3.1-i 

Table of Contents

Section 3 ..................................................................................................................................................

Fundamentals of 

Bridge Inspection 

 3.1 Duties of the Bridge Inspection Team ................................................... 3.1.1 

 

 3.1.1 Introduction............................................................................... 3.1.1 

 

 3.1.2 Duties of the Bridge Inspection Team ...................................... 3.1.2 

 3.1.3 Planning the Inspection............................................................. 3.1.2 

 3.1.4 Preparing for Inspection............................................................ 3.1.2 

 Review Bridge Structure File ............................................. 3.1.2 

 Bridge Plans................................................................. 3.1.3 

 Previous Inspection Reports ........................................ 3.1.3 

 Maintenance and Repair Records ................................ 3.1.3 

 Rehabilitation Plans ..................................................... 3.1.3 

 Geotechnical Data........................................................ 3.1.3 

 Hydrologic Data........................................................... 3.1.4 

 Roadway Plans............................................................. 3.1.4 

 Additional Data............................................................ 3.1.4 

 Identify Components and Elements.................................... 3.1.4 

 Deck Element Numbering System............................... 3.1.5 

 Superstructure Element Numbering System................ 3.1.5 

 Substructure Element Numbering System ................... 3.1.5 

 Develop Inspection Sequence............................................. 3.1.6 

 Prepare and Organize Notes ............................................... 3.1.6 

 Traffic Control.................................................................... 3.1.7 

 Special Considerations ....................................................... 3.1.8 

 Time Requirements...................................................... 3.1.8 

 Peak Travel Times ....................................................... 3.1.8 

 Set-up Time.................................................................. 3.1.8 

 Access .......................................................................... 3.1.8 

 Weather........................................................................ 3.1.9 

 Safety Precautions........................................................ 3.1.9 

 Permits......................................................................... 3.1.9 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1-ii 

 Tools ............................................................................ 3.1.9 

 Subcontract Special Activities ..................................... 3.1.9 

 3.1.5 Performing the Inspection......................................................... 3.1.9 

 General Inspection Procedures......................................... 3.1.10 

 Approaches and Decks............................................... 3.1.10 

 Superstructures........................................................... 3.1.11 

 Bearings ..................................................................... 3.1.11 

 Substructures.............................................................. 3.1.11 

 Waterways.................................................................. 3.1.11 

 Inspection of Bridge Elements ......................................... 3.1.12 

 Timber Inspection ...................................................... 3.1.12 

 Concrete and Masonry Inspection.............................. 3.1.13 

 Steel and Iron Inspection ........................................... 3.1.13 

 3.1.6 Preparing the Report ............................................................... 3.1.13 

 3.1.7 Identifying Items for Repairs and Maintenance and Follow-up for . 

 Critical Findings...................................................................... 3.1.14 

3.1.8 Types of Bridge Inspection..................................................... 3.1.15 

 Initial (Inventory)....................................................... 3.1.15 

 Routine (Periodic)...................................................... 3.1.15 

 Damage ...................................................................... 3.1.15 

 In-Depth ..................................................................... 3.1.16

 Special (Interim) ........................................................ 3.1.16 
3.1.1 

Section 3 

Fundamentals of Bridge Inspection 

Topic 3.1 Duties of the Bridge Inspection 

Team 

3.1.1 

Introduction Bridge inspection is playing an increasingly important role in providing a safe 

infrastructure for the nation. As the nation’s bridges continue to age and 

deteriorate, an accurate and thorough assessment of each bridge’s condition is 

critical in maintaining a dependable highway system. 

There are five basic types of inspection: 

3⁄4 Initial (inventory) 

3⁄4 Routine (periodic) 

3⁄4 Damage 

3⁄4 In-depth 

3⁄4 Special (interim) 

These are discussed in Article 3.2 of the AASHTO Manual for Condition 

Evaluation of Bridges. Although this topic is organized for “in-depth” 

inspections, it applies to all inspection types. However, the amount of time and 

effort required for performing each duty will vary with the type of inspection 

performed. 

This section presents the duties of the bridge inspection team. It also describes 

how the inspection team can prepare for the inspection and some of the major 

inspection procedures. For some duties, the inspection program manager may be 

involved. 

3.1.2 

Duties of the Bridge 

Inspection Team 

There are five basic duties of the bridge inspection team: 

3⁄4 Planning the inspection 

3⁄4 Preparing for the inspection 

3⁄4 Performing the inspection 

3⁄4 Preparing the report 

3⁄4 Identifying items for repairs and maintenance 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.2 

The duties of the inspector are simply the tasks that must be performed in order to 

fulfill the responsibilities that come with the job. 

3.1.3 

Planning the 

Inspection 

In order to make the inspection orderly and systematic, the lead inspector should 

make plans in advance. Planning the inspection is necessary for an efficient, costeffective effort which will also result in a thorough and complete inspection. 

Basic activities include: 

3⁄4 Determination of the type of inspection 

3⁄4 Selection of the inspection team which must include a qualified team 

leader on site for all initial, routine, in-depth, fracture critical member or 

underwater inspections 

3⁄4 Evaluation of required activities (e.g., nondestructive testing and 

underwater inspection) 

3⁄4 Development of an inspection sequence 

3⁄4 Establishment of a schedule 

3.1.4 

Preparing for the 

Inspection 

Review Bridge Structure 

File

Preparation measures needed prior to the inspection include organizing the proper 

tools and equipment, reviewing the bridge structure files, and locating plans for the 

structure. The success of the on-site field inspection is largely dependent on the 

effort spent in preparing for the inspection. The major preparation activities 

include: 

3⁄4 Reviewing the bridge structure file 

3⁄4 Identifying the components and elements 

3⁄4 Developing an inspection sequence 

3⁄4 Preparing and organizing notes, forms, and sketches 

3⁄4 Arranging for traffic control 

3⁄4 Making arrangements for required methods of access 

3⁄4 Reviewing safety precautions 

3⁄4 Organizing tools and equipment 

3⁄4 Arranging for subcontract special activities 

3⁄4 Accounting for other special considerations 

The first step in preparing for a bridge inspection is to review the many available 

sources of information about the bridge, such as: 

3⁄4 “Design” and “As-built” bridge plans 

3⁄4 Previous inspection reports 

3⁄4 Maintenance and repair records 

3⁄4 Rehabilitation/Retrofit plans 

3⁄4 Geotechnical data 

3⁄4 Hydrologic data 

3⁄4 Roadway plans 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.3 

3⁄4 Utility plans 

3⁄4 Right-of-way plans 

 Bridge Plans

The bridge plans contain information about the bridge type, the number of spans, 

the use of simple or continuous spans, and the materials of construction (see 

Figure 3.1.1). They also contain information about the presence of composite 

action between the deck and girders, the use of framing action at the substructure 

members, and the kind of connection details used. The year of construction and 

the design loading are also usually contained in the bridge plans. 

 

Figure 3.1.1 Inspectors Reviewing Bridge Plans

 Previous Inspection Reports 

Previous inspection reports provide valuable information about the history of the 

bridge, documenting its condition in previous years. This information can be used 

to determine which components and elements of the bridge warrant special 

attention. It also allows the inspector to compare the current levels of deterioration 

with those noted during previous inspections to help determine the rate of 

deterioration. 

Maintenance and Repair Records

Maintenance and repair records allow the inspector to report all subsequent repairs 

during the inspection phase, noting the types, extent, and dates of the repairs. 

Rehabilitation Plans 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.4 

Rehabilitation plans show modifications and replacements performed on the 

structure. Just as with the design plans, “As-Built (or record) drawings are 

preferable. 

Geotechnical Data

Geotechnical data provides information about the foundation material below the 

structure. Sand, silt, or clay is more susceptible to settlement and scour problems 

than is rock. Therefore, structures founded on these materials should generally be 

given more attention with respect to foundation and scour issues than those 

founded on rock. 

Hydrologic Data

Hydrologic data provides information about the shape and location of the channel, 

the presence of protection devices, flood frequencies, and water elevations for 

various flood intervals. This information is needed for scour evaluation, expected 

flood flows, and water velocity. 

Roadway Plans

Roadway plans may provide some information if the structure plans are not 

available. 

Additional Data

Utility plans can be used to determine the types and numbers of utility 

attachments, and right-of-way plans can be used to determine the limits of the 

right-of-way, which can be a factor in determining access requirements. 

Identify Components and 

Elements 

Another important activity in preparing for the inspection is to establish the 

structure orientation, as well as a system for identifying the various components 

and elements of the bridge (see Figure 3.1.2). If drawings or previous inspection 

reports are available, the identification system used during the inspection should 

be the same as that used in these sources. 

Figure 3.1.2 Sample Bridge Numbering Sequence 

If no previous records are available, then the inspector should establish an 

identification system. The numbering system presented in this subtopic is one 

possible system, but some states may use a different numbering system. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.5 

 

The route direction can be determined based on mile markers or stationing, and 

this direction should be used to identify the beginning and the end of the bridge. 

Deck Element Numbering System

The deck element numbering system should include the deck sections (between 

construction joints), expansion joints, railing, parapets, and light standards. These 

elements should be numbered consecutively, from the beginning to the end of the 

bridge. 

Superstructure Element Numbering System

The superstructure element numbering system should include the spans, the 

beams, and, in the case of a truss, the panel points. The spans should be numbered 

consecutively, with Span 1 located at the beginning of the bridge. Multiple beams 

should be numbered consecutively from left to right facing in the route direction. 

Similar to spans, floorbeams should be numbered consecutively from the 

beginning of the bridge, but the first floorbeam should be labeled as Floorbeam 0. 

This will coordinate the floorbeam and the bay numbers such that a given 

floorbeam number will be located at the end of its corresponding bay. 

For trusses, the panel numbers should be numbered similarly to the floorbeams, 

beginning with Panel Point 0. Label both the upstream and downstream trusses. 

Points in the same vertical line have the same number. If there is no lower panel 

point in a particular vertical line, the numbers of the lower chord will skip a 

number (see Figure 3.1.3). Some design plans number to midspan on the truss and 

then number backwards to zero using prime numbers. However, this numbering 

system is not recommended for field inspection use since the prime designations in 

the field notes may be obscured by dirt. 

Figure 3.1.3 Sample Truss Numbering Scheme 

 Substructure Element Numbering System

The substructure element numbering system should include the abutments and the 

piers. Abutment 1 is located at the beginning of the bridge, and Abutment 2 is 

located at the end. The piers should be numbered consecutively, with Pier 1 

located closest to the beginning of the bridge (see Figure 3.1.2). Alternatively, all 

the substructure units may be numbered consecutively without noting abutments or 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.6 

piers. 

Develop Inspection 

Sequence 

An inspection normally begins with the deck and superstructure elements and 

proceeds to the substructure. However, there are many factors that must be 

considered when planning a sequence of inspection for a bridge, including: 

3⁄4 Type of bridge 

3⁄4 Condition of the bridge components 

3⁄4 Overall condition 

3⁄4 Inspection agency requirements 

3⁄4 Size and complexity of the bridge 

3⁄4 Traffic conditions 

3⁄4 Special procedures 

A sample inspection sequence for a bridge of average length and complexity is 

presented in Table 3.1.1. While developing an inspection sequence is important, it 

is of value only if following it ensures a complete and thorough inspection of the 

bridge.

1) Roadway Elements 4) Substructure Elements

 

3⁄4 Approach roadways 3⁄4 Abutments 

3⁄4 Traffic safety features 3⁄4 Skewbacks (arches) 

3⁄4 General alignment 3⁄4 Slope protection 

3⁄4 Approach alignment 3⁄4 Piers 

3⁄4 Deflections 3⁄4 Footings 

3⁄4 Settlement 3⁄4 Piles 

3⁄4 Curtain walls 

2) Deck Elements 

5) Channel and Waterway Elements 

3⁄4 Bridge deck surface 

3⁄4 Expansion joints 3⁄4 Channel profile and alignment 

3⁄4 Sidewalks and railings 3⁄4 Channel streambed 

3⁄4 Drainage 3⁄4 Channel embankment 

3⁄4 Signing 3⁄4 Channel embankment protection 

3⁄4 Electrical-lighting 3⁄4 Fenders 

3⁄4 Barriers, gates, and other traffic 

control devices 

3⁄4 Dolphins 

3⁄4 Hydraulic opening 

3⁄4 Bridge deck soffit 3⁄4 Water depth scales 

3⁄4 Navigational lights and aids 

3) Superstructure Elements 

 

3⁄4 Bearings 

3⁄4 Main supporting members 

3⁄4 Secondary members and bracings 

3⁄4 Utilities 

3⁄4 Anchorages 

 

Table 3.1.1 Sample Inspection Item List

Prepare and Organize 

Notes 

Preparing notes, forms, and sketches prior to the on-site inspection eliminates 

unnecessary work in the field. Copies of the agency’s standard inspection form 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.7 

should be obtained for use in recordkeeping and as a checklist to ensure that the 

condition of all elements is noted. 

