Appendix B 

National Bridge Inspection Standards 
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Subpart C 

National Bridge Inspection Standards 

Source: 69 FR 74436, Dec. 14, 2004, unless otherwise noted. 

§ 650.301 Purpose. 

This subpart sets the national standards for the proper safety inspection and evaluation of all 

highway bridges in accordance with 23 U.S.C. 151. 

§ 650.303 Applicability. 

The National Bridge Inspection Standards (NBIS) in this subpart apply to all structures defined as 

highway bridges located on all public roads. 

§ 650.305 Definitions. 

Terms used in this subpart are defined as follows: 

American Association of State Highway and Transportation Officials (AASHTO) Manual. 

“Manual for Condition Evaluation of Bridges,” second edition, published by the American 

Association of State Highway and Transportation Officials (incorporated by reference, see

§650.317). 

Bridge. A structure including supports erected over a depression or an obstruction, such as water, 

highway, or railway, and having a track or passageway for carrying traffic or other moving loads, 

and having an opening measured along the center of the roadway of more than 20 feet between 

undercopings of abutments or spring lines of arches, or extreme ends of openings for multiple 

boxes; it may also include multiple pipes, where the clear distance between openings is less than 

half of the smaller contiguous opening. 

Bridge inspection experience. Active participation in bridge inspections in accordance with the 

NBIS, in either a field inspection, supervisory, or management role. A combination of bridge 

design, bridge maintenance, bridge construction and bridge inspection experience, with the 

predominant amount in bridge inspection, is acceptable. 

Bridge inspection refresher training. The National Highway Institute “Bridge Inspection 

Refresher Training Course” 1

 or other State, local, or federally developed instruction aimed to 

improve quality of inspections, introduce new techniques, and maintain the consistency of the 

inspection program. 1

 The National Highway Institute training may be found at the following 

URL: http://www.nhi.fhwa.dot.gov./

Bridge Inspector's Reference Manual (BIRM). A comprehensive FHWA manual on programs, 

procedures and techniques for inspecting and evaluating a variety of in-service highway bridges. 

This manual may be purchased from the U.S. Government Printing Office, Washington, DC 

20402 and from National Technical Information Service, Springfield, Virginia 22161, and is 

available at the following URL: http://www.fhwa.dot.gov/bridge/bripub.htm. 

Complex bridge. Movable, suspension, cable stayed, and other bridges with unusual 

characteristics. 
Comprehensive bridge inspection training. Training that covers all aspects of bridge inspection 

and enables inspectors to relate conditions observed on a bridge to established criteria (see the 

Bridge Inspector's Reference Manual for the recommended material to be covered in a 

comprehensive training course). 

Critical finding. A structural or safety related deficiency that requires immediate follow-up 

inspection or action. 

Damage inspection. This is an unscheduled inspection to assess structural damage resulting from 

environmental factors or human actions. 

Fracture critical member (FCM). A steel member in tension, or with a tension element, whose 

failure would probably cause a portion of or the entire bridge to collapse. 

Fracture critical member inspection. A hands-on inspection of a fracture critical member or 

member components that may include visual and other nondestructive evaluation. 

Hands-on. Inspection within arms length of the component. Inspection uses visual techniques that 

may be supplemented by nondestructive testing. 

Highway. The term “highway” is defined in 23 U.S.C. 101(a)(11). 

In-depth inspection. A close-up, inspection of one or more members above or below the water 

level to identify any deficiencies not readily detectable using routine inspection procedures; 

hands-on inspection may be necessary at some locations. 

Initial inspection. The first inspection of a bridge as it becomes a part of the bridge file to provide 

all Structure Inventory and Appraisal (SI&A) data and other relevant data and to determine 

baseline structural conditions. 

Legal load. The maximum legal load for each vehicle configuration permitted by law for the State 

in which the bridge is located. 

Load rating. The determination of the live load carrying capacity of a bridge using bridge plans 

and supplemented by information gathered from a field inspection. 

National Institute for Certification in Engineering Technologies (NICET). The NICET provides 

nationally applicable voluntary certification programs covering several broad engineering 

technology fields and a number of specialized subfields. For information on the NICET program 

certification contact: National Institute for Certification in Engineering Technologies, 1420 King 

Street, Alexandria, VA 22314–2794. 

