Following its recognition as the 2025 Underground Construction Association (UCA) Project of the Year at RETC 2025, the Washington Metropolitan Area Transit Authority (WMATA) Yellow Line Tunnel Rehabilitation Project has been selected as one of three finalists for the International Tunnelling and Underground Space Association’s (ITA) Project of the Year award in the €100–€500 million category. It is the only project from the United States to be shortlisted among 51 submissions from 27 countries.

Led by Kiewit Infrastructure Co., the project involved the rehabilitation of two 50-year-old transit tunnels totaling approximately 3,000 feet in length. The work included structural upgrades to the segmental steel tunnel liners, corrosion protection, leak mitigation, and systems enhancements to extend the tunnels’ service life by at least another 50 years.

Gall Zeidler Consultants (GZ), as part of the GEC team, performed the initial detailed inspection of the steel lined tunnel, determining the extent of the remediation needed and providing recommendations. GZ then served as the EOR for sections of the rehabilitation project. 

The winners of the ITA Tunnelling Awards 2025 will be announced on October 1, 2025, in Belgrade, Serbia.

We wish WMATA and all project partners the very best in their pursuit of the ITA Tunnelling Award.

For more information on GZ’s project involvement, in particular with the initial inspection, please visit this page.

To view full press release please see this link.

Repairs to the steel-lined tunnels between Pentagon and L’Enfant Plaza Stations, both of which dated to original construction more than 40 years ago. (Image Courtesy of WMATA)