Bridges & Structural
Having designed over one hundred bridges, our expansive design team is dedicated to improving the safety of structures through innovative 3D modeling and economic solutions to imrpove our communities and build our reputation as an industry leader.
Additionally, we can design the following:
• Retaining walls, all types
• Traffic Signals, Overhead and Cantilever
• Prestressed I-beams, slab beams, box beams, and TX-girders
• Hydraulic elements structures
SH 99 Grand Parkway: Segment H Bridges
Houston, Texas
Construction Cost
$1.2B
Bridges Construction Cost
$60M
Project Distance
37mi
As prime consultant for Segment H of the Grand Parkway, OTHON designed 13 new bridges and prepared cost estimates for all 52 structures along the corridor. These bridges incorporated the TxDOT Green Ribbon Program, with column heights ranging from 17 to 49 feet.
To optimize durability and efficiency, bent foundations used either dual 60-inch drilled shafts or single 96-inch shafts per column. The superstructures featured TX62 prestressed concrete girders with spans up to 138 feet—well beyond standard lengths. Using advanced PGSuper modeling, OTHON engineered longer spans without resorting to costly steel girders, delivering safe, high-performance structures with significant cost savings.
To optimize durability and efficiency, bent foundations used either dual 60-inch drilled shafts or single 96-inch shafts per column. The superstructures featured TX62 prestressed concrete girders with spans up to 138 feet—well beyond standard lengths. Using advanced PGSuper modeling, OTHON engineered longer spans without resorting to costly steel girders, delivering safe, high-performance structures with significant cost savings.
NTE Segment 3A South
Fort Worth, Texas
Construction Cost
$450M
Project Distance
4mi
OTHON served as Prime Design Consultant for the 3.9-mile reconstruction of IH 35W from north of IH 30 to NE 33rd Street, a high-volume corridor with over 144,000 vehicles per day. Delivered under a concurrent design-build schedule, the project included extensive bridge and structural work to modernize the corridor and maintain traffic flow throughout construction.
Our team provided full PS&E services, including the design of multiple bridge structures, culverts, retaining and noise walls, and ADA-compliant pedestrian facilities. Bridge layouts and structural design were coordinated with TxDOT and the contractor to meet standards and optimize constructability. OTHON also led traffic control planning, ITS and tolling design, and utility coordination to support safe, efficient delivery of this critical infrastructure.
Our team provided full PS&E services, including the design of multiple bridge structures, culverts, retaining and noise walls, and ADA-compliant pedestrian facilities. Bridge layouts and structural design were coordinated with TxDOT and the contractor to meet standards and optimize constructability. OTHON also led traffic control planning, ITS and tolling design, and utility coordination to support safe, efficient delivery of this critical infrastructure.
IH 35 NEX; Central San Antonio
San Antonio, Texas
Construction Cost
$1.5 B
Project Distance
20mi
As part of the I-35 NEX project in San Antonio, OTHON supported efforts to enhance safety, mobility, and congestion management along one of Texas’s most vital transportation corridors. A key component of the project includes the construction of elevated managed lanes and major bridge infrastructure.
Bridge improvements feature four new connector bridges at the I-35/I-410 North interchange and the reconstruction and widening of general-purpose lanes and bridges along Loop 1604 from Nacogdoches Road to east of Biltmore Lakes. These enhancements are designed to improve traffic flow, support regional growth, and ensure long-term resilience of the corridor’s critical crossings.
Bridge improvements feature four new connector bridges at the I-35/I-410 North interchange and the reconstruction and widening of general-purpose lanes and bridges along Loop 1604 from Nacogdoches Road to east of Biltmore Lakes. These enhancements are designed to improve traffic flow, support regional growth, and ensure long-term resilience of the corridor’s critical crossings.
NTE Segment 2W
Tarrant County, Texas
Construction Cost
$700M
OTHON played a key role in the NTE Segment 2W Project, a 7.5-mile urban freeway connecting Dallas and Fort Worth via SH 183. To accommodate projected traffic volumes exceeding 280,000 vehicles per day by 2030, the corridor was reconstructed to modern standards and expanded with high-occupancy/managed lanes.
The project featured 40 bridge structures, including 21 highway overpasses, 4 underpasses, 9 braided ramps, 5 direct connectors, and a pedestrian bridge. OTHON led schematic redesign efforts, transitioning managed lanes from elevated bridges to at-grade within the proposed ROW—streamlining construction and optimizing corridor integration.
The project featured 40 bridge structures, including 21 highway overpasses, 4 underpasses, 9 braided ramps, 5 direct connectors, and a pedestrian bridge. OTHON led schematic redesign efforts, transitioning managed lanes from elevated bridges to at-grade within the proposed ROW—streamlining construction and optimizing corridor integration.
