Project Info:

Location: Dallas, Texas

Role: Owner’s Representative

Owner: Texas Department of Transportation

Client: Brown & Gay Engineers, Inc.

Construction Cost: $845,795,945


  • Constructability Review
  • Design-Build Delivery
  • Frontage Road Design
  • Interstate Design
  • Quality Control and Assurance
  • Structural Design
  • Toll Facility Planning/Design


The I-35E corridor between I-635 and US 380 is one of Texas’s most congested roadways. To address the congestion and delays often experienced by drivers on this section of interstate, the Texas Department of Transportation (TxDOT) commissioned a design-build project for the construction of additional travel lanes and managed lanes. These improvements increased travel speeds through toll collection facilities and significantly improved highway capacity. This was the first phase in a proposed full reconstruction of the 28-mile corridor, providing one additional general purpose lane in each direction in Denton County, two reversible managed lanes from I-635 to FM 2181, and additional general purpose lanes and frontage roads across Lake Lewisville.

Lochner was a member of the general engineering consultant (GEC) team, working on behalf of TxDOT as the owner’s representative to oversee the project’s design activities. Lochner was responsible for the review of the project design plans—encompassing main lanes, managed lanes, frontage roads, structures, drainage, illumination, landscaping, and related facilities—to ensure that they met the requirements of the state, as set out in the design-build contract.

During the project’s proposal stage, TxDOT had provided a limited number of pavement cores at locations selected by the proposers. Additional cores extracted by the developer during the design phase appeared to indicate worse pavement conditions than had been shown by the cores provided by TxDOT. The developer submitted a corridor-wide white paper, including additional geotechnical data, which outlined the claim and the additional milling and overlay costs that would be incurred to provide a pavement structural capacity that complied with the contract’s technical provisions. If substantiated, the change order would have resulted in more than $50 million in unforeseen costs for the state. Lochner’s engineers reviewed the report and noted inconsistencies between the white paper, the pavement design reports, and the technical provisions. On the basis of Lochner’s analysis, TxDOT was able to diffuse the developer’s claim.