A few taps on the behind is probably not going to get a crew member to move any faster. The fact they are working out of a ketchup bottle doesn't matter, either.
The Rte. 28 corridor--a squeezed four-lane road featuring the Allegheny River on one side and a steep hill capped with historic landmarks on the other--is the salty piece of the Pittsburgh transportation system. In an area famous for its sweet, red condiment (Heinz), bitterness is an overpowering emotion during the morning and evening rush.
Tight quarters and heavy traffic are just two reasons why simple maneuvers will not work when the time comes to reconstruct a two-mile stretch of Rte. 28. Predominantly a north-south route, the corridor filters traffic into I-279 and I-579 which provide connections to sporting and cultural events in the downtown area and to the airport. Compounding the traveling numbers are the 31st and 40th Street bridges over the Allegheny.
Before the first construction horse is dropped, Pennsylvania Department of Transportation (PennDOT) officials are looking at three goals: high speed, high quality and high safety.
"This two-mile stretch is the missing link in a limited access highway system," PennDOT Senior Project Manager Jeff Clatty told Roads & Bridges. "There are the 31st and 40th street bridges and two major traffic light intersections. It's probably one of the more congested areas in our highway system."
Escaping death
Accelerated construction is beginning to pick up supporters across the country. The whole concept of building faster for the sake of the daily commuters started long ago, but only recently has the blueprint of sound strategy generated discussions from some of the leaders of the industry.
The American Association of State Highway & Transportation Officials, the Federal Highway Administration and the Transportation Research Board A5T60 Task Force combined funds and resources to conduct two pilot workshops titled "Accelerating Construction Technology Team Workshops." The purpose was to explore innovative ways that transportation corridor construction could be brought to full service quicker and with less impact to the traveling public. The workshops, hosted by the Indiana DOT (INDOT) and Penn-DOT, brought together a national team of recognized experts (the Accelerated Construction Technology Team) and included plenary sessions, breakout sessions, skill set interaction and follow-up status reports.
Coincidentally, Indiana and Pennsylvania also were chosen as the pilot states of this accelerated construction effort.
"When they decided to go ahead and designate pilot projects some of the people on the task force were from Pennsylvania and Indiana," said Clatty. "They had ideas of a project in each of their states that would possibly fit the bill as pilot projects."
The experimental project in Indiana is the improvement of I-465 from Rte. 67 to 56th Street. This project includes the addition of travel lanes and the major modification of interchanges for the entire west leg of Indianapolis' I-465. Construction is scheduled to start in 2005 and end in 2010.
Rte. 28 in Pittsburgh is a four-lane, undivided, free access highway holding an average daily traffic of 56,000 at the southern end and 70,000 at the northern end. Proposed improvements include: elevating and bifurcating Rte. 28 to accommodate widening to four 12-ft lanes with shoulders and a median barrier; providing grade-separated interchanges at the 31st and 40th Street bridges; and realigning Rialto Street to a "plus" intersection with the 31st Street bridge.
"There are quite a few accidents on this corridor," said Clatty. "The media at times has dubbed this ?The Death Stretch' because with the narrow lanes and the high volume there have been a number of head-on accidents over the years."
With the accelerated construction plan in place, PennDOT hopes to achieve the following goals:
* Complete construction in two years;
* Reduce time to bidding from fall of 2006 to fall of 2005;
* Maintain traffic flow of 35 mph during construction;
* Expedite right-of-way acquisitions and utility relocations;
* Facilitate railroad coordination;
* Provide long-life pavement; and
* Produce a plan that is aesthetically acceptable and constructible.
The Rte. 28 corridor, however, is loaded with sensitive subjects.
First, there's the Pennsylvania bedrock, which isn't the most stable on earth. The steep hillside along the "north" end of the highway contains rock cliffs and supports the Troy Hill neighborhood of Pittsburgh. Repairing this section will call for geotechnical treatments.
Based on preliminary design and the current alignments, Michael Baker Jr., under contract to complete preliminary engineering studies, expects the project to involve five bridges with 21 substructures, 18 retaining walls totaling five miles in length, eight rockfall fences and three landslide-prone slopes.
The project also will impact over 200 properties and include the relocation of some residences and businesses. A park, cemetery, industrial park and historically eligible properties, including the St. Nicholas Church, will be affected as well.
Utility relocation will be critical to the task at hand. Utilities located within the Rte. 28 corridor include: an existing water line with numerous supply lines; extensive sanitary sewers including an interceptor line; natural gas supply lines including a transmission line, electric and telecommunication lines. The existing sanitary sewers are a combination sanitary/storm water system that will have to be separated. The existing combination system could be maintained to carry the existing sewage and the new highway storm water system will require new outlets running under the railroad and trail to the Allegheny River.
Detours are limited, which will make effective traffic management crucial. Pittsburgh does not have a local roadway network serving the Allegheny Valley that provides good north-south parallel access adjacent to this project. The local roads are one lane in each direction and have parking on one or both sides with several intersections and driveway access. One of the main project challenges will be to implement methods to reduce the amount of traffic diverted to local streets.
Don't wait too long
Perhaps the key to accelerated construction is advanced execution. In the case of Rte. 28, expediting right-of-way acquisitions and utility relocation planning is a break from the norm for PennDOT.
"Generally, we don't have a right-of-way plan until we move into final design," said Clatty. "We do some utility coordination, but the details of that type of relocation and finalizing of those issues often doesn't happen until we're in final design."