Photocopy sketches from previous inspection reports so that defects previously 

documented can simply be updated. Preparing extra copies provides a contingency 

for sheets that may be lost or damaged in the field. 

If previous sketches are not available, then pre-made, generic sketches may be 

used for repetitive features or members. Possible applications of this timesaving 

procedure include deck sections, floor systems, bracing members, abutments, 

piers, and retaining walls. Numbered, pre-made sketches and forms can also 

provide a quality control check on work completed. 

Traffic Control Bridge inspection, like construction and maintenance activities on bridges, often 

presents motorists with unexpected and unusual situations (see Figure 3.1.4). 

Most state agencies have adopted the federal Manual on Uniform Traffic Control 

Devices for Streets and Highways (MUTCD). Some state and local jurisdictions, 

however, issue their own manuals. When working in an area exposed to traffic, 

the bridge inspector should check and follow the governing standards. These 

standards will prescribe the minimum procedures for a number of typical 

applications and the proper use of standard traffic control devices, such as cones, 

signs, and flashing arrow boards. 

Figure 3.1.4 Traffic Control Operation 

Principles and procedures, which enhance the safety of motorists and bridge 

inspectors in work areas, include the following: 

3⁄4 Traffic safety should be a high priority element on every bridge inspection 

project where the inspectors' activities are exposed to traffic or likely to 

affect normal traffic movements. 

3⁄4 Traffic should be routed through work areas with geometrics and traffic 

control devices comparable to those employed for other highway 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.8 

situations. 

3⁄4 Traffic movement should be inhibited as little as practicable. 

3⁄4 Approaching motorists should be guided in a clear and positive manner 

throughout the bridge inspection site. 

3⁄4 On long duration inspections, routine inspection of traffic control devices 

should be performed. 

3⁄4 All persons responsible for the performance of traffic control operations 

should be adequately trained. 

In addition, schedules may have to be adjusted to accommodate traffic control 

needs. For example, the number of lanes that can be closed at one time may 

require conducting the inspection operation with less than optimum efficiency. 

While it might be most efficient to inspect a floor system from left to right, traffic 

control may dictate working full length, a few beams at a time. 

Special Considerations Time Requirements

The inspection report or the bridge record file should state the amount of time 

required for the inspection. The inspection time requirements should be broken 

down into office preparation, travel time, field time, and report preparation. The 

overall condition of the bridge will play a major role in determining how long an 

inspection will take. Previous inspection reports provide an indication of the 

bridge's overall condition. It generally takes more time to inspect and document a 

deteriorated element (e.g., measuring, sketching, and photographing) than it does

to simply observe and document that an element is in good condition. 

Peak Travel Times

In populated areas, an inspection requiring traffic restrictions may be limited to 

certain hours of the day, such as 10:00 AM to 2:00 PM. Some days may be 

banned for inspection work altogether. Actual inspection time may be less than a 

40-hour work week in these situations, and schedules should be adjusted 

accordingly. 

Set-up Time 

Set-up time must be considered both before and during the inspection. For 

example, rigging efforts may require several days before the inspectors arrive on 

the site. Also, other equipment, such as compressors and cleaning equipment, may 

require daily set-up time. Adequate time should be provided in the schedule for 

set-up and take-down time requirements. The time to install and remove traffic 

control devices must also be considered. 

Access

Access requirements must also be considered when preparing for an inspection. 

Bridge members may be very similar to each other, but they may require different 

amounts of time to gain access to them. For example, it may take longer to 

maneuver a lift device to gain access to a floor system near utility lines than for 

one that is free of obstructions. On some structures, access hatches may need to be 

opened to gain access to a portion of the bridge. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.9 

Weather

Adverse weather conditions may not halt an inspection entirely, but may play a 

significant role in the inspection process. During adverse weather conditions, 

climbing should generally be avoided. There must be an increased awareness of 

safety hazards, and keeping notes dry can be difficult. During seasons of poor 

weather, a less aggressive schedule should be adopted than during the good 

weather months. 

Safety Precautions

While completing the inspection in a timely and efficient manner, the importance 

of taking safety precautions cannot be overlooked. The inspection team must 

follow the general guidelines for safe inspections. Confined space entry procedures 

must be in accordance with OSHA and the owners’ requirements. For climbing 

inspections, the three basic requirements for safe climbing must be followed. For 

additional information about safety precautions, refer to Topic 3.2.5. 

Permits

When inspecting a bridge owned by or crossing a railroad, an access permit 

generally must be obtained before proceeding with the field inspection. A permit 

must also be obtained when inspecting bridges passing over navigable waterways.

Environmental permits and permits to work around endangered species may be 

required for some bridges and bridge sites. 

Tools 

To perform a complete and accurate inspection, the proper tools and equipment 

must be used. Bridge location and type are two main factors in determining 

required tools and equipment. Refer to Topic 3.4 for a complete list of inspection 

tools and equipment. 

Subcontract Special Activities 

Consideration must be given to time requirements when special activities must be 

scheduled. These activities may include one or more of the following: 

3⁄4 Maintenance and protection of traffic (M.P.T.) 

3⁄4 Access, including rigging, inspection vehicle(s), or a combination there of 

3⁄4 Coordination with various railroads, including obtaining the services of 

railroad flagmen 

3.1.5 

Performing the 

Inspection 

This duty is the on-site work of accessing and examining bridge components and 

waterway, if present. 

Inspection procedures as presented in the NBIS should always be followed. 

Basic activities include: 

3⁄4 Visual examination of bridge components 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.10 

3⁄4 Physical examination of bridge components 

3⁄4 Evaluation of bridge components 

3⁄4 Examination and evaluation of the waterway beneath the structure, if any, 

 and approach roadway geometry 

General Inspection 

Procedures 

Duties associated with the inspection include maintaining the proper structure 

orientation and member numbering system, and following proper inspection 

procedures. 

The procedures used to inspect a bridge depend largely on the bridge type, the 

materials used, and the general condition of the bridge. Therefore, the inspector 

must be familiar with the basic inspection procedures for a wide variety of bridges.

A first step in the inspection procedure is to establish the orientation of the site and 

of the bridge. The orientation should include the compass directions, the direction 

of waterway flow, and the direction of the inventory route. Also record inspection 

team, air temperature, weather conditions, and time. 

After the site orientation has been established, the inspector is ready to begin the 

on-site inspection. The inspector must be careful and attentive to the work at 

hand, and no portion of the bridge should be overlooked. Those portions that are 

most critical to the structural integrity of the bridge should be given special 

attention. (Refer to Topic 8.1 for a description of fracture critical members in steel 

bridges.) 

The prudence used during the inspection must be combined with thorough and 

complete recordkeeping. Observations should be careful and attentive, and every 

defect should be recorded. A very careful inspection is worth no more than the 

records kept during that inspection. 

Numbers or letters should be crayoned or painted on the bridge to identify and 

code components and elements of the structure. The purpose of these marks is to 

keep track of the inspector’s location and to guard against overlooking any portion 

of the structure. 

The inspector should note the general approach roadway alignment, and sight 

along the railing and edge of the deck or girder to detect any misalignment or 

settlement. 

Approach Slabs and Decks

The inspector should check the approach pavement for unevenness, settlement, or 

roughness. Also check the condition of the shoulders, slopes, drainage, and 

approach guardrail. 

The deck and any sidewalks should be examined for various defects, noting size, 

type, extent, and location of each defect. The location should be referenced using 

the centerline or curb line, the span number, and the distance from a specific pier 

or joint. 

Examine the expansion joints for sufficient clearance and for adequate seal. 

Record the width of the joint opening at both curb lines, noting the air temperature 

and the general weather conditions at the time of the inspection. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.11 

Finally, check that safety features, signs, and lighting are present, and note their 

condition. 

Superstructures

The superstructure must be inspected thoroughly, since the failure of a main 

supporting member could result in the collapse of the bridge. The most common 

forms of main supporting members are: 

3⁄4 Beams and girders 

3⁄4 Floorbeams and stringers 

3⁄4 Trusses 

3⁄4 Catenary and suspender cables 

3⁄4 Eyebar chains 

3⁄4 Arch ribs 

3⁄4 Frames 

3⁄4 Pins and hanger plates 

Bearings 

The bearings must also be inspected thoroughly, since they provide the critical link 

between the superstructure and the substructure. Record the difference between 

the rocker tilt and a fixed reference line, noting the direction of tilt, the air or 

bearing material temperature, and the general weather conditions at the time of the 

inspection. 

Substructures

The substructure, which supports the superstructure, is made up of abutments, 

piers, and bents. If “as-built” plans are available, the dimensions of the 

substructure units should be compared with those presented on the plans. Since 

the primary method of bridge inspection is visual, all dirt, leaves, animal waste, 

and debris should be removed to allow close observation and evaluation. 

Substructure units should be checked for settlement by sighting along the 

superstructure and noting any tilting of vertical faces. In conjunction with the 

scour inspection of the waterway, the substructure units should be checked for 

undermining, noting both its extent and location. 

Waterways

Waterways are dynamic in nature, with their volume of flow and their path 

continually changing. Therefore, bridges passing over them must be carefully 

inspected for the effects of these changes. 

A record should be maintained of the channel profile and alignment, noting any 

meandering of the channel both upstream and downstream. Report any skew or 

improper location of the piers or abutments relative to the stream flow. 

Scour, the erosion of a riverbed area caused by stream flow, is the primary concern 

when evaluating the effects of waterways on bridges (see Figure 3.1.5). The 

existence and extent of scour must be determined using a grid system and noting 

the depth of the channel bottom at each grid point. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.12 

Figure 3.1.5 Inspection for Scour and Undermining 

Embankment erosion should be noted both upstream and downstream of the 

bridge, as should debris and excessive vegetation. Record their type, size, extent, 

and location. Note also the high water mark, referencing it to a fixed elevation 

such as the bottom of the superstructure. 

Inspection of Bridge 

Elements 

The inspector must be familiar with several general terms used to describe bridge 

defects: 

3⁄4 Corrosion – rusting 

3⁄4 Cracking - breaking away without separating into parts 

3⁄4 Splitting - separating into parts 

3⁄4 Connection slippage – relative movement of connected parts 

3⁄4 Overstress - deformation due to overload 

3⁄4 Collision damage - damage caused when a bridge is struck by vehicles or 

vessels 

Refer to Section 2 for a more detailed list and description of types and causes of 

deterioration for specific materials. As described in Section 2, each material is 

subject to unique defects. Therefore, the inspector should be familiar with the 

different inspection procedures used with each material. 

Timber Inspection

When inspecting timber structures, determine the extent and severity of decay, 

weathering and wear, being specific about dimensions, depths, and locations. 

Sound and probe the timber to detect hidden deterioration due to decay, insects, or 

marine borers. 

Note any large cracks, splits, or crushed areas. While collision or overload 

damage may cause these defects, the inspector should be factual, avoiding 

speculation as to the causes. Note any fire damage, recording the measurements of 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.13 

the remaining sound material. Document any exposed untreated portions of the 

wood, indicating the type, size, and location. 

Concrete and Masonry Inspection

When inspecting concrete structures, note all visible cracks, recording their type, 

width, length, and location. Any rust or efflorescence stains should also be 

recorded. Concrete scaling can occur on any exposed face of the concrete surface, 

and its area, location, depth, and general characteristics should be recorded. 

Inspect concrete surfaces for delamination or hollow zones, which are areas of 

incipient spalling, using a hammer or a chain drag. Delamination should be

carefully documented using sketches showing the location and pertinent 

dimensions. 

Unlike delamination, spalling is readily visible. Spalling should also be 

documented using sketches or photos, noting the depth of the spalling, the 

presence of exposed reinforcing steel, and any deterioration or section loss that 

may be present on the exposed bars. 

The examination of stone masonry and mortar is similar to that of concrete. The 

joints should be carefully inspected for cracks and other forms of mortar 

deterioration. Inspection techniques are generally the same as for concrete. (See 

Topic 2.2 for the examination of concrete.) 

Masonry arches or masonry-faced concrete arches should be checked for mortar 

cracks, vegetation, water seepage through cracks, loose or missing stones or 

blocks, weathering, and spalled or split blocks and stones. 

Steel and Iron Inspection

When inspecting steel or iron structures, determine the extent and severity of 

corrosion, carefully measuring the amount of cross section remaining. All cracks 

should be noted, recording their length, size, and location. Bent or damaged 

members should be documented, noting the type of damage and amount of 

deflection. 

Loose rivets or bolts can be detected by striking them with a hammer while 

holding a thumb on the opposite end of the rivet or bolt. Movement will be felt if 

it is loose. In addition, any missing rivets or bolts should also be noted. 

Note any frozen pins, hangers, or expansion devices. One indication of this is if 

the hangers or expansion rockers are inclined or rotated in a direction opposite to 

that expected for the current temperature. In cold weather, a rocker bearing should 

lean towards the fixed end of the bridge, while in hot weather, it should lean away 

from the fixed end. A locked bearing is generally caused by heavy rust on the 

bearing elements. 

