Bridges and Tunnels: Design, Construction, and Inspection

Connecting Communities With Our Leading-Edge, Innovative Structural Solutions

Across North America, from urban areas to rural suburbs, Gannett Fleming’s industry leaders bring extensive design, rehabilitation, inspection, and construction management experience to extend the life of aging infrastructure or create new structures.

We are on the cutting-edge of innovation, helping the industry transition from traditional 2D design to 3D model-centric design. In addition, our approach adopts Building Information Modeling (BIM) to horizontal infrastructure projects while keeping safety, sustainability, and resiliency top of mind. Leveraging these technologies allows you to visualize solutions and, therefore, make more informed decisions for your bridge, tunnel, or related structural projects.


Gannett Fleming’s experienced engineers help you find solutions that are within budget, context sensitive, and exceed conventional expectations. From multi-level interchanges to small stream crossings to complex railroad lines, our staff’s diversity enables us to deliver highly effective solutions across a broad spectrum of projects.

Gannett Fleming consistently receives recognition for our bridge leadership, ranking among the top 25 bridge design firms by Engineering News-Record (ENR).


We use ABC methods to compress schedules in a cost-effective manner while extending bridge longevity and reducing future costs. Our team’s vast experience ranges from final designs that incorporate innovative construction methods, like pre-fabricated materials and self-propelled modular transporters, to developing client-specific policies, guidelines, and procedures for ABC projects. We routinely employ ABC methods for both rail and roadway projects.

Accelerated bridge construction: a time-lapse video of U.S. Route Nos. 1&9 and 46 Bridge Over Jones Road Replacement, New Jersey


Bridge design has been a core strength of ours for over a century, ranging from concrete or steel highway bridges to commuter, freight, or high-speed rail bridges.

We’ve worked on high-profile, complex bridges, collaborating with clients to solve challenges such as:

  • Curved girder.
  • Fracture critical.
  • Spliced precast concrete.
  • Truss bridge.
  • Waterway crossing.

We bring unique results to your most challenging problems. Our leading-edge design solutions include:

  • Carbon Fiber Reinforced Polymers.
  • Cellular concrete fill over arches and substructures.
  • Folded steel plate girders.
  • Augercast bridge foundations.

We routinely provide efficient traditional structure design services for:

  • Culverts.
  • Noise barriers.
  • Retaining walls.
  • Sign support structures as part of our work.

We also consider ground conditions on our projects in areas such as ground support and soft ground.

Gannett Fleming’s experts have authored design and inspection manuals and specifications for the:

  • New Jersey Department of Transportation (NJDOT).
  • Pennsylvania Department of Transportation (PennDOT).
  • Arizona Department of Transportation (ADOT).
  • City of Phoenix.


Our National Bridge Inspection Standards (NBIS) certified team embraces safety and ingenuity when examining structures, often using drones to enhance inspection documentation and add efficiency in our access methods.

Using automated flight plans and drone data to stitch together photos into 3D models enables owners to have rich data to understand the real-time condition of their structural assets and identify any structurally deficient areas. Gannett Fleming also uses geographic information systems (GIS) to help clients better visualize, analyze, and communicate their bridge condition data. Additionally, our Society of Professional Rope Access Technicians (SPRAT) certified inspectors utilize industrial rope access techniques to minimize traffic impacts while performing hands-on inspections of complex bridges and hard-to-access critical components.


Gannett Fleming understands that timely and effective rehabilitation and preservation of existing bridges not only maintains public safety, but it does so in a cost-effective manner. We routinely provide inspection, design, and construction services for:

  • Bridge rehabilitation and replacements.
  • Substructure and superstructure strengthening.
  • Elimination of joints.
  • Coating repair and replacement.
  • Seismic retrofits.
  • All other typical timber, concrete, and steel rehabilitations.


Gannett Fleming has been a tunnel leader for more than 60 years, using this experience to help define the National Tunnel Inspection Standards (NTIS). Our thought leaders also:

  • Developed the original Federal Highway Administration (FHWA) national Tunnel Management System (TMS).
  • Authored portions of the Tunnel, Operations, Maintenance, Inspection, and Evaluation (TOMIE) Manual.
  • Established prioritization metrics for the National Cooperative Highway Research Program (NCHRP), which was distributed to all state departments of transportation.
  • FHWA and the American Association of State Highway and Transportation Officials (AASHTO).


Our top-notch team conducts inspections in accordance with NTIS, including the evaluation of mechanical and electrical systems. Bringing excellence to every project, we utilize 3D technology to:

  • Improve efficiency.
  • Provide recommendations to reduce maintenance.
  • Find ways to improve energy efficiency.


We provide comprehensive services for tunnel rehabilitations, including:

  • Structural repair.
  • New LED energy-efficient lighting.
  • Ventilation and life safety system design compliant with the National Fire Protection Association (NFPA).


Gannett Fleming helps clients develop and implement an asset management system, allowing you to prioritize your tunnel improvements. These have included work order management, condition databases, and integrated tunnel operations management.


Water infiltration is the primary cause of deterioration in tunnels. Our experienced staff works to develop solutions and employ waterproofing systems that eliminate the problem rather than treating the symptom.


Our tunnel team and security experts support agencies in preparing emergency ConOps documents and staging emergency response exercises, collaborating with local stakeholders and first responders.


  • 3D modeling.
  • Alternative delivery.
  • Asset management.
  • Construction management.
  • Emergency services.
  • Design.
  • Inspection.
  • Maintenance assessments.
  • Planning.
  • Policy and standards development.
  • Program management.
  • Rehabilitation and preservation.
  • Seismic analyses.
  • Utility improvements.


Are you looking for a reliable, collaborative partner? Do you have a planning, design, or construction challenge? We want to hear from you.

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Are you looking for a reliable, collaborative partner? Do you have a planning, design, or construction challenge? We want to hear from you.

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