Amid a maelstrom of mud and machinery, the new Route 28 is starting to emerge.
Construction crews this week are paving new southbound lanes, starting at the 40th Street Bridge, that will accept their first traffic on Saturday. The lanes parallel a towering, 1,620-foot-long retaining wall built into the side of Troy Hill. It is made of concrete stamped in a block pattern and stained an earthy brown.
"For the first time, people will be driving on smooth, new asphalt," said Dan Cessna, District 11 executive for the Pennsylvania Department of Transportation, during a tour of the construction site on Tuesday.
Near the 31st Street Bridge, workers poured the concrete deck on a ramp that eventually will allow northbound motorists to exit to the bridge. The structure of the new on-ramp from the bridge back to Route 28 also is in place.
But the most breathtaking work will come next year -- a massive excavation that will lower the Route 28 mainline by 22 feet, sweeping it under the intersection. While that is done, northbound traffic will be shifted to the new off- and on-ramps.
In addition to ever-changing construction scenery, drivers will see a variety of traffic patterns as the project marches toward completion in late 2014.
From 8 p.m. Friday until about 5 p.m. Saturday, southbound traffic will be restricted to the bypass lane at the 40th Street Bridge and will not be able to turn onto the bridge. After that, the bypass lane, charitably called the "express lane" by some, will close.
Southbound traffic will shift to the newly paved lanes for about a half-mile after passing the bridge, eventually returning to the existing lanes.
The new pattern has a signalized left-turn lane at the 40th Street Bridge. The two through lanes will have no signal.
Mr. Cessna said the new configuration eliminates the split where drivers had to decide whether to take the bypass lane or bear right to have access to the bridge. "We expect traffic inbound to be a little smoother. People aren't going to have that decision point," he said.
Northbound traffic, limited to one lane, will not change for now. The northbound ramp to the 40th Street Bridge will remain closed until later this fall.
The overall project, being done in five phases, stretches from Chestnut Street on the North Side to beyond the 40th Street Bridge in Millvale. Grade-separated interchanges at 31st and 40th streets will eliminate signals for through traffic. Northbound and southbound traffic will be separated by a concrete barrier rather than just yellow stripes. That and elimination of the traffic signals should reduce the number of crashes, Mr. Cessna said.
"That's probably the biggest [benefit]," he said.
Another dividend is replacing the blight that lined Route 28 with "a dramatic gateway to the city," Mr. Cessna said.
PennDOT has awarded $86 million in construction contracts and $37 million of work has been completed to date, he said.
Jon Schmitz: email@example.com or 412-263-1868. Visit the PG's transportation blog, The Roundabout, at www.post-gazette.com/roundabout. Twitter: @pgtraffic.