manager. "We've gotten, in general, very favorable comments on it."

In fact, Mr. Pavlovich noted that his wife seemed more taken by the walls than the massive twin-span bridge that is the project's centerpiece.

Two walls -- one below Pitt's U-PARC facility and another below the 12th green of the storied golf course -- are called soil nail walls.

As workers dug away a slope to create the sheer wall face, they inserted thousands of "nails" -- 1-inch diameter steel bars coated with epoxy that are driven in at an angle and surrounded with grouting.

"I think of it as just stitching the hillside together," Mr. White said.

The wall was then draped with mesh and steel reinforcing bars and shored with a layer of shotcrete, which is a type of concrete sprayed on at high pressure. The outer 2 inches of the material became the canvas for an artist who carved the seams, crevices and fault lines using a variety of common garden implements -- including rakes, shovels, tree trimmers, brooms and brushes.

While guided by conceptual drawings, the artist, Richard Trible of Cemrock, a subcontractor on the bridge job, pretty much designed as he carved. Unbeknownst to project managers, he also etched at least a half-dozen keystone shapes, which are used in the turnpike's logo, into the hillsides. Motorists are unlikely to spot them unless they're stuck in a traffic jam.

The staining was applied by Rodney Ray of Bella Vernici, another subcontractor.

The bridge replacement is part of a total reconstruction and widening of the turnpike between miles 46.56 and 49.54.

The eastbound span opened in October. The westbound span is scheduled to open next fall.

The existing bridge, built in 1950, will be demolished.

Also part of the project was replacement of the Gulf Lab Road overpass. The road, closed for two years, reopened recently.

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