Companion Guide to Video August 2012

www.fhwa.dot.gov/federal-aidessentials

As an integral part of our Nation’s transportation 

system, bridges connect us and ensure that 

businesses can move their goods seamlessly 

throughout the country. Bridge inspection and 

maintenance activities ensure that our bridges 

remain safe for all users. 

When agencies inspect and 

maintain their bridges, unsafe 

conditions can be addressed and 

the possibility of closure minimized.

A bridge failure in 1967 prompted Congress to 

pass legislation to ensure the safety of our 

Nation’s bridges and the traveling public. The 

National Bridge Inspection Standards, or NBIS, is 

the result of this legislation. The NBIS requires 

inspection of all publicly owned highway bridges 

greater than 20 feet in length.

While State departments of transportation, or 

State DOTs, are ultimately responsible for 

ensuring compliance with the NBIS, many States 

have delegated functions of this program to the 

bridge owner. 

Even if your State DOT performs the functions 

required by the NBIS, all bridge owners 

are responsible for understanding 

and complying with the NBIS 

requirements and any additional State 

requirements. 

The NBIS establishes minimum qualifications for 

inspection personnel, identifies which bridges to 

inspect, and defines the information to be 

collected and reported as part of the inspection 

process. 

In most cases, routine inspections are required at 

least every 24 months. 

Federal-aid Program Overview

Bridge Program

National Bridge Inspection Standards 

This program requires inspection of all publicly owned highway 

bridges longer than 20 feet
Federal-aid Essentials for Local Public Agencies

Some low-risk bridges may be inspected at 

intervals up to 48 months if prior approval is 

received from the Federal Highway 

Administration, or FHWA. 

In addition to routine inspections, bridge owners 

may have to perform other types of inspections.

This may include underwater inspections to verify 

the condition of bridge elements below the water 

surface and above the mud line; fracture critical 

inspections of steel bridge elements, whose 

failure may cause the bridge to collapse; damage 

inspections after a natural disaster or accident; 

and in-depth inspections.

Another important safety aspect of the NBIS is 

load rating. A load rating determines the safe 

load-carrying capacity of each bridge. After a 

bridge inspection, the load rating must be verified 

based upon the observed field conditions.

When it is determined that a bridge 

cannot safely carry State legal 

loads, the bridge must be loadrestricted or strengthened.

Bridge owners are responsible for properly 

strengthening, load restricting, or closing bridges 

when necessary.

Inspections typically will identify maintenance 

items, which may need to be addressed to keep 

the bridge in good working order. In some cases, 

an inspection may identify a critical finding. 

The NBIS defines a critical finding 

as a structural or safety-related 

deficiency that requires immediate 

follow-up inspection or action. 

The bridge owner must immediately address any 

identified critical finding because the finding could 

have a direct impact on public safety. 

Since the NBIS requires that each State have an 

established procedure to address and report 

critical findings, your State DOT can provide 

guidance on actions to take if a bridge inspection 

results in a critical finding. 

All bridges over water require a scour assessment.

This assessment determines the bridge’s 

vulnerability to erosion of material from around 

bridge supports to a depth that may cause 

instability or failure.

Development and implementation of a plan of 

action, or POA, is required for any bridge 

determined to be vulnerable to scour. 

The POA details the steps to take if the bridge 

experiences a flood event. 

Maintaining detailed records is an important 

component of a bridge inspection program. 
Federal-aid Essentials for Local Public Agencies

Bridge owners need to maintain a file for each 

bridge that includes load ratings, flood history, 

relevant maintenance data and inspection reports 

documenting findings from each inspection. 

The NBIS requires updates of bridge inspection 

data within 180 days of the inspection, but States 

may require this data in a shorter timeframe.

States report bridge inspection 

annually to FHWA, which stores the 

data in the National Bridge 

Inventory, or NBI. 

The NBI contains information on more than 

600,000 bridges nationwide. The FHWA uses the 

NBI data to track bridge conditions nationwide, 

monitor NBIS compliance, and prioritize funding 

decisions.

So you can see that as the bridge owner, 

understanding your role in meeting the NBIS 

requirements and performing the functions 

delegated to bridge owners by your State DOT is 

important. Working together with the State DOT 

will ensure that all of the requirements of the 

NBIS are met.

The bridge inspection program can 

save lives, minimize disruptions of 

vital services and prevent bigger 

problems before they develop.

Contact your State DOT for a detailed explanation 

of the bridge inspection program in your State and 

your responsibilities as a bridge owner.
Federal-aid Essentials for Local Public Agencies

The content of this 

document is not a 

substitute for 

information obtained 

from State departments 

of transportation, 

appropriate FHWA 

Division Offices, and 

applicable laws. 

Scenarios have been 

simplified for emphasis 

and do not necessarily 

reflect the actual range of 

requirements applicable 

to the scenario or this 

topic. This document

was created under 

contract number 

DTFH63-11-F-00026 by 

the Federal Highway 

Administration, U.S. 

Department of 

Transportation, and is 

offered to the public to 

heighten and focus 

awareness of Federal-aid 

requirements within the 

local public agencies 

community and 

reinforces the 

importance of these 

necessary policies, 

procedures, and 

practices.

This Companion Resource 

is the script content for 

the video production of 

the same name. 

Additional Resources

• Links to important NBIS issues 

http://www.fhwa.dot.gov/bridge/nbis.htm

• National standards for proper safety inspection and evaluation of all 

highway bridges 

http://www.ecfr.gov/cgi/t/text/textidx?c=ecfr&sid=370f47191998a86077876bcde37e49c3&rgn=div6&view=te

xt&node=23:1.0.1.7.28.3&idno=23

• The law establishing the NBIS

http://www.gpo.gov/fdsys/pkg/USCODE-2010-title23/pdf/USCODE-2010-

title23.pdf

• Information on all current bridge-related training courses 

http://www.nhi.fhwa.dot.gov/training/list_catalog.aspx?cat=&key=bridge&nu

m=&loc=&sta=%&typ=&ava=&str=&end=&tit=&lev=&drl=

• Guide to recording and coding data within the National Bridge Inventory 

database 

http://www.fhwa.dot.gov/bridge/mtguide.pdf