For the inspector’s evaluation to be substantiated, all inspection findings must be 

documented or recorded. Documentation is referred to as the “condition remarks” 

on the inspection form or in the inspection report. 

3.1.6 

Preparing the 

Report 

Documentation is essential for any type of inspection. The inspector must gather 

enough information to ensure a comprehensive and complete report. Report 

preparation is a duty, which reflects the effort that the inspector puts into 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.14 

performing the inspection. Both must be comprehensive. The report is a record of 

both the bridge condition and the inspector's work. 

Basic activities in preparing the inspection report include: 

3⁄4 Completion of agency forms 

3⁄4 Objective written documentation of all inspection findings 

3⁄4 Providing photo references and sketches 

3⁄4 Objective evaluation of bridge components 

3⁄4 Recommendations and cost estimates 

3⁄4 Summary 

A sample bridge inspection report can be found in Appendix B of this manual. 

3.1.7 

Identifying Items 

for Repairs and 

Maintenance and 

Follow-up for 

Critical Findings 

The final basic duty is to identify items for repairs and maintenance. The inspector 

must identify such items to promote public safety and maximize longevity of the 

bridge. 

Most recommendations concerning repairs will be in the category of programmed 

repairs (i.e., repairs that will be incorporated into preprogrammed repair and 

maintenance schedules). Examples of maintenance activities include: flushing the 

deck, flushing the scuppers and down spouting, lubricating the bearings and 

painting the structure. 

The inspector must carefully consider the benefits to be derived from making 

repairs and the consequences if such repairs are not made. Also, the inspector 

should check the previous report recommendations to see what repairs and/or 

maintenance was identified and the priority of such items. If the repairs were to be 

completed before the next inspection, it is the responsibility of the inspector to 

note if the repairs have been completed and appear satisfactory. 

The updated NBIS regulations require a procedure for follow-up on critical 

findings. A statewide or Federal agency wide procedure must be established to 

assure that critical findings are addressed in a timely manner. The FHWA must be 

periodically notified of the actions taken to resolve or monitor critical findings. 

Critical findings are defined as a structural or safety related deficiency that 

requires immediate follow-up inspection or action. It is the responsibility of 

Bridge Owners to implement procedures for addressing critical deficiencies 

including: 

3⁄4 Immediate critical deficiency reporting steps 

3⁄4 Emergency notification of police and the public 

3⁄4 Rapid evaluation of the deficiencies 

3⁄4 Rapid implementation of corrective or protective actions 

3⁄4 A tracking system to ensure adequate follow-up 

3⁄4 Provisions for identifying other bridges with similar structural details for 

follow-up inspections 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.15 

3.1.8 

Types of Bridge 

Inspection 

The type of inspection may vary over the useful life of a bridge to reflect the 

intensity of inspection required at the time of inspection. The five types of 

inspections listed below will allow a Bridge Owner to establish appropriate 

inspection levels consistent with the inspection frequency and the type of structure 

and details. 

Initial (Inventory) An initial inspection is the first inspection of a bridge as it becomes a part of a 

bridge file, but the elements of an initial inspection may also apply when there has 

been a change in configuration of the structure (e.g., widening, lengthening, 

supplemental bents, etc.) or a change in bridge ownership. The initial inspection is 

a fully documented investigation and is accompanied by load capacity ratings.

First, this inspection provides all Structure Inventory and Appraisal (SI&A) data. 

Second, it provides baseline structural conditions and identification of existing 

problems. 

Routine (Periodic) Routine inspections are regularly scheduled inspections 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 

conditions. Inspection of underwater portions of the substructure is limited to 

observations during low-flow periods and/or probing for signs of undermining. 

The areas of the structure to be closely monitored are those determined by 

previous inspections and/or load rating calculations to be critical to load-carrying 

capacity. 

According to the NBIS, each bridge must be inspected at regular intervals not to 

exceed twenty-four months. However, certain bridges require inspection at less 

than the biennial cycle. Criteria must be established to determine inspection 

frequency and intensity based on such factors as age, traffic characteristics, and 

known deficiencies. Certain bridges may also be inspected at greater then the 

twenty-four month interval, not to exceed forty-eight months, with prior FHWA 

approval. This may be appropriate when past inspection findings and analysis 

justifies the increased inspection interval. 

Underwater structural elements are to be inspected at regular intervals not to 

exceed sixty months. However, certain underwater structural elements require 

inspection at less than the sixty month cycle. Criteria must be established to 

determine inspection frequency and intensity based on such factors as construction 

material, environment, age, scour characteristics, condition rating from past 

inspections and known deficiencies. Certain underwater structural elements may 

also be inspected at greater then the sixty month interval, not to exceed seventytwo months, with prior FHWA approval. This may be appropriate when past 

inspection findings and analysis justifies the increased inspection interval. 

Fracture critical members (FCMs) are to be inspected at regular intervals not to 

exceed twenty-four months. However, certain FCMs require inspection at less 

than the twenty-four month cycle. Criteria must be established to determine 

inspection frequency and intensity based on such factors as age, traffic 

characteristics, and known deficiencies. 

Damage A damage inspection is an unscheduled inspection to assess structural damage 

resulting from environmental factors or human actions. The scope of inspection 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.1: Duties of the Bridge Inspection Team 

3.1.16 

should be sufficient to determine the need for emergency load restrictions or 

closure of the bridge to traffic and to assess the level of effort necessary to effect a 

repair. A timely in-depth inspection may eliminate the need for this inspection. 

In-Depth An in-depth inspection is 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. When appropriate or necessary to fully ascertain the existence of or the 

extent of any deficiencies, nondestructive field tests may need to be performed. 

The inspection may include a load rating to assess the residual capacity of the 

member or members, depending on the extent of the deterioration or damage. For 

small bridges, the in-depth inspection should include all critical members of the 

structure. For large and complex structures, these inspections may be scheduled 

separately for defined segments of the bridge or for designated groups of elements, 

connections, or details. 

According to the NBIS, criteria must be established to determine the level and 

frequency of this type of inspection. 

Special (Interim) A special inspection is an inspection scheduled at the discretion of the Bridge 

Owner. It is used to monitor a particular known or suspected deficiency, such as 

foundation settlement or scour, fatigue damage, or the public’s use of a load posted 

bridge. Guidelines and procedures on what to observe and/or measure must be 

provided, and a timely process to interpret the field results should be in place. 

These inspections are not usually comprehensive enough to meet NBIS 

requirements for periodic inspections. 

According to the NBIS, criteria must be established to determine the level and 

frequency of this type of inspection. 
3.2-i

Table of Contents

Section 3 ..................................................................................................................................................

Fundamentals of 

Bridge Inspection 

 3.2 Safety Practices...................................................................................... 3.2.1 

 3.2.1 Key Concerns for Bridge Inspection Safety.............................. 3.2.1 

 3.2.2 Safety Responsibilities.............................................................. 3.2.2 

 3.2.3 Personal Protection ................................................................... 3.2.2 

 Proper Inspection Attire ..................................................... 3.2.2 

 Inspection Safety Equipment.............................................. 3.2.2 

 Hard Hat....................................................................... 3.2.3 

 Reflective Safety Vest.................................................. 3.2.4 

 Safety Goggles............................................................. 3.2.5 

 Gloves .......................................................................... 3.2.5 

 Life Jacket.................................................................... 3.2.6 

 Dust Mask / Respirator ................................................ 3.2.7 

 Safety Harness and Lanyard ........................................ 3.2.8 

 Boats ............................................................................ 3.2.9 

 3.2.4 Causes of Accidents.................................................................. 3.2.9 

 General Causes................................................................... 3.2.9 

 Specific Causes................................................................... 3.2.9 

 3.2.5 Safety Precautions..................................................................... 3.2.9 

 General ............................................................................... 3.2.9 

 Climbing Safety................................................................ 3.2.11 

 Organization............................................................... 3.2.11 

 Inspection Equipment ................................................ 3.2.12 

 Ladders.................................................................. 3.2.13 

 Scaffolding............................................................ 3.2.14 

 Timber Planks ....................................................... 3.2.14 

 Inspection Vehicles............................................... 3.2.14 

 Catwalks and Travelers......................................... 3.2.15 

 Rigging.................................................................. 3.2.16 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2-ii

 Mental Attitude .......................................................... 3.2.16 

 Confined Spaces Precautions ........................................... 3.2.17 

 Safety Concerns ......................................................... 3.2.17 

 Safety Procedures....................................................... 3.2.17 

 Culverts ............................................................................ 3.2.18 

 Inadequate Ventilation............................................... 3.2.18 

 Drowning ................................................................... 3.2.18 

 Toxic Chemicals ........................................................ 3.2.19 

 Animals...................................................................... 3.2.19 

 Quick Sand Conditions at the Outlet.......................... 3.2.19 
3.2.1

Topic 3.2 Safety Practices 

3.2.1 

Key Concerns for 

Bridge Inspection 

Safety 

While completing the inspection in a timely and efficient manner is important, 

safety is also a major concern in the field. Bridge inspection is inherently 

dangerous and therefore requires continual watchfulness on the part of each 

member of the inspection team. Attitude, alertness, and common sense are three 

important factors in maintaining safety. To reduce the possibility of accidents, 

bridge inspectors need to be concerned about safety. 

Five key motivations for bridge inspection safety: 

3⁄4 Injury and pain - Accidents can cause pain, suffering, and even death. 

Careless inspectors can severely injure or even kill themselves or others on 

the inspection team. Resulting pain and discomfort can hamper the 

inspector for the rest of their life. 

3⁄4 Family hardship - A worker’s family also suffers hardship when an 

accident occurs. Not only is there loss of income, but there is also the 

inability to participate in family activities. In the case of major disability, 

the burden of caring for the injured person falls on family members. 

3⁄4 Equipment damage - The repair or replacement of damaged equipment can 

be very costly. There is also a cost associated with the loss of time while 

the equipment is not available for use. 

3⁄4 Lost production - The employer loses revenues associated with the 

employee’s work, and also loses time and money spent on safety training 

and equipment. Additional inspectors must be trained to replace the 

injured worker. 

3⁄4 Medical expenses - Whether coverage is an employee benefit, personal 

insurance, or out of pocket, someone has to pay for medical expenses. 

Ultimately, the tax-paying public pays the bill for accidents through higher 

insurance premiums. 

Inspectors should constantly be aware of safety concerns. Spending the effort to 

be safe pays big dividends in avoided expenses and grief. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.2

3.2.2 

Safety 

Responsibilities 

The employer is responsible for providing a safe working environment, including: 

3⁄4 Clear safety regulations and guidelines 

3⁄4 Safety training 

3⁄4 Proper tools and equipment 

The supervisor is responsible for maintaining a safe working environment, 

including: 

3⁄4 Supervision of established job procedures 

3⁄4 Guidance in application of safety procedures 

3⁄4 Guidance in proper use of equipment 

3⁄4 Enforcement of safety regulations 

Bridge inspectors are ultimately responsible for their own safety. The bridge 

inspector's responsibilities include: 

3⁄4 Recognition of physical limitations – An inspector must be able to 

recognize his limitations and convey those limitations to his fellow 

inspectors. 

3⁄4 Knowledge of rules and requirements of job – An inspector should verify 

he understands a particular task and that he is qualified to perform that 

task. If a procedure appears to be unsafe, the inspector should question it 

and constructively try to develop a better way. 

3⁄4 Safety of fellow workers – Do not act in a manner that will endanger 

fellow inspectors. Warn co-workers if they are doing something unsafe. 

3⁄4 Reporting an accident – If there is an accident, it is essential to report it to 

a designated individual in your agency or company within the prescribed 

time frame, usually within 24 hours. Any injury must be promptly 

reported in order to assure coverage, if necessary, under workmen’s 

compensation or other insurance. 

3.2.3 

Personal Protection 

Proper Inspection Attire It is important to dress properly for the job. Field clothes should be properly sized 

for the individual, and they should be appropriate for the climate. For general 

inspection activities, the inspector should wear leather boots with traction lug 

soles. For climbing of bridge components, the inspector should wear boots with a 

steel shank (with non-slip soles without heavy lugs), as well as leather gloves. 

Wearing a tool pouch enables the inspector to carry tools and notes with hands free 

for climbing and other inspection activities. 

Inspection Safety 

Equipment 

Safety equipment is designed to prevent injury. However, the inspector must use 

the equipment correctly in order for it to provide protection. The following are 

some common pieces of safety equipment: 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.3

 Hard Hat 

A hard hat can prevent serious head injuries in two ways. First, it provides 

protection against falling objects. The bridge site environment during inspection 

activities is prone to falling objects. Main concerns are: 

3⁄4 Deteriorated portions of bridge components dislodged during inspection 

3⁄4 Equipment dropped by coworkers overhead 

3⁄4 Debris discarded by passing motorists 

Secondly, a hard hat protects the inspector’s head from accidental impact with 

bridge components. When inspections involve climbing or access equipment, the 

inspector is frequently dodging various configurations of superstructure elements. 