Operating rating. The maximum permissible live load to which the structure may be subjected 

for the load configuration used in the rating. 

Professional engineer (PE). An individual, who has fulfilled education and experience 

requirements and passed rigorous exams that, under State licensure laws, permits them to offer 

engineering services directly to the public. Engineering licensure laws vary from State to State, 

but, in general, to become a PE an individual must be a graduate of an engineering program 

accredited by the Accreditation Board for Engineering and Technology, pass the Fundamentals of 

Engineering exam, gain four years of experience working under a PE, and pass the Principles of 

Practice of Engineering exam. 
Program manager. The individual in charge of the program, that has been assigned or delegated 

the duties and responsibilities for bridge inspection, reporting, and inventory. The program 

manager provides overall leadership and is available to inspection team leaders to provide 

guidance. 

Public road. The term “public road” is defined in 23 U.S.C. 101(a)(27). 

Quality assurance (QA). The use of sampling and other measures to assure the adequacy of 

quality control procedures in order to verify or measure the quality level of the entire bridge 

inspection and load rating program. 

Quality control (QC). Procedures that are intended to maintain the quality of a bridge inspection 

and load rating at or above a specified level. 

Routine inspection. Regularly scheduled inspection consisting of observations and/or 

measurements needed to determine the physical and functional condition of the bridge, to identify 

any changes from initial or previously recorded conditions, and to ensure that the structure 

continues to satisfy present service requirements. 

Routine permit load. A live load, which has a gross weight, axle weight or distance between axles 

not conforming with State statutes for legally configured vehicles, authorized for unlimited trips 

over an extended period of time to move alongside other heavy vehicles on a regular basis. 

Scour. Erosion of streambed or bank material due to flowing water; often considered as being 

localized around piers and abutments of bridges. 

Scour critical bridge. A bridge with a foundation element that has been determined to be unstable 

for the observed or evaluated scour condition. 

Special inspection. An inspection scheduled at the discretion of the bridge owner, used to monitor 

a particular known or suspected deficiency. 

State transportation department. The term “State transportation department” is defined in 23 

U.S.C. 101(a)(34). 

Team leader. Individual in charge of an inspection team responsible for planning, preparing, and 

performing field inspection of the bridge. 

Underwater diver bridge inspection training. Training that covers all aspects of underwater 

bridge inspection and enables inspectors to relate the conditions of underwater bridge elements to 

established criteria (see the Bridge Inspector's Reference Manual section on underwater 

inspection for the recommended material to be covered in an underwater diver bridge inspection 

training course). 

Underwater inspection. Inspection of the underwater portion of a bridge substructure and the 

surrounding channel, which cannot be inspected visually at low water by wading or probing, 

generally requiring diving or other appropriate techniques. 

§ 650.307 Bridge inspection organization. 

a) Each State transportation department must inspect, or cause to be inspected, all highway 

bridges located on public roads that are fully or partially located within the State's 

boundaries, except for bridges that are owned by Federal agencies. 
b) Federal agencies must inspect, or cause to be inspected, all highway bridges located on public 

roads that are fully or partially located within the respective agency responsibility or 

jurisdiction. 

c) Each State transportation department or Federal agency must include a bridge inspection 

organization that is responsible for the following: 

1) Statewide or Federal agencywide bridge inspection policies and procedures, quality assurance 

and quality control, and preparation and maintenance of a bridge inventory. 

2) Bridge inspections, reports, load ratings and other requirements of these standards. 

d) Functions identified in paragraphs (c)(1) and (2) of this section may be delegated, but such 

delegation does not relieve the State transportation department or Federal agency of any of its 

responsibilities under this subpart. 

e) The State transportation department or Federal agency bridge inspection organization must 

have a program manager with the qualifications defined in §650.309(a), who has been 

delegated responsibility for paragraphs (c)(1) and (2) of this section. 

