I-35 Brazos River Bridges / Waco, Texas


  • 2016 National Steel Bridge Alliance Prize Bridge Awards Long Span Category
  • 2015 FICE Engineering Excellence Grand Award – Structures
  • 2015 ACEC Engineering Excellence Honor Award

Services Provided by FINLEY

  • Construction Engineering
  • Construction Analysis
  • Steel Girder Erection Design
  • Temporary Support Works Design
  • Three-dimensional Time-dependent Analysis (Used For Cable Analysis)
  • Construction Manual/Sequence
  • Stay Cable Stressing


  • Unique design will serve as a landmark for the region
  • First extradosed bridge in the United States using steel superstructure, which adds an extra complexity in maintaining the stay forces during construction

Start Date

July 2012

Completion date

June 2014



World Highways

In the News

Specifications & Details

Structural Engineer (240 KB)

LIFE SPAN October 2012 » Features » MODERN BRIDGE DESIGN Bridge design enters era of innovation as old structures need replacing and resources remain scarce. By Christina M. Zweig.

Reference Letter from Lane Construction (432 KB)

Roads & Bridges November 2012 (5 MB)

I-35 is a major north/south transportation artery in Texas used by locals, business travelers, and trucks carrying goods. The Texas Department of Transportation (TxDOT), City of Waco, and Baylor University wanted a signature bridge to match their local economic revitalization improvements and to add capacity to the roadways for the new 55,000 seat stadium at Baylor University. Two new 620’ long frontage road bridges with one-way traffic in each direction were built adjacent to I-35 over the Brazos River to relieve congestion for local traffic, increase mobility, and serve as a traffic detour should an accident occur on the interstate. Frontage road travelers no longer have to drive in the opposite direction from their destination as required by the existing turnarounds.

TxDOT selected an extradosed bridge which is a hybrid structure that combines elements of a steel box girder, reinforced concrete deck, and cable-supported superstructure. Although fairly common in other countries, extradosed bridges are rare in the United States. It is the first extradosed bridge in the United States using a steel composite superstructure, which adds an extra complexity in maintaining the stay forces during construction. The construction engineering loads are shared between girder and stays with the stays acting more as external post-tensioning rather than a vertical support. Steel beams work in conjunction with pylons anchored by shallow-angled cables, which carry between 20% and 30% of the bridge load.

FINLEY provided construction engineering analysis. Services included: steel girder erection design, temporary support works design, three-dimensional time-dependent analysis (used for cable analysis), construction manual/sequence & stay cable stressing.

The new bridges used an innovative design, which is highly aesthetic, durable, and cost-effective. This project was completed near budget and 4 ½  months ahead of schedule prior to Baylor University’s football season and opening of the new stadium. The new bridges now provide increased mobility & safety and are a regional landmark for the local community, traveling public, and over 100,000 tourists annually, who visit the Texas Ranger Hall of Fame and Museum in Waco.

Construction began in July 2012 and was completed 4 1/2 months ahead of schedule in June 2014.