Not long after its opening in the late 1960s, the Lyndon B. Johnson Freeway corridor (Interstate 635) in Dallas experienced explosive growth and quickly exceeded capacity. As a result, planning for an expanded LBJ began in the late 1980s. More than 200 public meetings and three decades later, the project is under way.

The I-635 Managed Lanes project, also known as the LBJ Express, is a $2.7-billion, 13-mile highway reconstruction that will more than double the capacity of the corridor, which spans two municipalities in Dallas County. All of its general-purpose main lanes, frontage and service roads will be rebuilt, and four to six new toll lanes added in each direction. The three-phase project, which began in late 2010, will be completed on time and on budget, says the project team.

P3 Design-Build

In 2005, as the Texas Dept. of Transportation prepared to move forward with construction, projected costs began to exceed the budget, agency officials told ENR. TxDOT changed the design to reduce costs, including moving to an open-air, depressed scheme. At the same time, the agency sought participants for a public-private partnership financing approach. In 2009, the agency chose LBJ Infrastructure Group, led by Austin-based Cintra US and Meridiam Infrastructure, to construct the project as a design-build job under a P3 agreement.

Consortium partners also include the Dallas Police and Fire Pension System and contractor Trinity Infrastructure LLC, which is a joint venture between Austin-based Ferrovial Agroman US Corp. and Houston-based Webber.

The P3 agreement was a combination of public and private funds, including private equity ($665 million), unwrapped private activity bonds made available by the U.S. Dept. of Transportation ($615 million), $496 million from TxDOT and a U.S. DOT Transportation Infrastructure Finance and Innovation Act (TIFIA) loan of $850 million, explains Daniel Filer, Ferrovial vice president of business development. Design-build is ensuring accelerated delivery of the projects, he adds.

Under a traditional TxDOT-funded model, a project of this scope would take about 15 years to complete, Filer adds. Using P3 resources and the ability to design, demolish and rebuild concurrently will allow its completion in five years or less.

The consortium will complete design and construction and continue to operate and maintain the LBJ project until 2061. This project is one of only a few toll-concession, design-build projects around the world where the financing, design, construction, operations and maintenance risks are all transferred to the building team, says TxDOT. The project is 77% complete, averaging more than $50 million per month in construction costs, say agency and building team officials.

Narrow Corridor

Construction of the managed lanes project has required careful planning, given its size and scope, particularly with more than 220,000 cars passing through the corridor every day.