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Tunnels

The nation’s highway and rail tunnels are aging and lack the life safety systems required by current standards. Operators of these tunnels face increasing regulatory demands with the National Tunnel Inspection Standards (NTIS) and State of Good Repair (SOGR) requirements. Gannett Fleming is an industry leader in the areas of tunnel inspection, evaluation, rehabilitation, and design. In addition, we’ve made significant contributions to the NTIS and bring this intimate knowledge to every project. 

Our Expertise

Inspections, Design, & Rehabilitations 
Known for our technical innovation and award-winning design, we have inspected, designed, and rehabilitated major highway and rail transit tunnels throughout the U.S.

We bring extensive structural and geotechnical experience to tunnel design projects, which have included the design of tunnels in both soft ground and in rock, using cut-and-cover, bored, and jacked techniques.

Our team is skilled in tunnel rehabilitation, particularly in evaluating water infiltration sources and applying the remediation and waterproofing that is crucial to developing a successful solution. Through life safety evaluations, we design upgrades to meet National Fire Protection Association (NFPA) standards, including new, state-of-the-art, energy-efficient ventilation and lighting systems and technologies.

Industry Leading Expertise
Our tunnel professionals lead the development of standards for tunnel inspection and maintenance. We developed the National Tunnel Management System for FHWA and FTA, authored portions of the Tunnel, Operations, Maintenance, Inspection, and Evaluation Manual (TOMIE), and established prioritization metrics for NCHRP. 

Tunnel Solutions

  • Inspection
  • Rehabilitation
  • Design
  • Life safety evaluations 
  • Highway tunnels
  • Transit tunnels
  • Pedestrian tunnels
  • Utility tunnels
  • Access shafts.

Our experienced team has earned a national reputation in tunnel inspection, rehabilitation, and design. As leaders in the development of national tunnel standards, we possess a comprehensive understanding of how to meet the toughest tunnel challenges, while meeting industry requirements.

Tunnel Services

Featured Services

  • Structural
  • Lighting design
  • Ventilation 
  • Electrical systems 
  • ITS
  • Supervisory Control and Data Acquisition System (SCADA)
  • Civil/Roadway 
  • Drainage
  • Geotechnical 
  • Geophysical testing
  • Ground dewatering and pretreatment
  • Security
  • GIS and system integration
  • Implementation of Tunnel Management Systems (TMS)
  • Maintenance of traffic
  • Traffic management.

Specialized Services

  • Life Safety Evaluations

    Life Safety Evaluations

    Our inspectors conduct evaluations to ensure your tunnel meets NFPA standards including life safety and emergency response, ventilation, and traffic control systems.


  • Big Savage Mountain Tunnel Rehabilitation-Gannett Fleming

    Water Infiltration Solutions

    Water infiltration is the number one contributor of deterioration in tunnels. Through leakage investigations, our experienced staff works to develop solutions and employ waterproofing systems that eliminate the problem rather than treating the symptom. We have evaluated and designed waterproofing systems that include liners, grouting, and traditional leak repair methods.
  • Lighting & Ventilation

    Lighting & Ventilation

    Tunnel ventilation and lighting systems are critical to the safety of the traveling public. Our team applies energy-efficient technologies and modern design practices to these critical systems. We provide rehabilitation design for tunnels to meet the requirements of NFPA for life safety and Illuminating Engineering Society of North America Recommended Practice for Tunnel Lighting RP-22.
  • Tunnel Asset Management

    Tunnel Asset Management

    We utilize a computerized Tunnel Management System (TMS) to store tunnel condition information and facilitate prioritization of repairs, as well as computerized maintenance management systems (CMMS) to proactively manage tunnel maintenance. With these technologies, we provide full capability to handle condition evaluation, maintenance, and repairs. Read more about Asset Management.
  • Rock Stabilization

    Rock Stabilization

    We specialize in the evaluation of rock stability and stabilization methods including rock bolting, grouting, and shotcrete, providing the expertise to respond to and prevent emergency situations. Read more about our Geotechnical capabilities.

Learn More About These Capabilities