Bridges & Structures

Data Submittal Validation Logic

Data validation is an important part of ensuring that the National Bridge Inventory (NBI) contains complete and accurate data. During the transition from the Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation’s Bridges (Coding Guide) format to the Specifications for the National Bridge Inventory (SNBI) format, data validation will be an iterative process. The use of temporary codes for the 2026 and 2027 submittals adds another layer of complexity. FHWA will continue to refine and update the data validation process as we work through the transition.

FHWA’s data validation process will include a combination of data verification checks prior to accepting data into the NBI. Data verification ensures quality and consistency for the following:

• Data “type” verification ensures that submitted data is the correct data type (alphanumeric, numeric, or date) for each field.
• Code value verification ensures that submitted data is from a valid list of values as defined in the SNBI.
• Format verification ensures that submitted data matches the format required by the SNBI.
• Uniqueness verification guards against duplicate records.
• Presence verification ensures that all mandatory fields are submitted.

Errors generated during the validation process generally fall into two categories:

• Critical Errors prevent individual bridge records from being processed and therefore prevent final acceptance of the file. A file containing critical errors will be returned for correction and resubmittal within 15 business days.
• General errors are true errors that are not considered critical but are nonetheless important and must be corrected prior to the next submittal. General errors include failure to report required items and items that are required when applicable.

TABLE 1. Validation logic used to complete the data verification described above. Items with critical errors are indicated in the table.

• Table 1. SNBI Data Verification (HTML)
• Table 1. SNBI Data Verification (Excel)

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TABLE 2. Safety Validation for Closed and Posted Bridges

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Tables 3 thru 5 below indicate whether an item requires reporting and which category of error may be generated if the item is not reported or is not a valid value.

• Items designated “Y” in the Data Must be Reported column fall into two categories:
  1. Required field that will generate a critical error if not reported.
  2. Must be reported because valid values include a value indicating the field is “not applicable.”
• Items designated “WA” in the Must be Reported column are only reported when applicable. Refer to the specification and commentary in the SNBI for applicability of specific data items.
• Items designated “N” in the Must be Reported column are designated as “optional” in the item commentary.
• The BORDER BRIDGE columns outline the reporting responsibilities for States that have bridges crossing their State borders:
• DESIGNATED LEAD STATE column:
• Y = item is required to be reported by the Designated Lead State.
• WA = item is required to be reported by the Designated Lead State when applicable.
• N – item is designated as optional in the item commentary.
• NEIGHBORING STATE column:
• Y = item is required to be reported by the Neighboring State.
• DNR = DO NOT REPORT ITEM.

TABLE 3. The items in this table apply to all bridges and have a one-to-one relationship with a bridge. Some of these items are reported only when applicable. Fatal and critical errors are indicated in the Error Type column.

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TABLE 4. Each bridge is required to have at least one of each of these data sets:

• Span Material Type – Items beginning with B.SP
• Substructure Material and Type – Items beginning with B.SB (Exception: These items are not reported when B.SP.01 Span Type is P01 or P02)
• Features – Items beginning with B.F
• Routes – Items beginning with B.RT
• Highways – Items beginning with B.H
• Inspection Events – Items beginning with B.IE
• Work Events – Items beginning with B.W
• These items have a many-to-one relationship with a bridge so there may be multiple sets of these data items submitted. Some of these items are reported only when applicable. Refer to the specification and commentary in the SNBI for applicability of specific data items.

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TABLE 5. Items in this table have a many-to-one relationship so there may be multiple sets of these data items submitted.

These items are reported only when applicable. Refer to the specification and commentary in the SNBI for applicability of specific data items. Items beginning with B.RR are required when the value for B.F.01 Feature Type begins with “R” (R##). Items beginning with B.N may be required when the value for B.F.01 Feature Type begins with “W” (W##) and depends on value for B.N.01 Navigable Waterway. Items beginning with B.E and B.CS are required when the value for B.H.03 NHS Designation is “Y.”

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