Texas Feeling Reverberations From Minneapolis Bridge Collapse

DALLAS — In Texas, where traffic on aging highways is increasing rapidly, last week’s collapse of the Interstate 35W bridge in Minneapolis had quite an impact. At the southern end of Interstate 35, Texas shares maintenance of bridges over the Rio Grande with Mexico, a source of so-called NAFTA traffic that has added stress to the roadways for the past 13 years. The North American Free Trade Agreement traffic has also spurred development proposals for controversial public-private projects, such as the Trans Texas Corridor, envisioned as a $150 billion network of highways and rail lines to relieve pressure on I-35. With the state population rising by 1,000 residents per day, the Texas Department of Transportation is struggling to keep up with demand for new highways while maintaining those that are bearing more cars and trucks. “In the past five years, we’ve shifted more than $6 billion out of new construction to maintenance,” said TxDOT spokesman Chris Lippincott. “It’s tough to strike that balance between new projects and maintenance. But we’re not going to let the system crumble around us.” A further drain in resources comes from rescissions of federal highway funds as Washington seeks ways to stanch the flow of red ink amid war and reconstruction projects in Iraq and Afghanistan. In March, TxDOT had to adjust its spending plans after the federal government ordered the state to return $290 million of its allotted highway funds. In the previous 15 months, the state had returned $305 million. “The rescissions are just irresponsible,” said Sen. John Carona, R-Dallas, chairman of the state Senate Transportation and Homeland Security Committee. “Each rescission amounts to a broken promise.” Now, Texas expects to lose about $22 million due to the catastrophe in Minnesota. The federal money that was to have covered the cost of repairs from flood damage in El Paso is needed more urgently in Minnesota, state officials explained. Texas Transportation Commissioner Ted Houghton told the El Paso Times that the diversion was “the right thing to do. We’re not complaining.” Texas will cover the loss from its own emergency fund, officials said. The $22 million is expected to be the state’s share of $250 million likely to be appropriated by Congress for the Minnesota recovery. While officials in Texas and other states issued immediate reassurances about the safety of local bridges last week, the bridge’s 65-foot plunge into the Mississippi River dramatized the peril of deferred maintenance. Texas has more bridges than any other state, including 18 that use the same steel-truss design as the I-35W span over the Mississippi River in Minnesota. “I think the current bridge and infrastructure in Texas are sufficient, but that won’t be the case long if we don’t put sufficient money into it,” Carona said. “The fact is that bridges fall down,” said Jean-Louis Briaud, manager of the Texas Transportation Institute’s geotechnical and geoenvironmental program. “Out of 600,000 bridges in the U.S., 1,500 have collapsed in the last 50 years.” That translates to 30 bridges falling per year. But Briaud notes: “The trend is not constant. It’s decreasing. So, that’s the good news.” By far the largest cause of bridge collapse is “scour” or erosion around the base, which accounts for about 60% of falling bridges, according to Briaud. A distant second cause of collapse is ship impacts at 12%, followed by earthquakes at 2%. A recent study of Texas’ 50,183 bridges indicated that 600 are on the “scour-critical list,” Briaud said. Nationwide, 25,000 are scour-critical, he said, while adding that there are plenty of unknowns and that the criteria used to classify a bridge in the category is highly conservative. “For 100,000 bridges, we don’t know what the foundation is,” Briaud said. “We are developing a simple methodology that will be much more accurate in predicting erosion around bridge pilings. With research, we can more accurately determine those bridges that are indeed at the greatest risk.” The Texas Transportation Institute and TxDOT became particularly concerned about scour due to recent heavy rains and flooding around the state, which tends to increase erosion. A 2006 study found that 2% of state-owned bridges in Texas were structurally deficient, including 12 in the Coastal Bend section of the Gulf Coast near Corpus Christi. The 10-county coastal region that includes Nueces, Aransas, Kleberg, and San Patricio counties had 1,270 state-owned bridges, many crossing ship channels or bays. The worst recent bridge disaster in the South Texas area occurred nine days after the terrorist attacks of Sept. 11, 2001, when a tugboat and four barges knocked out support columns for the Queen Isabella Causeway that linked the mainland and South Padre Island. Eight people died when their cars plunged 80 feet into the water. Less than 75 days after Gov. Rick Perry issued a disaster declaration, the causeway was repaired, funded by 80% federal money and 20% state funds. While Texas had the resources to cope with that event, constant wear and tear is overwhelming the state’s ability to keep up with demand for new highways, even after the Legislature doubled TxDOT’s bonding capacity to $10 billion in the past session. Additional financing is available from private sources, but lawmakers last spring placed a barrier to that revenue source in the form of a two-year moratorium. Sen. Carona also worked to take away a private contract on a $5 billion State Highway 121 toll project from a Cintra/JPMorgan consortium in favor of the public North Texas Tollway Authority. Under Carona’s SB 792, regional toll agencies get priority over private entities. To solve the growing funding crisis, Carona would prefer to raise the state fuel tax to match the rate of construction costs and halt diversions of the fuel tax revenues to the Texas Department of Public Safety and other agencies not directly involved in transportation construction. “The list of diversions is growing at an alarming rate,” Carona said last week. “We’re diverting $1 billion a year to the Department of Public Safety.” At present, there are no privately owned highways or bridges in Texas. But if and when that happens, safety will be an issue, as recent debate in the Legislature indicated. While the state is responsible for inspecting all public bridges, the private operator of a toll road would be responsible for hiring engineers to inspect their roads and bridges. “We would have the right to inspect the bridge or audit their inspection at any time,” Lippincott said. Although inspections and new technology will help keep bridges standing, there are always uncertainties, Briaud pointed out. “No matter how a bridge is constructed, obtaining a 0% risk of failure is not possible,” he said. “There are simply too many variables. But with research, we can more accurately determine those bridges that are indeed at the greatest risk.”