§ 650.309 Qualifications of personnel. 

a) A program manager must, at a minimum: 

1) Be a registered professional engineer, or have ten years bridge inspection experience; and 

2) Successfully complete a Federal Highway Administration (FHWA) approved comprehensive 

bridge inspection training course. 

b) There are five ways to qualify as a team leader. A team leader must, at a minimum: 

1) Have the qualifications specified in paragraph (a) of this section; or 

2) Have five years bridge inspection experience and have successfully completed an FHWA 

approved comprehensive bridge inspection training course; or 

3) Be certified as a Level III or IV Bridge Safety Inspector under the National Society of 

Professional Engineer's program for National Certification in Engineering Technologies 

(NICET) and have successfully completed an FHWA approved comprehensive bridge 

inspection training course, or 

4) Have all of the following: 

i) A bachelor's degree in engineering from a college or university accredited by or determined 

as substantially equivalent by the Accreditation Board for Engineering and Technology; 

ii) Successfully passed the National Council of Examiners for Engineering and Surveying 

Fundamentals of Engineering examination; 

iii) Two years of bridge inspection experience; and 

iv) Successfully completed an FHWA approved comprehensive bridge inspection training 

course, or 

5) Have all of the following: 

i) An associate's degree in engineering or engineering technology from a college or university 

accredited by or determined as substantially equivalent by the Accreditation Board for 

Engineering and Technology; 

ii) Four years of bridge inspection experience; and 
iii) Successfully completed an FHWA approved comprehensive bridge inspection training 

course. 

c) The individual charged with the overall responsibility for load rating bridges must be a 

registered professional engineer. 

d) An underwater bridge inspection diver must complete an FHWA approved comprehensive 

bridge inspection training course or other FHWA approved underwater diver bridge 

inspection training course. 

§ 650.311 Inspection frequency. 

a) Routine inspections. (1) Inspect each bridge at regular intervals not to exceed twenty-four 

months. 

2) Certain bridges require inspection at less than twenty-four-month intervals. Establish criteria 

to determine the level and frequency to which these bridges are inspected considering such 

factors as age, traffic characteristics, and known deficiencies. 

3) Certain bridges may be inspected at greater than twenty-four month intervals, not to exceed 

forty-eight-months, with written FHWA approval. This may be appropriate when past 

inspection findings and analysis justifies the increased inspection interval. 

b) Underwater inspections. (1) Inspect underwater structural elements at regular intervals not to 

exceed sixty months. 

2) Certain underwater structural elements require inspection at less than sixty-month intervals. 

Establish criteria to determine the level and frequency to which these members are inspected 

considering such factors as construction material, environment, age, scour characteristics, 

condition rating from past inspections and known deficiencies. 

3) Certain underwater structural elements may be inspected at greater than sixty-month 

intervals, not to exceed seventy-two months, with written FHWA approval. This may be 

appropriate when past inspection findings and analysis justifies the increased inspection 

interval. 

c) Fracture critical member (FCM) inspections. (1) Inspect FCMs at intervals not to exceed 

twenty-four months. 

2) Certain FCMs require inspection at less than twenty-four-month intervals. Establish criteria 

to determine the level and frequency to which these members are inspected considering such 

factors as age, traffic characteristics, and known deficiencies. 

d) Damage, in-depth, and special inspections. Establish criteria to determine the level and 

frequency of these inspections. 

§ 650.313 Inspection procedures. 

a) Inspect each bridge in accordance with the inspection procedures in the AASHTO Manual 

(incorporated by reference, see §650.317). 

b) Provide at least one team leader, who meets the minimum qualifications stated in §650.309, 

at the bridge at all times during each initial, routine, in-depth, fracture critical member and 

underwater inspection. 

c) Rate each bridge as to its safe load-carrying capacity in accordance with the AASHTO 

Manual (incorporated by reference, see §650.317). Post or restrict the bridge in accordance 

with the AASHTO Manual or in accordance with State law, when the maximum unrestricted 
legal loads or State routine permit loads exceed that allowed under the operating rating or 

equivalent rating factor. 

d) Prepare bridge files as described in the AASHTO Manual (incorporated by reference, see

§650.317). Maintain reports on the results of bridge inspections together with notations of 

any action taken to address the findings of such inspections. Maintain relevant maintenance 

and inspection data to allow assessment of current bridge condition. Record the findings and 

results of bridge inspections on standard State or Federal agency forms. 

e) Identify bridges with FCMs, bridges requiring underwater inspection, and bridges that are 

scour critical. 