These superstructure elements can be sharp edged and are always unyielding. If 

the inspector makes a mistake in judgement during a maneuver and impacts the 

structure, a hard hat may prevent serious injury. 

During the inspection, the inspector never knows when protection will be needed. 

Therefore, a hard hat should be worn at all times. Also, if the inspector will be 

free climbing, it is a good practice to wear a chinstrap with the hard hat. 

Figure 3.2.1 Inspector Wearing A Hard Hat 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.4

 Reflective Safety Vest 

When performing activities near traffic, the inspector is required to wear a safety 

vest. The vest should conform to current OSHA standards. The combination of 

bright color and reflectivity makes the inspector more visible to passing motorists. 

Safety is improved when the motorist is aware of the inspector’s presence. 

Figure 3.2.2 Inspector Wearing A Reflective Safety Vest
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.5

 

Safety Goggles 

Eye protection is necessary when the inspector is exposed to flying particles. 

Glasses with shatterproof lenses are not adequate if side protection is not provided. 

It is also important to note that only single lens glasses should be worn when 

climbing (no bifocals). 

Eye protection should be worn during activities such as: 

3⁄4 Using a hammer 

3⁄4 Using a scraper or wire brush 

3⁄4 Grinding 

3⁄4 Shot or sand blasting 

3⁄4 Cutting 

3⁄4 Welding 

During welding activities, protection with appropriate lenses specifically designed 

for welding should be used. 

Gloves 

Although one may not immediately think of gloves as a piece of safety equipment, 

they can prove to be an important safety feature. Wearing gloves will protect the 

inspector’s hands from harmful effects of deteriorated members. In many 

inspections, structural members have been deteriorated to the point where the 

edges of the members have become razor sharp. These edges can cause severe 

cuts and lacerations to the inspector’s hands that may become infected. 

Figure 3.2.3 Inspector Wearing Safety Goggles and Gloves
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.6

Life Jacket 

A life jacket should always be worn when working over water or in a boat. If an 

accident occurs, good swimmers may drown if burdened with inspection 

equipment. Also, if knocked unconscious or injured due to a fall, a life jacket will 

keep the inspector afloat. A life jacket should also be worn when wearing hip or 

chest waders. If an inspector should slip or step in an area that is too deep, their 

waders can fill with water and drag them under, making swimming impossible. 

Figure 3.2.4 Inspector Wearing a Life Jacket
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.7

 

Dust Mask / Respirator 

A respirator or dust mask can protect the inspector from harmful airborne 

contaminants and pollutants. Agency or OSHA regulations should be consulted 

for approved types and appropriate usage. 

Conditions requiring a respirator include: 

3⁄4 Sand blasting 

3⁄4 Painting 

3⁄4 Exposure to dust from pigeon droppings (exposure to pigeon droppings 

may result in histoplasonosis, a potentially very serious illness) 

3⁄4 Work in closed or constricted areas

Figure 3.2.5 Inspector Wearing a Respirator 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.8

 

Safety Harness and Lanyard 

The safety harness and lanyard are the inspector’s lifeline in the event of a fall. 

Use this equipment as required by conditions. Make sure you satisfy agency and 

OSHA requirements. 

For example, some agencies require a safety belt or harness be worn in the 

following situations: 

3⁄4 At heights over 6.0 m (20 feet) 

3⁄4 Above water 

3⁄4 Above traffic 

Figure 3.2.6 Safety Harness with a Lanyard

To reduce the possibility of injury, the maximum lanyard length limits a fall to 1.8 

m (6 feet) per OSHA regulations. Further protection can be achieved using a 

shock absorber between the lanyard and the safety harness. The shock absorber 

reduces g-forces through the controlled extension of nylon webbing, which is prefolded and sewn together. Two lanyards are required and one lanyard should be 

tied off to a solid structural member or to a safety line rigged for this purpose at all 

times. The inspector should used the second lanyard to allow safe movement 

around obstacles connecting the second lanyard before disconnecting the first 

lanyard in order to safely move along the structure. 

Do not tie off to scaffolding or its supporting cable. One of the reasons for tying 

off is to limit your fall in case the rigging or scaffold fails. When working from a 

snooper or bucket truck, tie off to the structure if possible. Extreme caution must 

be exercised not to allow the equipment to be moved out from under someone tied 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.9

to the bridge. If the machine is being moved frequently, it is best to tie off to the 

bucket or boom. 

Boats 

When performing an inspection over water, it is required to have a manned boat in 

the water at all times. In the event of an accident in which someone were to fall 

into the water, the boat can rescue them quickly. This is especially important if the 

individual has been rendered unconscious. In addition, it can also be used to 

retrieve any equipment that may have been accidentally dropped by an inspector. 

3.2.4 

Causes of Accidents 

General Causes Accidents are usually caused by human error or equipment failure. Part of safety 

awareness is acknowledging this and planning ahead to minimize the effects of 

those errors or failures. 

Accidents caused by equipment failure can often be traced to inadequate or 

improper maintenance. Inspection, maintenance, and update of equipment can 

minimize failures. Accidents caused by people are usually caused by an error in 

judgment, thoughtlessness, or trying to take shortcuts. 

Specific Causes Specific causes of accidents include the following: 

3⁄4 Improper attitude – distraction, carelessness, worries over personal 

matters. 

3⁄4 Personal limitations – lack of knowledge or skill, exceeding physical 

capabilities. 

3⁄4 Physical impairment – previous injury, illness, side effect of medication, 

alcohol or drugs. 

3⁄4 Boredom – falling into an inattentive state while performing repetitive, 

routine tasks. 

3⁄4 Thoughtlessness - lack of safety awareness and not recognizing hazards. 

3⁄4 Shortcuts - sacrificing safety for time. 

3⁄4 Faulty equipment – damaged ladder rungs, worn rope, frayed cables or

access equipment not inspected regularly. 

3⁄4 Inappropriate or loose fitting clothing. 

3.2.5 

Safety Precautions Safety precautions can be divided into four main categories: General Precautions, 

Climbing Safety, Confined Spaces, and Culverts. 

General Some general guidelines for safe inspections are as follows: 

3⁄4 Keeping well rested and alert – Working conditions encountered during an 

inspection are varied and can change rapidly requiring the inspector be fit 

and attentive. 

3⁄4 Maintaining proper mental and physical condition – Inspection tasks 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.10

require a multitude of motor skills. To perform at acceptable levels, the 

inspector must be physically fit and free from mental distractions. 

3⁄4 Using proper tools – Do not try to use tools and equipment not suited for 

the job. 

3⁄4 Keeping work areas neat and uncluttered – Tools and equipment scattered 

carelessly about the work area present hazards that can result in injury. 

3⁄4 Establishing systematic procedures – Establish procedures early in the job

and utilize them so everyone knows what to expect of one another. 

3⁄4 Follow safety rules and regulations – Adhere to the safety rules and 

regulations established by the Occupational Safety and Health 

Administration (OSHA), the agency, and your employer. 

3⁄4 Use common sense and good judgment – Do not engage in horseplay, and 

do not take short cuts or foolish chances. 

3⁄4 Avoid use of intoxicants or drugs – Intoxicants impair judgement, 

reflexes, and coordination. 

3⁄4 Medication – Prescription and over-the-counter medications can cause 

drowsiness or other unwanted and potentially dangerous side effects. 

3⁄4 Electricity – This is a potential killer. All cables and wires should be 

assumed to be hot (live), even if they appear to be only telephone cables. 

The conditions encountered on many bridges are conducive to electric 

shock. These conditions include steel members, humidity, perspiration, 

and damp clothing. Transmission lines on a structure should be identified 

prior to the inspection. All power lines should be shut down. In rural 

areas, electric fences can be a hazard and should be avoided. Be aware that 

fiberglass posts eliminate the need for the distinctive porcelain insulation, 

which once identified electric fences. 

3⁄4 Assistance – Always work in pairs. An inspector should not take any 

action without someone else there to help in case of an accident. Always 

make sure someone else knows where you are. If someone seems to be 

missing, locate that person immediately. 

3⁄4 Inspection over water – A safety boat must be provided when working 

over water. It should be equipped with a life ring and have radio 

communication with the inspection crew. 

3⁄4 Waders – Caution should be used when wearing waders. If the inspector 

falls into a scour hole, the waders can fill with water, making swimming 

impossible. 

3⁄4 Inspection over traffic – It is best to avoid working above traffic. If it 

cannot be avoided, equipment, such as tools and clip boards, should be 

tied off. 

3⁄4 Entering dark areas – Use a flashlight to illuminate dark areas prior to 

entering as a precaution against falls, snakebites, and stinging insects. 

3⁄4 Homeless people – Caution should be exercised when approaching a 

bridge where homeless people are present. Explain to them an inspection 

of the bridge is taking place, and the inspection team will leave the site as 

soon as possible. Leave the bridge site immediately if there are any illegal 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.11

activities or perceived danger. 

Climbing Safety There are three primary areas of preparation necessary for a safe climbing 

inspection: 

1. Organization 

2. Inspection Access Equipment 

3. Mental attitude 

Figure 3.2.7 Inspection Involving Extensive Climbing

 

Organization 

Organization of the Inspection - A good inspection procedure incorporates a 

climbing strategy that minimizes climbing time. For example, beginning the day 

with an inspection of a truss span from one bent and finishing at the next bent by 

lunch time eliminates unproductive climbing across the span. 

The inspection procedure should have an inspection plan so the inspection team

knows where to go, what to do, and what tools are needed to perform the 

inspection. An organized inspection reduces the chance of the inspector falling or 

getting stuck in a position in which he is unable to get down. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.12

Weather conditions are a primary consideration when organizing a climbing 

inspection. Moderate temperatures and a sunny day are desirable. 

Rain conditions warrant postponement of steel bridge inspections, as wet steel is 

extremely slippery. 

After a rainy day, the inspector must be sure that boots are free of mud, and he 

must use extreme caution in areas where debris accumulation may cause a slippery 

surface. 

Traffic should not be obstructed during bad weather. Inspection of the top of 

concrete decks must also be avoided during or just after it rains. 

Figure 3.2.8 Inclement Weather Causing Slippery Bridge Members and Poor 

Visibility for Motorists 

 

Inspection Equipment 

The inspection team should be well equipped. 

Personal attire should be checked for suitability to the job: 

3⁄4 Clothing – proper for climbing activities and temperature. 

3⁄4 Jewelry – rings, bracelets, and necklaces should never be worn; in an 

accident, jewelry can become snagged and cause additional injury. 

3⁄4 Eyeglasses – only single lens glasses should be worn; bifocals should not 

be worn because split vision impairs the inspector’s ability to climb safely.

Inspection equipment should be checked for proper use and condition. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.13

Ladders 

Accidents involving ladders are the most common type of inspection-related 

accident. 

In order to use a ladder properly, these things are needed: 

3⁄4 Proper ladder length for the job. 

3⁄4 3:1 tilt with blocked and secured bottom. 

3⁄4 An assistant for ladders over 7.6 m (25 feet), and making sure the top is 

tied off. 

3⁄4 Inspecting the ladder, prior to use, for cracked or defective rungs and rails.

3⁄4 Correct climbing technique using both hands, facing the ladder, and 

keeping the inspector’s belt buckle over the rungs. 

3⁄4 Using a hand line to lift equipment or tools. 

Figure 3.2.9 Proper Use of Ladder
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.14

Scaffolding 

Scaffolding should be checked for the height and load capacity necessary to 

support the inspection team. 

Load tests can be performed on the ground with planned equipment and personnel. 

A daily inspection for cracks, loose connections, and buckled or weak areas should 

be performed prior to use. 

Timber Planks 

Single planks should never be used. Two or more planks securely cleated together 

should be used. Plank ends should be securely attached to their supports. All 

planks should be inspected for knots, splits, cracks, and deterioration prior to use. 

Inspection Vehicles 

Use of platform trucks, bucket trucks, and underbridge inspection vehicles may be 

necessary to access all elements during an inspection. Confirm that they are in 

safe operating condition. Such equipment must only be used when placed on a 

firm surface at a slope not exceeding the rated capacity of the equipment. 

Figure 3.2.10 Bucket Truck 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.15

Catwalks and Travelers 

Permanent inspection access devices are ideal. However, the inspector should be 

on guard for misalignment and deterioration of elements, such as flooring, handhold rods, and cables. 

Figure 3.2.11 Inspection Catwalk 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.16

Rigging 

The inspector should be familiar with proper rigging techniques. Support cables 

should be at least 13 mm (1/2 inch) in diameter. The working platform or "stage" 

should be at least 510 mm (20 inches) wide. A line or tie-off cable separate from 

the primary rigging should be used. 

Use common sense with regard to rigging. Do not blindly trust the people 

arranging the rigging. Mistakes by riggers can cause life threatening accidents. If 

a procedure is unsafe or doubtful, question it and get it changed if necessary. Do 

not rely on ropes or planks left on the bridge by prior work. They may be rotted or 

not properly attached. 

