Current Crosstown Expressway has safety issue historyPosted: June 26, 2011
This piece was part of a double truck piece in The Oklahoman Sunday edition, June 26, 2011. To see the PDF of this piece, with accompanying photographs and timeline, click here. View the other page here.
By: Brandon Goodwin
A bridge is not something motorists want to see through.
Yet that is a regular occurrence on the Interstate 40 Crosstown Expressway, a two-mile elevated highway through Oklahoma City that frequently drops coffee table-sized chunks of concrete from its deck, exposing naked rebar and the ground below.
Emergency crews rush to the bridge to repair these holes about 20 times a year, creating a quilt of patches designed to keep the bridge usable until it is replaced with a new section of highway next summer.
For years, motorists have raised concerns about the integrity of the expressway.
Oklahoma Transportation Department officials said the bridge has regular inspections and is safe.
“If there was any indication that the condition of the bridge was dangerous, we would not have traffic on the bridge,” Division Engineer Paul Green said.
But concerns about the bridge goo deeper than its surface.
The structure’s support beams are known as “fracture critical,” an outdated design technique that means if one support beam fails, the entire bridge section could collapse.
The I-35W bridge that collapsed in Minneapolis, Minn., in 2007, killing 13 people, was a fracture critical structure.
Field Construction Engineer Anthony Echelle said the Crosstown Expressway bridge has 300 fracture critical points.
It was built to modern design standards when it opened in 1966, but this type of structural design was thrown out in the 1970s in favor of designs that offer secondary support beams.
The last incident concerning a fracture critical point on the Crosstown was in 1989.
Inspectors found the spot before it failed and closed the bridge until it was repaired.
Regular inspections also report corrosion and rusted beams.
Officials said issues concerning the safety of the bridge are addressed.
Other issues are deferred since the bridge’s days are numbered.
“We are doing everything to see that is is safe,” said Terri Angier, spokeswoman for the Oklahoman Transportation Department. “But not past the point of wasting taxpayer dollars.”
The structure will be replaced by a new section of Interstate 40 next summer that will be five blocks south of the current expressway.
The state spends more than $1 million a year on preventative maintenence of the roadway, Echelle said.
Costs of spot maintenance are cheaper than projected costs to redeck the bridge. Additionally, the major impact to traffic to overhaul a bridge that will close in a year is not necessary, Echelle said.
Some of the degradation of the bridge comes from high amounts of traffic. Currently, the bridge carries about 120,000 vehicles a day, 50,000 more than it was designed for.
The bridge also lacks shoulders, and offers little merging room.
“If you have a flat tire, there is little room to pull over and have car trouble,” Echelle said.
“Thats just another reason why we are eager to get traffic off that old bridge,” he said.