The National Bridge Inspection Standards (NBIS) were developed in 1971 and set national standards for proper safety inspection and evaluation of highway bridges. Inspections include routine and fracture critical inspections which are typically completed every two years as well as underwater inspections which are typically completed every five years. The NBIS also sets minimum standards for inspector certification which include, at a minimum, successful completion of a two week training course.

Hoyle, Tanner’s NBIS certified inspectors have performed bridge safety inspections following NBIS for all types of bridges from single span to complex, long-span bridges carrying interstate traffic or electrified railroad tracks and signature bridges over major interstates or waterways.

Bridge inspections are typically completed while the bridge is open to traffic with specialized access equipment. At times, due to weight restrictions, traffic volume or bridge geometry, it is not feasible to access the bridge with specialized equipment. For these situations, our staff includes Rope Access Technicians who are certified through the Society of Professional Rope Access Technicians (SPRAT). Using rope access techniques allows us to complete inspections minimizing disruption to traffic and have the added benefit of ‘hands-on’ inspection of portions of the bridge that would be difficult to access otherwise.

Our inspectors are supported by our professional engineers, designers, technicians, and administrative staff which allows us to schedule NBIS personnel on critical projects and still meet all the other project commitments. We have a proven record with bridge safety inspections as well as bridge and highway design projects.


  • NBIS Bridge Inspection
  • Load Rating
  • Emergency Response

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