Figure 3.2.12 Inspection Rigging 

 

Mental Attitude 

The inspector must be mentally prepared to do a climbing inspection. A good 

safety attitude is of foremost importance. Three precautions that must be addressed 

are: 

3⁄4 Avoid emotional distress – Do not climb when emotionally upset. The 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.17

inspector who climbs must have complete control; otherwise the chances 

of falling increase. 

3⁄4 Awareness of surroundings – Always be aware of dangers associated with 

inspection location when climbing. Do not become so engrossed in the 

job as to step into mid-air. 

3⁄4 Realize limitations – An inspector must be confident the job can be 

performed safely. If there is a feature that cannot safely be inspected with 

the equipment available, do not inspect it. Highlight this fact in the notes 

so that appropriate equipment can be scheduled if necessary. Do not hide 

the fact that a particular bridge member was not inspected.

Confined Spaces 

Precautions 

Safety Concerns 

Inspection of box girder bridges, steel box pier caps, steel arch rings, arch ties, 

cellular concrete structures, and long culverts often includes confined spaces. 

Confined space entry is regulated by OSHA and requires proper training, 

equipment, and permitting. 

There are four major concerns when inspecting a confined space: 

3⁄4 Lack of oxygen – oxygen content must remain above 19% for the 

inspector to remain conscious 

3⁄4 Toxic gases – generally produced by work processes such as painting, 

burning, and welding or by operation of internal combustion engines 

3⁄4 Explosive gases – natural gas, methane, or gasoline vapors may be present 

naturally or due to leaks 

3⁄4 Lack of light – many confined spaces are totally dark (inspector cannot see 

any potential hazards such as depressions, drop-offs, or dangerous 

animals) 

Safety Procedures 

When a confined area must be inspected, the safety procedures prescribed by 

OSHA and any additional agency requirements must be used. The following is a 

general description of the basic requirements. Refer to OSHA for specifics. 

Pre-entry air tests: 

3⁄4 Test for oxygen with an approved oxygen testing device 

3⁄4 Test for other gases, such as carbon monoxide, hydrogen sulfide, methane, 

natural gas, and combustible vapors 

Mechanical ventilation: 

3⁄4 Pre-entry – Oxygen and gas levels must be acceptable for a minimum 

prescribed time prior to entry. 

3⁄4 During occupancy – Ventilation should be continuous regardless of 

activities. Test for oxygen and other gases at prescribed intervals during 

occupancy. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.18

Basic safety procedures: 

3⁄4 Avoid use of flammable liquids in the confined area. 

3⁄4 Position inspection vehicles away from the area entrance to avoid carbon 

monoxide fumes. 

3⁄4 Position gasoline powered generators "down-wind" of operations. 

3⁄4 Operations producing toxic gases should be performed "down-wind" of 

the operator and the inspection team. 

3⁄4 Carry approved rescue air-breathing apparatus. 

3⁄4 Use adequate lighting with an appropriate backup system and lifelines 

when entering dark areas, such as box girders and culverts. 

3⁄4 Inspection should be performed in pairs, with a third inspector remaining 

outside of dark or confined areas. 

Culverts There are several hazards that can be encountered when performing a culvert 

inspection. Being aware of these situations and exercising proper precautions will 

protect the inspector from these dangerous and potentially life threatening hazards. 

The following are some of the hazardous conditions an inspector may encounter. 

3⁄4 Inadequate Ventilation 

3⁄4 Drowning 

3⁄4 Toxic Chemicals 

3⁄4 Animals 

3⁄4 Quick Conditions 

3⁄4 Insufficient Number of Inspectors 

 Inadequate Ventilation

Culverts with inadequate ventilation can develop low oxygen levels or high 

concentrations of toxic and/or explosive gases. This is a big concern when one 

culvert end may be blocked or inspection is being performed on a long culvert. 

If air quality is suspect, tests should be made to determine the concentration of 

gases. Testing devices may be as simple as badges worn by inspectors that change 

colors when in the presence of a particular gas. Devices may also be sophisticated 

instruments that measure the concentration of several gases. 

Confined space entry requirements should be observed when inspecting a long 

culvert or any culvert with restricted ventilation. 

 Drowning

Extensive streambed scour may result in channel depressions. During periods of 

low flow the depth of water in these holes may be significantly greater than the 

remainder of the streambed. This could give the inspector the impression that 

wading is safe. It is advisable that the inspector use a probing rod to check water 

depth wherever he/she plans to walk. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.19

Storms may generate high flows in culverts very quickly. This creates a dangerous 

situation for the inspectors. It is not uncommon for culverts to carry peak flow 

long before a storm reaches the culvert site. Inspectors should be cautious 

whenever storms appear imminent. 

 Toxic Chemicals

Occasionally, stream flow may contain hazardous chemicals from any of a number 

of sources. Fires, explosions, and serious illness could result from the presence of 

such chemicals if appropriate precautions are not taken. 

 Animals

An accumulation of dirt or debris may provide a home for snakes, rodents, or other 

animals. These could provide a dangerous environment for the inspector. An 

inspector's ability to react to these hazards may be compromised by poor lighting,

limited access and inadequate room to move. Also, any dead animals present

create health hazards. 

 Quick Sand Conditions 

Quicksand conditions can occur in sandy streambeds, especially at the outlet end 

of the culvert. Inspectors should be aware of this and should proceed with caution 

in geographical areas known to have these problems. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.2: Safety Practices 

3.2.20

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3.3-i

Table of Contents

Section 3 ..................................................................................................................................................

Fundamentals of 

Bridge Inspection 

 3.3 Traffic Control ....................................................................................... 3.3.1 

 3.3.1 Introduction............................................................................... 3.3.1 

 3.3.2 Philosophy and Fundamental Principles................................... 3.3.1 

 Inform the Motorists ......................................................... 3.3.2 

 Control the Motorists........................................................ 3.3.2 

 Provide a Clearly Marked Path......................................... 3.3.2 

 3.3.3 Inspector Safety Practices ......................................................... 3.3.3 

 Work Zone ........................................................................ 3.3.3 

 Vehicles and Equipment ................................................... 3.3.4 

 Workers............................................................................. 3.3.4 

 3.3.4 Requirements of Traffic Control Devices................................. 3.3.5 

 3.3.5 Types of Traffic Control Devices ............................................. 3.3.6 

 Signs ................................................................................. 3.3.6 

 Channelizing Devices ....................................................... 3.3.7 

 Lighting............................................................................. 3.3.8 

 Flaggers........................................................................... 3.3.10 

 One-way Traffic Control ................................................ 3.3.13 

 Shadow Vehicles............................................................. 3.3.14 

 Police Assistance ............................................................ 3.3.14 

 3.3.6 Public Safety ........................................................................... 3.3.15 

 Training........................................................................... 3.3.15 

 Responsibility ................................................................. 3.3.15 
SECTION 3: Fundamentals of Bridge Inspection 

 TOPIC 3.3: Traffic Control 

3.3-ii

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3.3.1 

Topic 3.3 Traffic Control 

3.3.1 

Introduction Bridge inspection usually only requires traffic control procedures for a relatively 

short term closure (only a day or two). Long term closures for construction 

activity which use concrete barriers are not included in this topic. 

Figure 3.3.1 Traffic Control Operation 

Bridge inspection, like construction and maintenance activities on bridges, often 

presents motorists with unexpected and unusual situations. Most state agencies 

have adopted the federal Manual on Uniform Traffic Control Devices for Streets 

and Highways (MUTCD). Some states and local jurisdictions, however, issue their 

own standard manuals or drawings. 

When working in an area exposed to traffic, the bridge inspector should check and 

follow existing agency standards. These standards will prescribe the minimum 

procedures for a number of typical applications and the proper use of standard 

traffic control devices such as cones, signs, and flashing arrow-boards (see Figure 

3.3.1). Sometimes after initial installation, traffic control may need revision to 

provide adequate protection to motorists, pedestrians or inspectors. 

3.3.2 

Philosophy and 

Fundamental 

Principles 

All traffic control devices used on street and highway construction or maintenance 

work should conform to the applicable specifications of the MUTCD and the 

agency. 

Inspection time should be minimized to reduce exposure to potential hazards 

without compromising the thoroughness of the inspection. Principles and 

procedures which have been shown to enhance the safety of motorists, pedestrians, 

and bridge inspection in the vicinity of work areas include the following: 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.2

Inform the Motorists Traffic safety in work zones should be an integral and high priority element of 

every inspection project, from the planning stage to performance of the inspection. 

The safety of the motorist, pedestrian, and worker must be kept in mind at all 

times. 

The basic safety principles governing the design of traffic control for roadways 

and roadsides should also govern the design of inspection sites. The goal should 

be to route traffic through such areas with geometrics and traffic control devices 

comparable to those for normal highway situations. Notice of work site locations 

and guidance through these sites must be clearly communicated to the driver. 

A traffic control plan, in detail appropriate to the complexity of the work project, 

should be prepared and understood by all responsible parties before the site is 

occupied. Any changes in the traffic control plan should be approved by an 

official trained in safe traffic control practices. 

Control The Motorists Traffic movement should be inhibited as little as practical. Traffic control in work 

sites should be designed on the assumption that motorists will only reduce their 

speeds if they clearly perceive a need to do so. Reduced speed zoning should be 

avoided as much as practical. 

The objective is a traffic control plan that uses a variety of traffic control measures 

and devices in whatever combination necessary to assure smooth, safe vehicular 

movement past the work area and at the same time provide safety for the 

equipment and the workers on the job. Frequent and abrupt changes in geometrics, 

such as lane narrowing, dropped lanes, or main roadway transitions that require 

rapid maneuvers, should be avoided. 

Provisions should be made for the safe operation of work vehicles, particularly on 

high speed, high volume roadways. This includes the use of roof mounted flashing 

lights or flashers when entering or leaving the work zone. This also includes 

considering the number of lanes that can be closed at one time for an operation. 

While it might be most cost efficient to inspect a floor system from left to right, 

traffic control may dictate working full length, a few beams at a time. 

Provide a Clearly 

Marked Path 

A good traffic control plan provides safe and efficient movement of motorists and 

pedestrians and the protection of bridge inspectors at work areas. 

Adequate warning, delineation, and channelization should be provided to assure 

the motorist positive guidance in advance of and through the work area. Proper 

signing and other devices which are effective under varying conditions of daylight 

and weather must be used. 

The maintenance of roadside safety requires constant attention during the life of 

the work because of the potential increase in hazards. All traffic control devices 

should be removed immediately when no longer needed. 

To accommodate run-off-the-road incidents, disabled vehicles or other emergency 

situations, it is desirable to provide an unencumbered roadside recovery area that is 

as wide as practical. 

Channelization of traffic should be accomplished by the use of signing, cones, 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.3

barricades, and other lightweight devices which will yield when hit by errant 

vehicles. 

Whenever practical, equipment and materials should be stored in such a manner as 

not to be vulnerable to run-off-the-road vehicle impact. When safe storage is not 

available, adequate attenuation devices should be provided. 

3.3.3 

Inspector Safety 

Practices 

Work Zone Traffic represents as great, or even greater, threat to the inspector’s safety than 

climbing high bridges. The work zone is intended to be a safe haven from traffic 

so the inspectors can concentrate on doing their jobs. 

As such, the work zone needs to be clearly marked so as to guide the motorist 

around it and, insofar as possible, prevent errant vehicles from entering (see Figure 

3.3.2). The work zone should be as compact as possible to minimize traffic 

disruption, but must be wide enough and long enough to permit access to the area 

to be inspected and allow for safe movement of workers and equipment. The end 

of the work zone should be clearly signed as a courtesy to the motorist. 

Figure 3.3.2 Work Zone
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.4

Vehicles and Equipment Inspection vehicles and equipment need to be made visible to the motorists with 

flashing marker lights or arrow boards as appropriate (see Figure 3.3.3). 

Vehicles entering and exiting the work zone should use a roof mounted flashing 

light or flashers to distinguish themselves from other motorists. Also, all vehicles 

should use extreme caution when moving in and out of the work zone. Allow 

traffic ample time to react to the vehicle's movements. 

Figure 3.3.3 Inspection Vehicles with Flashing Light

Workers Individuals in a work zone must wear approved safety vests and hard hats for 

visibility and identification. They also help make the inspector look “official” to 

the public. The inspectors should also stay within the work zone for their own 

safety.
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.5

3.3.4 

Requirements of 

Traffic Control 

Devices 

Each bridge inspection project is different and has traffic concerns that are unique 

to that location. Selection of the proper traffic control device's for each location is 

dependent upon many factors. Though there are several different types of traffic 

control devises, there are some basic requirements for efficient traffic control 

devices: 

1. Traffic control devices must be visible and attention getting. 

3⁄4 Bright colors make devices easier to see for motorists. 

3⁄4 All signs must be legible and color distinguishable at night as well 

as during the day. Nighttime sign visibility is provided through 

retroreflectivity, which is accomplished by spherical glass beads 

or prismatic reflectors in the sign material. 

3⁄4 New sign messages such as “Slow Down. My Daddy Works 

Here” and “Give Us A Brake. Slow Down” cause the driver to 

think on a more personal level. 

