The Texas Department of Transportation (TxDOT) has chosen WSP, a leading engineering, environment and professional services consultancy, to provide engineering services for the 1.8 mile I-35 Capital Express Central Downtown (CapEx-C Downtown) Corridor reconstruction through downtown Austin.

WSP will provide plans, specifications and estimates (PS&E) for the 1.8 mile downtown segment, which is part of TxDOT’s expansive $4.5 billion, eight-mile I-35 Capital Express Central Project.

The project will include a specific focus on enhancing safety and mobility throughout the CapEx-C corridor through a variety of means, including:

• lowering the existing I-35 roadway and adding non-tolled high-occupancy vehicle (HOV) lanes in each direction,

• connecting downtown Austin communities by reconstructing east-west cross-street bridges,

• redesign of the CapMetro Red Line crossing at 4th Street to connect to the Austin Convention Center,

• adding pedestrian and bicycle paths, and

• designing the infrastructure support for the “caps” funded by the City of Austin and the University of Texas at Austin, which could include deck parks to serve neighboring communities.

WSP will design the traffic control phasing for both the downtown and University of Texas segments of the highway and coordinate efforts with various ongoing design and construction projects along the CapEx Corridor. CapEx-C is targeting completion in 2032.

“Capital Express Central Downtown is a signature project for TxDOT. It will enhance mobility in Austin and connect communities, improving safety and helping to alleviate congestion,” said Stephanie Messerli, senior vice president and Texas transportation leader at WSP. “The knowledge gained from WSP’s recent work on the adjacent Capital Express Central Lady Bird Lake PS&E will play a critical role in creating a successful plan for the Capital Express Central Downtown segment.”

The I-35 Capital Express Program project represents the first significant upgrade of the I-35 corridor since 1974. It includes three stand-alone projects — North, Central and South — and is part of TxDOT’s wider Mobility35 Program that covers nearly 80 miles of corridor through Williamson, Travis and Hays counties.