Questions and Answers on the Specification for the National Bridge Inventory
Except for any cited statutes or regulations, the contents of these Q&As do not have the force and effect of law and are not meant to bind the public in any way. These Q&As are intended only to provide information regarding existing requirements under the law or agency policies.
650.303 Applicability
Q303-1 Does the NBIS apply to railroad and pedestrian bridges not carrying highway traffic? (Updated 3/01/2023)
A303-1 No, the NBIS only applies to bridges that carry highways (23 CFR 650.303). Railroad and pedestrian structures that do not carry highways are not covered by the NBIS. However, owners are strongly encouraged to inspect non-highway bridges in the interest of public safety.
Q303-2 Does the NBIS apply to ancillary structures? (New 3/01/2023)
A303-2 No, the NBIS does not apply to inspection of sign support structures, high mast lighting, retaining walls, noise barrier structures or overhead traffic signs (23 CFR 650.303). However, owners are strongly encouraged to inspect ancillary structures in highway rights of way in the interest of public safety.
Q303-3 Does the NBIS apply to privately owned bridges? (Updated 3/01/2023)
A303-3 The NBIS only applies to private bridges where a public road directly carries the traveling public to the bridge, the public road continues on the other side, and the bridge is open to public travel (23 CFR 650.303). These private bridges are subject to the NBIS because of the seamless nature of transportation infrastructure across the Nation and the public expects a uniform level of safety on bridges open to public travel.
There are many privately owned bridges that are not subject to the NBIS. Some examples include, but are not limited to:
- A bridge located entirely on a private road or driveway.
- A privately owned bridge connected on one end to a public road and a private road or driveway immediately on the other end.
- A bridge in a gated subdivision or community.
- A bridge in a shopping center.
The Program Manager should consult with right of way and legal personnel as necessary for bridges in question to understand where public/private boundaries are to determine whether or not the NBIS applies.
Q303-4 Is a toll bridge subject to the NBIS? (New 3/01/2023)
A303-4 The vast majority of toll bridges are publicly owned, often by a publicly chartered toll authority, therefore they are subject to the NBIS. In the case of a privately owned toll bridge, the applicability of the NBIS is limited to where a public road directly carries the traveling public to the bridge, the public road continues on the other side, and the bridge is open to public travel (23 CFR 650.303).
Q303-5 Does the NBIS apply to bridges partially open to traffic while under construction? (Updated 3/01/2023)
A303-5 Yes, when a highway bridge or any portion of a highway bridge is open to public traffic, even if portions are still under construction, it is subject to the requirements of the NBIS (23 CFR 650.303).
To assist in clarifying FHWA's expectations for inspections, as based on the NBIS (23 CFR 650.303), included are a few example scenarios (list is not exhaustive):
- New bridge(s) – An initial inspection must be completed within 3 months for a bridge that opens to traffic. Completed new bridges not open to traffic are not subject to the NBIS since they are technically closed.
- Phased construction of a new bridge(s) – An initial inspection must be completed within 3 months for any portion of a bridge that opens to traffic. This includes partially built bridges, bridges being constructed through multiple phases or stages, and bridges being rehabilitated. Those portions of the bridge open to traffic and the bridge members/elements that constitute or carry vehicular live load path are to be inspected.
- Existing bridge being replaced with a new bridge – The existing bridge is to continue to be inspected per the NBIS as long as it or any portion remains in service as a highway bridge open to traffic. See example 2 above, for when any portion of the new bridge must be inspected.
- Rehabilitation of existing bridge – If the bridge is closed to all traffic during rehabilitation work, an initial inspection must be completed within 3 months of any portion of the bridge reopening to traffic. For an existing bridge that is being rehabilitated under phased construction, any portions open to traffic must continue to receive regularly scheduled inspections. See example 2 above, for when a portion of the bridge reopens to traffic and must be inspected.
FHWA encourages owners to complete the initial inspection of bridges under construction as soon as practical, preferably before the bridge or portion of the bridge opens to traffic. This practice allows for an inspection under more convenient circumstances for both the inspector and the travelling public. It may also assist in completing the final punch list for the bridge.
It may be prudent to include provisions in construction contracting documents that require the contractor to perform NBIS inspections that are due while a construction project is underway.
If during a construction project, an inspection cannot be conducted due to extenuating circumstances such as a hazardous project site, then those circumstances should be documented, and the Program Manager should contact FHWA in advance of when the inspection is due to determine what can be done to complete the inspection.
Q303-6 Does the NBIS apply to temporary bridges? (Updated 3/01/2023)
A303-6 Yes, when a temporary bridge is open to traffic, it is to be inspected per the NBIS to ensure public safety (23 CFR 650.303).