2. Traffic control devices must give clear direction. 

3. Traffic control devices must command respect. They should be official 

(MUTCD). 

4. Traffic control devices must elicit the proper response at the proper time. 

3⁄4 The decision process includes the classical chain of sensing, 

perceiving, analyzing, deciding, and responding. 

3⁄4 The average perception-reaction time of a driver is 2.5 seconds. 

At 100 km/hr (60 mph), the 2.5 seconds translates to 67 m (220 

feet). Additional time and distance is required for a specific 

action taken such as “hitting the brakes”. 

3⁄4 Traffic control must accommodate a wide range of vehicles (from 

small compact cars to large combination tractor-trailers) and 

driver skills, which may be impaired by alcohol, drugs, 

drowsiness, or use of cellular telephones. 

All of these requirements for traffic control devices have been factored into the 

various agencies’ guidelines for work area traffic control. These guidelines 

represent efforts by trained people. Do not change traffic patterns without 

consulting agency standards or traffic control personnel. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.6

3.3.5 

Types of Traffic 

Control Devices 

Signs Examples of traffic control signs include the following: 

3⁄4 Regulatory - "Speed Limit 40 mph", "DO NOT PASS", may require 

special authority (see Figure 3.3.4) 

3⁄4 Warning - "Bridge Inspection", "Work Area Ahead", "Slow" (see Figure 

3.3.5) 

3⁄4 Guide Signs - Directional and destination signs; not used for bridge 

inspection traffic control unless a detour is established 

3⁄4 Changeable Message Signs – Can display more than one message 

Figure 3.3.4 Work Area Speed Limit Sign (Regulatory) 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.7

Figure 3.3.5 Traffic Control Sign (Warning) 

Channelizing Devices The functions of channelizing devices are to warn and alert drivers of hazards 

created by construction or maintenance activities in or near the traveled way and to 

guide and direct drivers safely past the hazards. 

Devices used for channelization should provide a smooth and gradual transition in 

moving traffic from one lane to another, onto a bypass or detour, or in reducing the 

width of the traveled way. They should be constructed so as not to inflict any 

undue damage to a vehicle that inadvertently strikes them. 

Channelizing devices are elements in a total system of traffic control devices for 

use in highway construction and maintenance operations. These elements should 

be preceded by a subsystem of warning devices that are adequate in size, number, 

and placement for the type of highway on which the work is to take place. 

Typical channelizing devices include the following: 

3⁄4 Cones (see Figure 3.3.6) 

3⁄4 Drums (see Figure 3.3.7) 

3⁄4 Wands 

3⁄4 Vertical panels 

3⁄4 Portable concrete barrier sections (these are seldom applicable to bridge 

inspection due to the short duration of the work)
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.8

Figure 3.3.6 Traffic Control Cones 

Figure 3.3.7 Traffic Control Drums 

Lighting Another type of control device is lighting. Examples of lighting include the 

following: 

3⁄4 Flashers - attached to signs or other devices to attract attention or for night 

visibility 

3⁄4 Arrowboards - for lane control (see Figure 3.3.8) 

3⁄4 Floodlights - to illuminate the work area at night and/or to assist motorists 

in negotiating a restricted area. Floodlights should only be required for 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.9

bridge inspection in emergencies or in extremely high traffic volume areas 

where lane restrictions are only feasible at night. They should be aimed so 

that a driver’s vision is not impaired.

3⁄4 Message boards – for lane control. Message boards can be programmed 

remotely using a cellular phone (see Figure 3.3.9)

Figure 3.3.8 Arrowboard 

Figure 3.3.9 Message Board 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.10

Flaggers A number of hand signalizing devices, such as STOP/SLOW paddles, lights, and 

red flags, are used to control traffic through work zones. The sign paddle bearing 

the clear messages "STOP" or "SLOW" provides motorists with more positive 

guidance than flags and is generally the primary hand signaling device. If 

permitted by the agency, flag use should be limited to emergency situations and at 

spot locations that can best be controlled by a single flagger. 

Since flaggers are responsible for human safety and make the greatest number of 

public contacts of all construction personnel, it is important that qualified 

personnel be selected. A flagger should possess the following minimum 

qualifications: 

3⁄4 Good common sense 

3⁄4 Good physical condition, including sight and hearing 

3⁄4 Mental alertness 

3⁄4 Courteous but firm manner 

3⁄4 Neat appearance 

3⁄4 Sense of responsibility for safety of public and crew 

3⁄4 Training in safe traffic control practices 

The use of hard hat and suitable clothing, such as an approved vest, shirt, or jacket, 

should be required for flaggers. For nighttime conditions, similar outside garments 

should be reflectorized. 

Flaggers are provided at work sites to stop traffic intermittently as necessitated by 

work progress. They also maintain continuous traffic past a work site at reduced 

speeds to help protect the work crew. For both of these functions, the flagger 

must, at all times, be clearly visible to approaching traffic for a distance sufficient 

to permit proper response by the motorist to the flagging instructions and to permit 

traffic to reduce speed before entering the work site. In positioning flaggers, 

consideration must be given to maintaining color contrast between the work area 

background and the flagger’s protective garments. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.11

Figure 3.3.10 Use of Hand Signaling Devices by Flagger (from Manual on 

Uniform Traffic Control Devices (MUTCD)) 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.12

The following methods of signaling with sign paddles should be used (see Figure 

3.3.10): 

3⁄4 To stop traffic - The flagger should face traffic and extend the STOP sign 

paddle in a stationary position with the arm extended horizontally away 

from the body. The free arm is raised with the palm toward approaching 

traffic. 

3⁄4 When it is safe for traffic to proceed - The flagger should face traffic with 

the SLOW sign paddle held in a stationary position with the arm extended 

horizontally away from the body. The flagger motions traffic ahead with 

the free hand. 

3⁄4 When it is desired to alert or slow traffic - The flagger shall face traffic 

with the SLOW sign paddle held in a stationary position with the arm 

extended horizontally away from the body. 

The following methods of signaling with a flag should be used: 

3⁄4 To stop traffic - The flagger should face traffic and extend the flag 

horizontally across the traffic lane in a stationary position so that the full 

area of the flag is visible hanging below the staff. For greater emphasis, 

the free arm may be raised with the palm toward approaching traffic. 

3⁄4 When it is safe for traffic to proceed - The flagger should stand parallel to 

the traffic movement and, with flag and arm lowered from view of the 

driver, motion traffic ahead with the free arm. Flags should not be used to 

signal traffic to proceed. 

3⁄4 Where it is desired to alert or slow traffic - The flagger should face traffic 

and slowly wave the flag in a sweeping motion of the extended arm from 

the shoulder level to straight down without raising the arm above a 

horizontal position. 

Lights approved by the appropriate highway authority or reflectorized sign paddles 

or reflectorized flags should be used to flag traffic at night. 

Whenever practicable, the flagger should advise the motorist of the reason for the 

delay and the approximate period that traffic will be halted. Flaggers and 

operators of machinery or trucks should be made to understand that every 

reasonable effort must be made to allow the driving public the right-of-way and 

prevent excessive delays. 

Flagger stations should be located far enough in advance of the work site so that 

approaching traffic will have sufficient distance to reduce speed before entering 

the project. This distance is related to the approach speed and physical conditions 

at the site; however, 60 to 90 m (200 to 300 feet) is desirable. In urban areas, 

where speeds are low and streets are closely spaced, the distance necessarily must 

be decreased. 

The flaggers should stand either on the shoulder adjacent to the traffic being 

controlled or in the barricaded lane (see Figure 3.3.11). At a spot obstruction, a 

position may have to be taken on the shoulder opposite the barricaded section to 

operate effectively. Under no circumstances should a flagger stand in the lane 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.13

being used by moving traffic. The flagger must be clearly visible to approaching 

traffic at all times. For this reason, the flagger must stand alone, never permitting 

a group of workers to congregate around the flagger station. The flagger should be 

stationed sufficiently in advance of the work force to warn them of approaching 

danger, such as out-of-control vehicles.

Figure 3.3.11 Flagger with Stop/Slow Paddle 

Flagger stations should be adequately protected and preceded by proper advance 

warning signs. At night, flagger stations should be adequately illuminated. 

At short lane closures where adequate sight distance is available for the safe 

handling of traffic, the use of one flagger may be sufficient. 

One-way Traffic 

Control 

Where traffic in both directions must, for a limited distance, use a single lane, 

provisions should be made for alternate one-way movement to pass traffic through 

the constricted work zone. At a spot obstruction, such as a short bridge, the 

movement may be self-regulating. However, where the one-lane section is of any 

length, there should be some means of coordinating movements at each end so that 

vehicles are not simultaneously moving in opposite directions in the work zone

and so that delays are not excessive at either end. Control points at each end of the 

route should be chosen so as to permit easy passing of opposing lines of vehicles. 

Alternate one-way traffic control may be facilitated by the following means: 

3⁄4 Flagger control 

3⁄4 Flag-carrying or official car 

3⁄4 Pilot car 

3⁄4 Traffic signals 

Flagger control is usually used for bridge inspection, where the one-lane section is 

short enough so that each end is visible from the other end. Traffic may be 

controlled by means of a flagger at each end of the section. One of the two should 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.14

be designated as the chief flagger to coordinate movement. They should be able to 

communicate with each other verbally or by means of signals. These signals 

should not be such as to be mistaken for flagging signals. 

Where the end of a one-way section is not visible from the other end, the flaggers 

may maintain contact by means of radio or field telephones. So that a flagger may 

know when to allow traffic to proceed into the section, the last vehicle from the 

opposite direction can be identified by description or license. 

Shadow Vehicles Shadow Vehicles with truck Mounted attenuators (TMAs) are used to prevent 

vehicles from entering the work zone if the motorist drifts into the lane closure. 

Each agency has its own specific requirements, but a shadow vehicle should 

generally be employed any time a shoulder or travel lane will be occupied by 

workers or equipment. 

3⁄4 The requirements for the truck itself vary, but high visibility with flashing 

lights, a striped panel, or an arrow board on the rear of a vehicle of a 

specified minimum weight are generally required. 

3⁄4 Some agencies recommend the use of truck or trailer mounted attenuators

(see Figure 3.3.12). This protects the motorist, as well as the inspectors. 

Figure 3.3.12 Shadow Vehicle with Attenuator 

Police Assistance On some inspection jobs, police assistance may be helpful and even required. The 

presence of a patrol car aids in slowing and controlling the public. At a signalized 

intersection near a job site, a police officer may be required to ensure traffic flows 

properly and smoothly. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.15

3.3.6 

Public Safety Since the fundamental goal of bridge inspection is to enhance public safety, it 

would make little sense to endanger that same public by inadequate traffic control 

measures. Traffic control does take time, money, and effort. It is, however, a 

necessary part of the business of bridge inspection. 

In the broadest sense, the motorist is the customer of everyone in the transportation 

industry. Like everyone else, bridge inspectors need to treat customers well by

inconveniencing them as little as possible and protecting their safety. This means 

providing well thought out, clear, and effective traffic control measures. 

Pedestrians also must be considered. If a walkway must be closed, it should be 

properly signed and barricaded. An alternate route for the pedestrian should be 

indicated, if necessary through or preferably around the work zone. 

Training Each person whose actions affect inspection, maintenance and construction zone 

safety (from the upper-level management personnel to construction and 

maintenance field personnel) should receive training appropriate to the job 

decisions each individual is required to make. Only those individuals who are 

qualified by means of adequate training in safe traffic control practices and have a 

basic understanding of the principles established by applicable guidelines and 

regulations should supervise the selection, placement, and maintenance of traffic 

control devices in bridge safety inspection, maintenance, and construction areas. 

Responsibility Legally and morally, it is the inspector’s responsibility to follow the regulations 

and guidelines of the agency having jurisdiction. 

The primary goal of good traffic control is safety – safety of the workers,

motorists, and pedestrians. A secondary goal is to be able to defend yourself and 

your employer should there be an accident. Accidents bring lawsuits. Lawsuits 

bring inquiries about who is responsible. One thing investigated during a lawsuit 

will be whether or not the standards and regulations were followed. Anything not 

done in accordance with published standards, regulations, and directives could 

bring blame upon whoever violated the regulation. Being blamed for an accident is 

expensive and damaging. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.3: Traffic Control 

3.3.16

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3.4-i

Table of Contents

Section 3 ..................................................................................................................................................