1) Bridges with fracture critical members. In the inspection records, identify the location of 

FCMs and describe the FCM inspection frequency and procedures. Inspect FCMs according 

to these procedures. 

2) Bridges requiring underwater inspections. Identify the location of underwater elements and 

include a description of the underwater elements, the inspection frequency and the procedures 

in the inspection records for each bridge requiring underwater inspection. Inspect those 

elements requiring underwater inspections according to these procedures. 

3) Bridges that are scour critical. Prepare a plan of action to monitor known and potential 

deficiencies and to address critical findings. Monitor bridges that are scour critical in 

accordance with the plan. 

f) Complex bridges. Identify specialized inspection procedures, and additional inspector training 

and experience required to inspect complex bridges. Inspect complex bridges according to 

those procedures. 

g) Quality control and quality assurance. Assure systematic quality control (QC) and quality 

assurance (QA) procedures are used to maintain a high degree of accuracy and consistency in 

the inspection program. Include periodic field review of inspection teams, periodic bridge 

inspection refresher training for program managers and team leaders, and independent review 

of inspection reports and computations. 

h) Follow-up on critical findings. Establish a statewide or Federal agency wide procedure to 

assure that critical findings are addressed in a timely manner. Periodically notify the FHWA 

of the actions taken to resolve or monitor critical findings. 

§ 650.315 Inventory. 

a) Each State or Federal agency must prepare and maintain an inventory of all bridges subject to 

the NBIS. Certain Structure Inventory and Appraisal (SI&A) data must be collected and 

retained by the State or Federal agency for collection by the FHWA as requested. A 

tabulation of this data is contained in the SI&A sheet distributed by the FHWA as part of the 

“Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation's 

Bridges,” (December 1995) together with subsequent interim changes or the most recent 

version. Report the data using FHWA established procedures as outlined in the “Recording 

and Coding Guide for the Structure Inventory and Appraisal of the Nation's Bridges.” 

b) For routine, in-depth, fracture critical member, underwater, damage and special inspections 

enter the SI&A data into the State or Federal agency inventory within 90 days of the date of 

inspection for State or Federal agency bridges and within 180 days of the date of inspection 

for all other bridges. 

c) For existing bridge modifications that alter previously recorded data and for new bridges, 

enter the SI&A data into the State or Federal agency inventory within 90 days after the 
completion of the work for State or Federal agency bridges and within 180 days after the 

completion of the work for all other bridges. 

d) For changes in load restriction or closure status, enter the SI&A data into the State or Federal 

agency inventory within 90 days after the change in status of the structure for State or Federal 

agency bridges and within 180 days after the change in status of the structure for all other 

bridges. 

§ 650.317 Reference manuals. 

a) The materials listed in this subpart are incorporated by reference in the corresponding 

sections noted. These incorporations by reference were approved by the Director of the 

Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. These materials are 

incorporated as they exist on the date of the approval, and notice of any change in these 

documents will be published in the Federal Register. The materials are available for purchase 

at the address listed below, and are available for inspection at the National Archives and 

Records Administration (NARA). These materials may also be reviewed at the Department of 

Transportation Library, 400 Seventh Street, SW., Washington, DC, in Room 2200. For 

information on the availability of these materials at NARA call (202) 741–6030, or go to the 

following URL: 

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.

html In the event there is a conflict between the standards in this subpart and any of these 

materials, the standards in this subpart will apply. 

b) The following materials are available for purchase from the American Association of State 

Highway and Transportation Officials, Suite 249, 444 N. Capitol Street, NW., Washington, 

DC 20001. The materials may also be ordered via the AASHTO bookstore located at the 

following URL: http://www.aashto.org/aashto/home.nsf/FrontPage

1) The Manual for Condition Evaluation of Bridges, 1994, second edition, as amended by the 

1995, 1996, 1998, and 2000 interim revisions, AASHTO, incorporation by reference 

approved for §§650.305 and 650.313. 

2) 2001 Interim Revision to the Manual for Condition Evaluation of Bridges, AASHTO, 

incorporation by reference approved for §§650.305 and 650.313. 

3) 2003 Interim Revision to the Manual for Condition Evaluation of Bridges, AASHTO, 

incorporation by reference approved for §§650.305 and 650.313. 
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