U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590

Skip to content
Facebook iconYouTube iconTwitter iconFlickr iconLinkedInInstagram

Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

This report is an archived publication and may contain dated technical, contact, and link information
Back to Publication List        
Publication Number:  FHWA-HRT-16-007    Date:  January 2016
Publication Number: FHWA-HRT-16-007
Date: January 2016


Long-Term Bridge Performance (LTBP) Program Protocols, Version 1

Chapter 4. LTBP Program Protocol Content


Each of the LTBP Program protocols is organized into the following sections to provide information related to the data collection method being described:

Data Collected: Includes the bridge characteristic, condition, or defect about which data are to be collected, if applicable.

Onsite Equipment and Personnel Requirements: Lists equipment to be used in the data collection. The requirements also include references to safety and personnel qualification requirements.

Methodology: Describes how tests are to be conducted for the purposes of the LTBP Program, with references to the American Association of State Highway and Transportation Officials (AASHTO) and/or the American Society of Testing and Materials (ASTM) specifications, as appropriate. The methodology also gives a detailed description of how to take measurements of defects.

Data Collection Table: Guides what data and how the data have to be reported, with a key defining fields and colors. See Row Color Key for further details.

Criteria for Data Validation: Provides methods for determining if the data being collected are valid; this can vary based on the type of data being collected and the method of data collection.

Commentary/Background: Includes the following, as appropriate:

References: Refers to certain overarching protocols to keep data collection consistent and may also include references to external sources, such as AASHTO, ASTM, or FHWA standards.

Unless it is necessary for LTBP Program research purposes, the protocols for visual, hands-on evaluation of bridge elements are consistent with the bridge inspection guidance in the latest version of FHWA’s Bridge Inspector Reference Manual (BIRM) dated 2012. Unless otherwise defined in the text of the protocols, the bridge terminology used in the LTBP Program protocols for visual inspection is consistent with the definitions in the glossary to BIRM 2012.


Each LTBP Program protocol contains a table describing the manner in which data are to be collected. Table 1 illustrates the format of the LTBP Program data collection tables. Table 2 defines the types of information contained in each column and the colors of each row.

Table 1. Sample LTBP Program Protocol Data Collection Table.

# Field Name Data Type Accuracy Unit Field Description Row Color
1 State Text State Code; e.g., Virginia = VA Green
2 NBI structure number Text Item 8, structure number; from NBI Coding Guide Green
3 Structure name Text Descriptive name for the bridge; e.g., Route 15 SB over I–66 Green
4 Protocol name Text Title of the protocol Green
5 Protocol version Text Month and year Month and year the protocol version was published; e.g., May 2015 Green
6 Personnel performing data collection activities Text First name(s) Last name(s) Green
7 Date data were collected Text Exact date mm/dd/yyyy Green
8 Location of defect: unique element identifier Text Record the unique element identifier of the element being evaluated for defects (for example, deck, abutmentA, girder 2B, etc.) Blue
9 Location of defect: element Text Describe the location of the defect on the bridge element (e.g., span number, lane number, shoulder, substructure unit, backwall of abutment, web of prestressed concrete girder, etc.) Blue
10 Type of defect Predefined list Crack
Other (specify in the comments)
11 Defect location 1 Number 1 in. For example: x-coordinate of a point on the defect Yellow
12 Defect location 2 Number 1 in. For example: y-coordinate of a point on the defect Yellow
13 Defect measurement 1 Number 0.5 in. For example: length of the defect Yellow
14 Defect measurement 1 Number 0.1 in. For example: width of the defect Yellow
15 Defect measurement 1 Number 0.1 in. For example: depth of the defect Yellow
16 Defect photos BLOB If defects are present, document typical defects with photos and/or sketches Yellow
17 Comments Text   Orange

Table 2. LTBP Program Protocol Data Collection Table Key.

Column Descriptions
# Sequential number of data item
Field Name Data field name
Data Type Type of data, such as text, number, predefined list, binary large object (BLOB), or PDF file
Accuracy Accuracy to which the data are recorded
Unit Unit in which a measurement is taken and recorded
Field Description Commentary on the data or list of items in a predefined list
Row Color Key
Green Data items only entered once for each protocol for each day the protocol is applied
Pink Logical breakdown of data by elements or defect types (not always used)
Blue Data identifying the element being evaluated or the type of defect being identified
Yellow LTBP data reported individually for each element or defect identified
Orange Comments on the data collection or data entered

In table 1, the green items serve to identify the bridge being evaluated, the protocol being followed, the person(s) conducting the tests and collecting the data, and the date of the evaluation (or data collection). The items shaded in blue provide information on the element of the bridge where the test is being performed and/or the distinct defect being measured and recorded. The items shaded in yellow are the data items being collected for each element/defect listed. During a typical assessment, on a bridge with multiples of the same element (such as a bridge with six girders), data items in yellow will be recorded in sequence and then the sequence repeated for each individual element or distinct defect until all elements have been evaluated under the relevant protocol. The orange row provides space for any relevant comments the researchers deem necessary to support the data being collected.


While each research team investigating LTBP Program bridges may use different tools to collect the data (such as collecting the data manually or via computer), all teams must provide data for import to the LTBP Program Bridge Portal in an identical format.



Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000
Turner-Fairbank Highway Research Center | 6300 Georgetown Pike | McLean, VA | 22101