Fundamentals of 

Bridge Inspection 

 3.4 Inspection Equipment ............................................................................ 3.4.1 

 3.4.1 Equipment Necessity ................................................................ 3.4.1 

 3.4.2 Standard Tools .......................................................................... 3.4.1 

 Tools for Cleaning.............................................................. 3.4.3 

 Tools for Inspection............................................................ 3.4.3 

 Tools for Visual Aid........................................................... 3.4.4 

 Tools for Measuring ........................................................... 3.4.4 

 Tools for Documentation.................................................... 3.4.4 

 Tools for Access................................................................. 3.4.5 

 Tools for Miscellaneous Equipment................................... 3.4.5 

 

 3.4.3 Special Equipment .................................................................... 3.4.5 

 Survey Equipment .............................................................. 3.4.5 

 Nondestructive Testing Equipment .................................... 3.4.5 

 Underwater Inspection Equipment ..................................... 3.4.5 

 Other Special Equipment.................................................... 3.4.6 

 3.4.4 Recent Developments in Equipment......................................... 3.4.6 

 Rotary Percussion............................................................... 3.4.6 

 Scour Measurement............................................................ 3.4.7 

 Scour Monitoring................................................................ 3.4.7 

 Scour Watch................................................................. 3.4.7 

 Scan Monitoring Collar................................................ 3.4.7 

 Remote Camera......................................................................... 3.4.8 

 High Speed Under Clearance Measurement System .............. 3.4.10 

 Robots ................................................................................... 3.4.10 

 Laser Scanning........................................................................ 3.4.10 

 Data Recording ....................................................................... 3.4.11 

 Hardware .......................................................................... 3.4.11 

 Software............................................................................ 3.4.11 

 3.4.5 Primary Safety Concerns ........................................................ 3.4.12 
SECTION 3: Fundamentals of Bridge Inspection 

 TOPIC 3.4: Inspection Equipment 

3.4-ii

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3.4.1 

Topic 3.4 Inspection Equipment 

3.4.1 

Equipment 

Necessity 

Several factors play a role in what type of equipment is needed for an inspection. 

Bridge location and type are two of the main factors in determining equipment 

needs. If the bridge is located over water, certain pieces of equipment such as life 

jackets and boats are important to have. Also, if the bridge is made of timber, then 

specific pieces of equipment like increment borers and ice picks are needed, 

whereas they would not be necessary on a steel or concrete bridge. Another factor 

influencing equipment needs is the type of inspection. It is therefore important to 

review every facet about the bridge before beginning an inspection. A few 

minutes spent reviewing the bridge files and making a list of the necessary 

equipment can save hours of wasted inspection time in the field if the inspectors 

do not have the required equipment. 

3.4.2 

Standard Tools In order for the inspector to perform an accurate and comprehensive inspection, 

the proper tools must be used. Standard tools that an inspector should have 

available at the bridge site can be grouped into seven basic categories: 

3⁄4 Tools for cleaning (see Figure 3.4.1) 

3⁄4 Tools for inspection (see Figure 3.4.2) 

3⁄4 Tools for visual aid (see Figure 3.4.3) 

3⁄4 Tools for measuring (see Figure 3.4.4) 

3⁄4 Tools for documentation 

3⁄4 Tools for access 

3⁄4 Miscellaneous equipment 

Figure 3.4.1 Tools for Cleaning
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.2 

Figure 3.4.2 Tools for Inspection

Figure 3.4.3 Tools for Visual Aid
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.3 

Figure 3.4.4 Tools for Measuring

Tools for Cleaning Tools for cleaning include: 

3⁄4 Wisk broom - used for removing loose dirt and debris 

3⁄4 Wire brush - used for removing loose paint and corrosion from steel 

elements 

3⁄4 Scrapers (2 inch or 50 mm) - used for removing corrosion or growth from 

element surfaces 

3⁄4 Flat bladed screwdriver - used for general cleaning and probing 

3⁄4 Shovel - used for removing dirt and debris from bearing areas

Tools for Inspection Tools for inspection include: 

3⁄4 Pocket knife - used for general duty 

3⁄4 Ice pick - used for surface examination of timber elements 

3⁄4 Hand brace and bits - used for boring suspect areas of timber elements 

3⁄4 Increment borer - used for internal examination of timber elements 

3⁄4 Chipping hammer with leather holder (16 ounce geologist's pick) - used 

for loosening dirt and rust scale, sounding concrete, and checking for 

sheared or loose fasteners 

3⁄4 Plumb bob - used to measure vertical alignment of a superstructure or 

substructure element 

3⁄4 Tool belt with tool pouch - used for convenient holding and access of 

small tools 

3⁄4 Chain drag - used to identify areas of delamination on concrete decks 

3⁄4 Range pole / probe - used for probing for scour holes 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.4 

Tools for Visual Aid Tools for visual aid include: 

3⁄4 Binoculars - used to preview areas prior to inspection activity and for 

examination at distances 

3⁄4 Flashlight - used for illuminating dark areas 

3⁄4 Lighted magnifying glass (e.g., five power and 10 power) - used for close 

examination of cracks and areas prone to cracking 

3⁄4 Inspection mirrors - used for inspection of inaccessible areas (e.g., 

underside of deck joints) 

3⁄4 Dye penetrant - used for identifying cracks and their lengths 

Tools for Measuring Tools for measuring include: 

3⁄4 Pocket tape (6 foot rule) - used to measure defects and element and joint 

dimensions 

3⁄4 25 foot and 100 foot tape - used for measuring component dimensions 

3⁄4 Calipers - used for measuring the thickness of an element beyond an 

exposed edge 

3⁄4 Optical crack gauge - used for precise measurements of crack widths 

3⁄4 Paint film gauge - used for checking paint thickness 

3⁄4 Tiltmeter and protractor - used for determining tilting substructures and 

for measuring the angle of bearing tilt 

3⁄4 Thermometer - used for measuring ambient air temperature and 

superstructure temperature 

3⁄4 4 foot carpenter's level - used for measuring deck cross-slopes and 

approach pavement settlement 

3⁄4 D-Meter (ultrasonic thickness gauge) - used for accurate measurements of 

steel thickness 

3⁄4 Electronic Distance Meter (EDM) - used for accurate measurements of 

span lengths and clearances when access is a problem 

3⁄4 Line level and string line 

Tools for Documentation Tools for documentation include:

3⁄4 Inspection forms, clipboard, and pencil - used for record keeping for most 

bridges 

3⁄4 Field books - used for additional record keeping for complex structures 

3⁄4 Straight edge - used for drawing concise sketches 

3⁄4 35 mm camera - used for visual documentation of the bridge site and 

conditions 

3⁄4 Polaroid camera - used to provide instant documentation for serious 

conditions which require immediate review by office personnel 

3⁄4 Digital camera - used to provide digital images of defects which can be 

downloaded and e-mailed for instant assessment 

3⁄4 Chalk, keel, paint sticks, or markers - used for element and defect 

identification for improved organization and photo documentation 

3⁄4 Center punch - used for applying reference marks to steel elements for 

movement documentation (e.g., bearing tilt and joint openings) 

3⁄4 "P-K" nails - Parker Kalon masonry survey nails used for establishing a 

reference point necessary for movement documentation of substructures 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.5 

and large cracks 

Tools for Access Some common tools for access include: 

3⁄4 Ladders - used for substructures and various areas of the superstructure 

3⁄4 Boat - used for soundings and inspection; safety for over water work 

3⁄4 Rope - used to aid in climbing 

3⁄4 Waders - used for shallow streams 

Tools for access are described in further detail in Topic 3.5.2. 

Miscellaneous Equipment Miscellaneous equipment should include: 

3⁄4 "C"-clamps - used to provide a "third hand" when taking difficult 

measurements 

3⁄4 Penetrating oil - aids removal of fasteners, lock nuts, and pin caps when 

necessary 

3⁄4 Insect repellent - reduces attack by mosquitoes, ticks, and chiggers 

3⁄4 Wasp and hornet killer - used to eliminate nests to permit inspection 

3⁄4 First-aid kit - used for small cuts, snake bites, and bee stings 

3⁄4 Dust masks or respirators - used to protect against inhalation in dusty 

condition or work around pigeon droppings 

3⁄4 Coveralls - used to protect clothing and skin against sharp edges while 

inspecting 

3⁄4 Life jacket - used for safety over water 

3⁄4 Cell phone - used to call in emergencies 

3⁄4 Toilet paper - used for other "emergencies" (better safe than sorry) 

3.4.3 

Special Equipment For the routine inspection of a common bridge, special equipment is usually not 

necessary. However, with some structures, special inspection activities require 

special tools. These special activities are often subcontracted by the agency 

responsible for the bridge. The inspector should be familiar with special 

equipment and its application. 

Survey Equipment Special circumstances may require the use of a transit, a level, an incremental rod, 

or other survey equipment. This equipment can be used to establish a component's 

exact location relative to other components, as well as an established reference 

point. 

Nondestructive Testing 

Equipment 

Nondestructive testing (NDT) is the in-place examination of a material for 

structural integrity without damaging the material. NDT equipment allows the 

inspector to "see" inside a bridge element and assess deficiencies that may not be 

visible with the naked eye. Generally, a trained technician is necessary to conduct 

NDT and interpret their results. For a more detailed description of NDT, refer to 

Topics 13.1.2, 13.2.2, and 13.3.2. 

Underwater Inspection 

Equipment 

Underwater inspection is the examination of substructure units and the channel 

below the water line. When the waterway is shallow, underwater inspection can 

be performed above water with a simple probe. Probing can be performed using a 

range pole, piece of reinforcing steel, a survey rod, a folding rule, or even a tree 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.6 

limb. 

When the waterway is deep, underwater inspection must be performed by trained 

divers. This requires special diving equipment that includes a working platform, 

fathometer, ground penetrating radar, air supply systems, radio communication, 

and sounding equipment. Refer to Topic 11.3 for a more detailed description of 

underwater inspection equipment. 

Other Special Equipment An inspection may require special equipment to prepare the bridge prior to the 

inspection. Such special equipment includes: 

3⁄4 Air-water jet equipment - used to clean surfaces of dirt and debris 

3⁄4 Sand or shot blasting equipment - used to clean steel surfaces to bare metal

3⁄4 Burning, drilling, and grinding equipment 

3.4.4 

Recent 

Developments in 

Equipment 

In addition to the standard and special equipment listed previously, there are new 

equipment and technology available to aid in bridge inspection. The developments 

in various types of advanced testing techniques are described in Topics 13.1, 13.2 

and 13.3. The following information represents some of the advances in 

inspection tools and data collection. 

Rotary Percussion Rotary percussion is a technique whereby a uniform tapping is produced by rolling 

a gear-toothed wheel to determine concrete defects. This allows for quicker 

inspection on overhead and vertical surfaces, similar to using a chain drag for 

horizontal surfaces. Advantages of rotary percussion testing tools include ability to 

detect near-surface delaminations, quickness of testing, low equipment cost, 

relatively low level of user’s skill required, and low sensitivity to the surroundings.

Figure 3.4.5 Rotary Percussion 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.7 

Scour Measurement The SHIFLO is a specialized device used to measure the depth of scour during 

flood flows. It consists of a depth finder mounted on a water ski. The use of a

water ski allows for depth readings of be taken in extremely fast flowing water and 

also allows for excellent maneuverability of the depth finder into locations under a 

bridge. 

Scour Monitoring ScourWatchTM 

ScourWatchTM, is a secure web-based bridge scour monitoring software product 

that allows transportation engineers to predict, identify, prepare for, and record 

potentially destructive flooding events. ScourWatchTM identifies the occurrence of 

a flood event and collects and processes relevant bridge information, several 

sources of real-time hydrological and any bridge scour monitoring device data. 

Transportation officials will be able to efficiently dispatch emergency personnel, 

bridge safety inspectors, and maintenance workers before, during, and after a flood 

event affects a state's bridge inventory. 

ScourWatchTM is designed to be an active/pro-active bridge scour monitoring 

system. Creates a list of scour critical bridges experiencing their respective critical 

event. 

Scour Monitoring Collar 

The Magnetic Sliding Collar (MSC) is a scour monitoring device. The magnetic 

sliding collar device consists of a stainless steel pipe driven into the channel 

bottom with a sliding collar that drops down the pipe as the scour progresses. The 

location of the collar is detected by the magnetic field created by magnets on the 

collar. Installations conducted in cooperation with state highway agencies 

demonstrated that this simple, low-cost instrument is adaptable to various field 

situations, and can be installed with the equipment and technical skills normally 

available at the district level of a state highway agency. 

Figure 3.4.6 Scour Monitoring Collar 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.8 

 

Figure 3.4.7 Scour Monitoring Collar Schematic 

Remote Camera The basic components of computer-based image system include an imaging 

sensor, most commonly solid-state camera; the image acquisition boards, which 

convert optical images into an array of digital information, representing the 

brightness values of the surface; and dedicated processor. The computer-based 

imaging system can provide two main types of information: spatial measurements 

and surface analysis. Spatial information encompasses two-dimensional or threedimensional analysis, measurements and recognition. The surface analysis 

provides information regarding the color or gray-scale attributes of the target. For 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.9 

example, imaging systems are able to distinguish a flaw from the rest of the 

surface, and determine size, shape, location and even smallest color attributes of 

the defect. The field of view that can be processed in a fraction of the second and 

can be on the order of 200 to 500 times the size of the smallest feature of interest. 