PennDOT cannot do any specific right-of-way acquisitions until the NEPA document is complete and approved, but there are a couple of plans in the works. According to Clatty, total takes (those properties involved in acquisition and relocation) are pretty clear, and because it is a narrow corridor any of the alternative plans would carry strikingly similar impacts.
"As soon as we have the environmental document we could finish processing the right-of-way plan and within a few months start making offers."
With the safety concern of moving on and off the Rte. 28 corridor, most businesses and homeowners actually approve of any relocation.
"That's an advantage because with commercial properties and relocations it can take a long time to settle those claims," noted Clatty.
Acquisition involving approximately 239 properties will be required for this project.
PennDOT, however, admits that the environmental review process with some of the properties will have to take its normal time. The St. Nicholas Church is eligible for the National Register and is an ongoing concern. The options are relocation or demolition if an alternative that avoids the church is not advanced to construction.
"The community would like to see the church stay or even moved," said Clatty.
The Pittsburgh Diocese may deliver the ultimate solution. The small parish is struggling financially, and if the Diocese decides not to maintain it PennDOT will be able to demolish the structure after a detailed recordation of the church and its history. A sister church located 11/2 miles away in Millvale would welcome the St. Nicholas parish.
The Millvale Industrial Park is another community cornerstone along Rte. 28. Originally a brewery, the park has served as an important site during the development of Pittsburgh.
PennDOT is looking into establishing a task force to deal with the utilities. The main water line makes the relocation job a major concern. Clatty hopes officials will be able to identify a "utility corridor," one that will be able to house all the water, sewer, gas, electrical and telecommunication lines.
Early traffic treatments should ease congestion tension just days into initial construction. PennDOT plans to eliminate the two traffic signals at the 31st and 40th Street bridges. This maneuver alone should keep traffic moving at 35 mph throughout the entire work zone.
Due to configurations, there are four signals tied together at the 31st Street bridge. During work, the bridge and Rialto Street will be closed thus eliminating the need of the electronic stop-and-go.
Crews will actually reconstruct the Rialto Street intersection, where traffic backs up regularly. Today, Rialto Street is offset by 60 ft from the end of the 31st Street bridge. On the bridge approach there is a ramp that comes down to River Ave., and another ramp passes over the back channel of the Allegheny River to Washington's Landing--an island that has turned residential and commercial. Here is where the four signals link, causing delays on the Rte. 28 corridor. Plans call for putting a slight S-bend into Rialto Street so it lies opposite the
"You're really only removing one leg of the problem, but the signal will be less complex," said Clatty.
Over on the 40th street bridge motorists wanting to make a left turn onto Rte. 28 will take a detour to the Millvale interchange, where they'll make a loop and come up to the ramp which empties into the southbound direction of the corridor. Since Rte. 28 traffic will no longer have to yield to left turners off the bridge, the traffic signal will become obsolete. Future construction will call for an at-grade intersection for the 40th street bridge. This will be placed between north and south Rte. 28 traffic, which is set to be elevated and separated. Local traffic on the bridge will use the intersection and ramps to access Rte. 28., while through traffic will bypass the intersection.
Along the hillside
In order to accommodate the new ramping system at both bridges, the new south Rte. 28 will be elevated (as high as 18 ft at the 31st streetbridge). This will require the contractor to deal with the steep hillside. The south lanes will be moved and tucked into the tricky terrain.
"The intersections that the ramps will service at the two bridges will be in the middle. The north (Rte. 28) lanes will pass under the bridge and the south lanes will be above. The ramps will come down from the south and up from the north to that intersection in the middle," said Clatty.
For stabilization purposes, 10-12-ft walls will be installed along the south lanes. In order to accelerate the installation process, PennDOT is looking into soil nails walls.
"It's basically a tie back anchored in rock," said Clatty. "You have a concrete pad of sorts and it lays in against the slope, and you have the rock anchor tie back that pulls it in."
Instead of one continuous wall, the soil nails will be spaced apart. The pressure from each wall will help stabilize a larger area, and also allows for aesthetic enhancements. The strong anchor system would eliminate the need for deep foundations.
"You can plant around them or hide them," said Clatty. "They are aesthetically bit less obtrusive."
The walls can be installed with smaller equipment, further making it a more appealing option in the tight quarters of the Rte. 28 corridor.
All in all, the combination of installing the soil nails and cutting back the slope to appropriate grade should stabilize the hillside along south Rte. 28.
Coming in and maintaining the road every five to 10 years would tarnish the reputation of accelerated construction. PennDOT wants to finish fast and stay off as long as possible, and for this reason is investigating pavement with a 50-year design life. This will probably call for a thick concrete base covered with a sacrificial surface layer (21/2-in. binder, 11/2-in. wearing surface). The top course would be Superpave.
If maintenance is necessary, crews could come in at night and mill the surface or all the way down to the concrete base.
A full asphalt and full portland cement concrete design also is being considered.
Safety built in
Working at a faster pace only increases the risk of accidents. For this reason, PennDOT will specify certain safety standards in the Rte. 28 corridor project.
There is talk about going to three lanes during peak travel times, with the center one reversible during construction. This would provide the contractor with a additional space, which could be used for a haul road or for the installation of a rock/debris fence.
A full-time health and safety officer on site will be another requirement, and worker fatigue will be addressed in the specs. Clatty talked about the use of multiple shifts and required vacation.
When dealing with geotechnical treatments and wall installation on the hillside, the suggestion is that the crew should work from the top and build down.
"A lot of that can be done under traffic without restriction. There would be some areas where they can lodge in and work off a shelf," added Clatty.
