Flurry of steel girders and concrete beams marked interchange
The completion of a major interchange in Houston this month gives Texas Dept. of Transportation officials new confidence in techniques for building what will be one of North America's widest highways ever. A hefty incentive program plus a rare lane rental method spurred Williams Brothers Construction Co., Houston, to complete the Interstate 10/610 interchange in less than four years and win an $11.4-million bonus.
The $263-million interchange is the largest of ten sections along the $2.7-billion I-10 Katy Freeway corridor, currently under reconstruction and expansion to as many as 18 through lanes plus as six auxiliary lanes. Its completion gives Texas Dept. of Transportation officials confidence that the incentives and corridor-wide project management method is working. "It's not the first time we've had high incentives," says Clifford Halvorsen, TxDOT area engineer. But it is the first time incentives have been paid for various project milestones in such great numbers, he adds.
Interstate 10/610 interchange is biggest piece of Katy Freeway job
When U.S. Rep. John Culberson (R) earmarked money in 2002 for the megaproject, it came with the mandate to build it as fast as possible. TxDOT had to act quickly and get it started, he says. So TxDOT hired Parsons Brinckerhoff, New York City, as program manager. "Our resources were not such that could handle the time frame and enormity of the job," he says. The 23-mile stretch handles more than 200,000 daily vehicles; sections are expected to handle almost 300,000 a day in the next 20 years.
"Until recently, this approach and use of incentives was uncommon in Texas," says David Milner, PB program manager. "But with the success of the I-10/I-610, our engineers and colleagues within Texas DOT expect similar approaches be implemented on major projects, such as reconstruction of the US 290 interchange at I-610."
The job would normally take two to three years to design, but here it took two years, says Ron Kline, project manager for lead designer Reynolds, Smith and Hills, Inc., Tampa. "It led to a lot of trying times and long hours. We had to redesign things around pending rights-of-way acquisitions."
He recalls: "A lot of utilities waited to be relocated, and you had to work around that. This project waits for nobody." Halvorsen says that corridor-wide, ROW acquisitions cost approximately $500 million and utility relocations cost about $365 million.
Williams Bros. built eight connector ramps, a dozen steel box girder or concrete box girder bridges, and three miles of mechanically stabilized earth walls or drilled shaft walls. Crews set beams, poured decks and did everything possible during weekend closures, helped by mostly cooperative weather, says project manager Eric Sommer. If a utility relocation or acquisition got held up in one area, "we worked anywhere else we could to make up for those areas," he says. "It was like working with one arm tied behind your back."
Contractor faced hefty fines or bonuses depending on when lanes
The total incentives include $700,000 for unused hours allowed under the lane rental agreement. TxDOT has used the method once before on the Dallas High-Five project, but refined it here. "You have to watch those clauses, because if they are too prohibitive, you'll scare away contractors," notes Halvorsen. During the design phase, "we got together and thought about all the different types of work the contractor would need to shut down the mainline for–demolition, detours, striping, hanging beams, pouring decks," he says. "We came up with a certain number of hours that he would need, then applied a dollar amount per lane per hour and multiplied it out."
For example, if Williams closed one lane of I-160 during peak hours on a weekday, he would pay a much as $13,800 per hour (depending on direction), because that included no credit hours. But if crews closed a lane between 9 p.m. and 5 a.m., they had unlimited hours during the course of the project to work in that lane during those hours. If crews waned to close three lanes in one direction between 9 p.m. and 5 a.m., they had a total of 240 hours over the project's course. Then the contractor would have to pay as much as $13,700 for each additional hour. But as it turned out, "we will receive a $700,000 incentive for not utilizing all the closure times available," says Sommer.
Various incentives for contractors on the 10 sections add up to about $66 million, says PB's Milner. The whole corridor is more than 75% complete, with one final contract for paving markings to be let next year. The new freeway will include toll lanes, operated by the Harris County Toll Road Authority, in the median of the existing interstate. What started off as 11 lanes plus two frontage roads in each direction will end up in at least four lanes in each direction, plus four managed toll or high-occupancy vehicle lanes and three frontage road lanes, Milner says.
Such road expansion inevitably caused controversy. But Milner notes that the public voted for the freeway expansion in 1996. And Halvorsen adds that a majority "wanted this built 10 years ago."