No Shortage of Detours, Closures and Traffic in the Days Following Bridge Collapse
A Port Authority bus, which went down with the bridge was lifted out the ravine Monday afternoon.
Days after the collapse of the Fern Hollow bridge in the East End, a massive crane carefully lifted a Port Authority bus high into the air and back onto solid ground late Monday afternoon. Images of the surreal scene soon flooded social media.
The bus was removed a few hours after most of Frick Park was reopened except for the areas closest to the scene of Friday’s bridge collapse. Tranquil Trail will be closed within a 100-yard perimeter of the collapse site. Undercliff Trail also remains closed.
Inspectors for the National Transportation Safety Board deployed a go-team over the weekend to begin sifting through the rubble, and recovery workers have started setting up the equipment they’ll need to remove debris like vehicles — including the downed Port Authority bus left dangling over the edge.
While 10 victims sustained injuries — including two who suffered fractured vertebrae — there were no deaths, and only four total hospitalizations. Even as the injured continue to recover, it’s a number that could’ve been higher if it hadn’t happened so early on a morning when many schools had announced two-hour weather delays.
The downed bridge has also led to considerable disruptions for those who rely on it as part of their daily commute. More than 14,000 cars travel over the bridge each day. It was the main thoroughfare for public transit, too; two Port Authority bus routes — the 61A and 61B — cross it more than 200 times per day combined.
Over the weekend, the bus routes were detoured along South Dallas Avenue to Penn Avenue and through Wilkinsburg before emerging on South Braddock Avenue to rejoin the original route. Regional traffic should use the Parkway East instead of Penn Avenue, and local drivers and residents are instructed to follow South Dallas to Penn Avenue to South Braddock.
At least 100 feet of street parking has also been temporarily eliminated next to the Forbes/Braddock playground to improve traffic flow.
On Sunday, Mayor Ed Gainey signed a Declaration of Disaster Emergency for the city. This will increase the availability of federal funds, facilitate closer coordination between PennDOT and the Department of Mobility and Infrastructure and expedite the process of cleanup and reconstruction of the Fern Hollow bridge, according to a press release.
“As the City of Bridges, we know how critical our infrastructure is to working families. They are the connectors to jobs, to schools, to child care and more,” Gainey said in a statement. “With the support of our county, state and federal partners, we will build back better.”
But building a permanent replacement for the bridge could take years. The construction of the Greenfield Bridge, completed in 2017, marked the last major span construction in the city. It took two years — not counting the time spent on design work.
Pennsylvania Gov. Tom Wolf said it was “a miracle” that no one died in the collapse, and John Fetterman, Pennsylvania’s lieutenant governor, called the sight of the crumbled bridge “surreal.”
“I just want these bridges fixed as a dude who drives his kids over them almost every day,” he wrote in a Jan. 29 blog post on Medium. “And frankly, I don’t know how anyone can look at today’s disaster and think we can afford to wait any longer on investing in our infrastructure.”
A total of 80 Allegheny County bridges owned by the City of Pittsburgh and other municipalities are also listed as being in poor condition, as are 96 bridges owned by the state. Those 176 bridges make up about 11% of the county’s 1,583. More than 7% of all bridges in the U.S. have been given a poor rating, according to National Transportation Board’s Chair Jennifer Homendy. In Pennsylvania, that proportion is almost 15%.
It isn’t yet clear what exactly caused the bridge in Frick Park to fall, and experts say it could be months or even a year before a definitive cause is released.
At a Jan. 29 media briefing, Homendy said the agency has a long and technical investigation ahead of them.
“We’re looking for things like signs of corrosion, signs of fatigue cracking,” she said. “We are going to put this bridge under a microscope. We’re going to look at the entire history of this bridge … up until the day of the collapse.”
Homendy also said a preliminary report from the NTSB will be ready in about 10 days.
“We hope to conclude everything and have a final report out [in] between 12 to 18 months, and we hope it’s less,” she said.
Information from the nine cameras on the Port Authority bus will be analyzed, too, along with inspection reports, change over time of loads and types of vehicles on the bridge and the impact of weather and road treatments.
“The use of road salt most certainly accelerates corrosion-related degradation of both steel and concrete structures,” said Kent Harries, professor of civil and environmental engineering in the Swanson School of Engineering at the University of Pittsburgh. “Indeed, the use of salt has been generally reduced over the years. There are alternatives that are used in many instances. Some of these, however, are rather more costly (others not).”
Salting was cited as one of the factors in the collapse of an overpass onto the eastbound lanes of Interstate 70 back in 2005, along with hits from trucks and simply time — bridges can die of natural causes, too.
The problem is that, like the signs say, “bridge ices before road.” Harries said bridges have air circulating beneath them and don’t have the benefit of the thermal mass of the solid body beneath a road. Without salt, the icy surface of a frozen bridge could cause drivers to veer off into the guard rails, or into each other.
“Salt is seen, I suppose, as a necessary evil to help maintain the safety of the traveling public,” Harries added.
Harries also said that bridges aren’t necessarily more likely to collapse in the winter. Many environmental factors, he said, can affect how a structure behaves.
“Certainly temperature is one. Extremes of temperature and rapid temperature changes can impact a structure’s performance,” he said.
All are factors that are considered during the design phase of construction.
Pittsburgh Public Safety announced Monday afternoon that a public observation area for the Fern Hollow collapse site will be established on the Squirrel Hill side of the bridge. It will be open from dawn to dusk, with officers in the area at all times, and it can be accessed by walking down Forbes Avenue from South Dallas. Onlookers can park at the Frick Environmental Center, officials said.
Folks are still reminded to avoid the closed-off perimeter of the collapse site because of an array of potential hazards.