Strengthening a Critical State Line Corridor: STV Delivers PS&E for IH-35 Reconstruction in Gainesville
At the northern gateway between Texas and Oklahoma, IH-35 serves as one of the region’s most important transportation links—carrying more than 50,000 vehicles a day and functioning as a primary freight route between two states. As infrastructure demands increased and aging facilities approached the end of their service life, the Texas Department of Transportation (TxDOT) initiated an ambitious effort to modernize an 8-mile stretch of the interstate near Gainesville, including one mile extending into Oklahoma.
To advance this priority corridor, TxDOT selected STV as the prime consultant to develop the complete Plans, Specifications, and Estimates (PS&E) for the reconstruction. With approximately $500 million in construction investment, the project is one of the largest undertaken within the Wichita Falls District and a rare interstate rebuild that crosses state lines.
A Comprehensive and Highly Coordinated Design Effort
The project encompasses a full redesign of interstate mainlanes, frontage roads, and ramps, along with substantial structural replacement needs. STV delivered roadway engineering, traffic control design, structural design for 10 bridges, and full survey services.
Across the six interchanges, the project team addressed a wide range of engineering challenges:
- A major stack-flip interchange requiring careful operational and geometric refinement
- An overpass crossing of BNSF Railway right-of-way with strict clearance, safety, and coordination requirements
- New and reconstructed overpasses meeting modern safety and mobility standards
- Complex hydraulic, environmental, and floodplain considerations associated with the Red River
At the state line, STV designed two new Red River bridges to improve safety, resiliency, and long-term serviceability for cross-state travel.
Interagency Coordination Across State, Federal, and Tribal Jurisdictions
Because the project extended into Oklahoma and affected both federal and tribal lands, its success depended on an exceptional level of interagency collaboration. STV led coordination with a broad group of stakeholders, including:
- Texas Department of Transportation (TxDOT)
- Oklahoma Department of Transportation (ODOT)
- Federal Highway Administration (FHWA)
- U.S. Army Corps of Engineers (Tulsa District)
- Federal Emergency Management Agency (FEMA)
- The City of Gainesville
- The Chickasaw Nation
- Multiple cities and counties throughout the region
Each discipline—roadway, structures, traffic control, hydraulic design, survey—navigated various regulatory requirements, technical review procedures, and agency standards. The cross-border nature of the work required consistent communication and a clear, structured review process to ensure design compatibility across jurisdictions.
Delivering Under Federal Grant Requirements
A portion of the project was funded through the INFRA (Infrastructure for Rebuilding America) program, which places significant emphasis on schedule performance and milestone adherence. The accelerated delivery timeline required rigorous planning, frequent internal design checkpoints, and structured coordination cycles with TxDOT, ODOT, and federal partners.
STV implemented design management tools, phased submittals, and advanced modeling workflows to maintain pace without compromising technical quality. The team’s ability to respond quickly to review comments, refine alternatives, and maintain alignment among agencies was essential to meeting federal grant expectations.
Adapting Design During Active Right-of-Way Acquisition
As PS&E development progressed, TxDOT introduced substantial schematic modifications—even as right-of-way (ROW) acquisition was already underway. To prevent delays, STV executed a strategic, parallel approach that included:
- Segmented 3D modeling to expedite ROW verification
- Targeted geometric refinements to minimize additional ROW impacts
- Rapid updates to ROW maps, parcels, and acquisition documents
- Close coordination between roadway, survey, and ROW teams to address changes in real time
This adaptive process allowed acquisition activities to continue without interrupting the design schedule or triggering unnecessary new property impacts.
A Modern Corridor Built for Regional Growth
When constructed, the Gainesville IH-35 improvements will expand the roadway to a six-lane interstate, reconstruct outdated interchanges, and replace critical river crossings to support long-term mobility between Texas and Oklahoma. The redesign enhances freight reliability, improves safety, and prepares the corridor for future population and economic growth on both sides of the Red River.
For TxDOT, ODOT, and their partners, the PS&E deliverables represent a coordinated, future-focused blueprint for a stronger interstate connection—one that balances state, federal, and tribal priorities while supporting the movement of people and goods across the region.