Figure 3.4.8 Remote Camera 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.10

High Speed 

Underclearance 

Measurement System 

The system can mount on any vehicle with a trailer hitch receiver. The system 

measures the underclearance of a bridge at normal highway speeds. Along with 

the underclearance data, the GPS information is gathered. Software is used for the 

data acquisition, display and analysis. The bridge beam height is read to the 

nearest tenth of a foot. The GPS information can be pasted into a map program to 

obtain the structure location for future reference. 

Figure 3.4.9 High Speed Underclearance Measurement System 

Robots Robotic devices for many applications are being developed by university 

researchers. High level and underwater bridge inspection are among these 

applicatons. 

One example is the serpentine robot being developed that possesses multiple joints 

that give it a superior ability to flex, reach, and approach all points on the bridge. 

This robot is under development. 

Other developments in robotic devices are discussed in more detail in Topic 13.3. 

Laser Scanning Laser scanning technology can create accurate and complete 3D as-built models 

quickly and safely. These digital models are automatically combined with CAD 

design models to allow generation of “as-built” drawings for existing structures. 

This method can replace tedious field measurements for rehabilitation projects. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.11

Data Recording Hardware 

Data recording hardware can include regular office computers, notebook 

computers, tablet PCs or PDAs (pen based tablets). Some versions of these 

devices have been made to be more rugged and even “wearable” for use in the 

field. 

Many State agencies are using Electronic Data Collection for bridge inspection. 

See Topic 3.X for a detailed description of the hardware and software some State 

agencies are using. 

Software 

Specialized software packages can provide a comprehensive set of solutions to 

manage, inspect, maintain and repair bridges. They allow the user to maintain a 

comprehensive asset inventory database, collect inspection data from electronic 

devices, keep history of inspection & maintenance records, assign inspection & 

maintenance requirements to each structural component, automatically generate 

inspection reports, and offer decision support. 

 

Figure 3.4.10 Pen Based Tablet
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.4: Inspection Equipment 

3.4.12

3.4.5 

Primary Safety 

Concerns 

Proper inspection equipment can play a key role in maintaining the safety for the 

traveling public and the inspectors. When inspectors do not have the right 

equipment, they may attempt to use an alternate piece of equipment that is not 

really designed for the job. This cannot only prove dangerous for the inspector, 

but for the public as well. Inspectors should never try to substitute with improper 

inspection equipment in the interest of saving time or money. The best way to 

avoid these circumstances is to ensure the inspectors have the proper equipment 

for the job and that equipment is serviced or replaced periodically. This 

responsibility lies not only with the inspector but also their employer. It is 

important that the employer make every effort to properly equip all inspection

teams. Also, the inspector should be familiar with every piece of equipment and 

how to use and operate it properly and safely. 
3.5-i

Table of Contents

Section 3 ..................................................................................................................................................

Fundamentals of 

Bridge Inspection 

 3.5 Methods of Access................................................................................. 3.5.1 

 3.5.1 Introduction............................................................................... 3.5.1 

 3.5.2 Types of Access Equipment...................................................... 3.5.1 

 Ladders ............................................................................... 3.5.1 

 Rigging ............................................................................... 3.5.2 

 Scaffolds............................................................................. 3.5.4 

 Boats or Barges .................................................................. 3.5.4 

 Climbers ............................................................................. 3.5.5 

 Floats .................................................................................. 3.5.6 

 Bosun (or Boatswain) Chairs / Rappelling......................... 3.5.6 

 Free Climbing..................................................................... 3.5.7 

 Permanent Inspection Structures ........................................ 3.5.7 

 Catwalks....................................................................... 3.5.8 

 Traveler........................................................................ 3.5.8 

 Handrails...................................................................... 3.5.9 

 Inspection Robots............................................................. 3.5.10 

 3.5.3 Types of Access Vehicles ....................................................... 3.5.10 

 Manlift.............................................................................. 3.5.10 

 Bucket Truck .................................................................... 3.5.10 

 Underbridge Inspection Vehicle....................................... 3.5.11 

 3.5.4 Method of Access and Cost Efficiency................................... 3.5.13 

3.5.5 Safety Considerations ............................................................. 3.5.14 

 Access Equipment ............................................................ 3.5.14 

 Access Vehicles................................................................ 3.5.14 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5-ii

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3.5.1

Topic 3.5 Methods of Access 

3.5.1 

Introduction The two primary methods of gaining access to hard to reach areas of a bridge are 

access equipment and access vehicles. Common access equipment includes 

ladders, rigging, and scaffolds, while common access vehicles include manlifts, 

bucket trucks, and snoopers. In most cases, using a manlift or bucket truck will be 

less time consuming than using a ladder or rigging to inspect a structure. The time 

saved, however, must offset the higher costs associated with operating access 

vehicles. 

3.5.2 

Types of Access 

Equipment 

The purpose of access equipment is to position the inspector close enough to the 

bridge component so that a "hands-on" inspection can be performed. The 

following are some of the most common forms of access equipment. 

Ladders Ladders can be used for inspecting the underside of a bridge or for inspecting 

substructure units. However, a ladder should be used only for those portions of the 

bridge that can be reached safely, without undue leaning or reaching. 

Figure 3.5.1 Inspection with a Ladder

Ladders can also be used to climb down to access elements of the bridge. The 

hook-ladder, as it is commonly referred to, is fastened securely to the bridge 

framing. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.2

Figure 3.5.2 Use of a Hook-ladder

When using a hook-ladder, the inspector should be tied off to a separate safety 

line, independent of the ladder. 

Rigging Rigging of a structure consists of cables and platforms. Rigging is used to gain 

access to floor systems and main load carrying members in areas where access by 

other means is not feasible or where special inspection procedures are required 

(e.g., nondestructive testing and pin removal). Rigging is often used over water, 

over busy highways or railroads where sufficient clearance exists. Rigging is a 

good choice for a load posted bridge that does not have the capacity to support an 

inspection vehicle. 

Figure 3.5.3 Rigging for Substructure Inspection
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.3

Figure 3.5.4 Rigging for Superstructure Inspection 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.4

Scaffolds Scaffolds provide an efficient access alternative for structures that are less than 12 

m (40 feet) high and over level ground with little or no traffic nearby. 

Figure 3.5.5 Scaffold

Boats or Barges A boat or barge may be needed for structures over water. A boat can be used for 

inspection, as well as providing access to areas for taking photographs. Also, a 

safety boat is required when performing an inspection over water. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.5

Figure 3.5.6 Inspection Operations from a Barge 

A barge may also be used in combination with other access equipment or vehicles 

to perform an inspection. The barge may be temporarily anchored in place to 

provide a platform for a manlift or for underwater inspections. 

Climbers Climbers are mobile inspection platforms or cages that "climb" steel cables. They 

are well suited for the inspection of high piers and other long vertical faces of 

bridge members. 

Figure 3.5.7 Climber 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.6

Floats A float is a wood plank work platform hung by ropes. Floats are generally used 

for access in situations where the inspector will be at a particular location for a 

relatively long period of time. 

Figure 3.5.8 Float (foreground) and Spider (background) 

Bosun (or Boatswain) 

Chairs / Rappelling 

Bosun (or boatswain) chairs are suspended with a rope and can carry only one 

inspector at a time. They can be raised and lowered with block and tackle devices. 

Rappelling is a similar access method to the Bosun chair but utilizes different 

equipment and techniques. However, both methods require the use of independent 

safety lines. 

Figure 3.5.9 Bosun Chair 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.7

Free Climbing On some structures, if other methods of access are not practical, inspectors must 

climb the bridge elements. Safety awareness should be foremost in the inspector's 

mind when utilizing this technique. Climbing can be divided into two categories. 

The first category is free climbing, in which the inspector climbs freely, unsecured 

to the bridge. (Whenever possible, a safety line should be provided for the 

inspector to secure a lanyard.) The second category employs rappelling techniques 

and safety equipment. 

Figure 3.5.10 Climbing 

Permanent Inspection 

Structures 

On some structures, inspection access is included in the design and construction of 

the bridge. These are typically found on long span structures or more complex 

designs. Although these inspection platforms only give access to a limited portion 

of the bridge, they do provide a safe and effective means for the inspector to work. 

The following are some examples of permanent inspection structures. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.8

 Catwalks 

A catwalk is an inspection platform typically running parallel to the girders from 

abutment to abutment under the superstructure. Catwalks can be used to inspect 

parts of the deck/superstructure and some portions of the substructure. The range 

of inspection area is limited to those locations near the catwalk. 

Figure 3.5.11 Catwalk 

 Traveler 

A traveler is another permanent inspection platform similar to a catwalk except 

that it is movable. A traveler platform is typically perpendicular to the girders 

and the platform runs on a rail system between substructure elements. Having the 

platform perpendicular to the girders allows the inspectors a wider range of 

movement and enables them to see more if not all of the superstructure elements. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.9

Figure 3.5.12 Traveler Platform 

 Handrails 

Handrails are also used to aid an inspector. Handrails can be used in a number of 

different locations on the bridge. On the main suspension cables, on top of the pier 

caps, and on the girder web are just a few locations where handrails may be built. 

Handrails are typically provided to assist the inspector when free climbing on the 

bridge and give the inspector a place to secure their lanyard and safety harness. 

Figure 3.5.13 Handrail 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.10

Inspection Robots Currently, efforts are being made for robots to be used for inspection purposes. 

Though still early in the development stage, robots may prove to be an important 

addition to the inspector’s access equipment. Although a robot can never replace a 

qualified inspector, it can provide information that may not be visible to the human 

eye. A robot equipped with sonar capabilities can detect internal flaws in bridge 

members. Also, a robot can be used in situations that are too difficult to reach or 

extremely dangerous for a human. 

3.5.3 

Types of Access 

Vehicles 

There are many types of vehicles available to assist the inspector in gaining access 

for “hands-on” inspection of bridge elements. The following are some of the most 

common types of access vehicles. 

Manlift A manlift is a vehicle with a platform or bucket capable of holding one or more 

inspectors. The platform is attached to a hydraulic boom that is mounted on a 

carriage. An inspector "drives" the carriage using controls in the platform. This 

type of vehicle is usually not licensed for use on highways. However, some 

manlifts are nimble and can operate on a variety of terrains. Although four wheel 

drive models are available, manlifts are limited to use on fairly level terrain. 

Manlifts come in a number of different sizes with vertical reaches ranging from 12 

m (40 feet) to over 52 m (170 feet). 

Figure 3.5.14 Manlift

Bucket Truck A bucket truck is similar to a manlift. However, a bucket truck can be driven on a 

highway, and the inspector controls only the bucket. As with the manlift, a bucket 

truck should be used on fairly level terrain. Bucket trucks have a number of 

different features and variations: 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.11

3⁄4 Lift capability - varies 7.5 to 15 m (25 to 50 feet). 

3⁄4 Rotating turret - turning range (i.e., the rotational capability of the turret) 

varies with each vehicle. 

3⁄4 Outriggers - bucket trucks that offer extended reach and turning range 

have outriggers or supports that are lowered from the chassis of the 

vehicle to help maintain stability. 

3⁄4 Telescoping boom - some booms may be capable of extending and 

retracting, providing a greater flexibility and reach area from a given truck 

location. 

3⁄4 Truck movement - some vehicles offer stable operations without 

outriggers and can move along the bridge during inspection activities. 

Vehicles that require outriggers for stable operations cannot be moved 

during the inspection unless the outriggers have wheels. 

3⁄4 Multiple booms - some bucket trucks have more than one boom, and 

provide reach up to 15 m (50 feet). 

Figure 3.5.15 Bucket Truck 

Underbridge Inspection 

Vehicle 

An underbridge inspection vehicle is a specialized bucket truck with an articulated 

boom designed to reach under a structure while parked on the bridge deck. A 

rotating turret provides maximum flexibility, and outriggers with wheels allow the 

truck to be moved during operations. Usually the third boom has the capacity for 

extending and retracting, allowing for greater reach under a structure. Some of the 

larger underbridge inspection vehicles have four booms, allowing an even greater 

reach. 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.12

Figure 3.5.16 Underbridge Inspection Vehicle 

Many of the features on an underbridge inspection vehicle are standardized on all 

models. Some of the common features include: 

3⁄4 Rotating turret - provides maximum flexibility. 

3⁄4 Outriggers with wheels - allow for moving the truck during operations. 

3⁄4 Telescoping third boom - usually the third boom has the capability for 

extending and contracting; this allows for greater reach under a structure. 

Variations and options available on different models include: 

3⁄4 Capacity - Some underbridge inspection vehicles have a two or three 

person bucket on the end of the third boom. Other models are equipped 

with a multiple-person platform on the third boom with a ladder on the 

second boom. Still other models may have the capability of interchanging 

a bucket and a platform in the shop. 

3⁄4 Platform – The platform is lowered by an articulated boom and can then 

telescope out to provide inspection access to a wide range of the 

superstructure and substructure. The inspector is now free to walk from 

beam to beam without having to reposition the platform. This 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.13

combination allows for an efficient and thorough inspection. 

3⁄4 Telescoping second boom - Some underbridge inspection vehicle models 

have a second boom that can extend and contract, providing greater 

movement in the vertical direction. 

3⁄4 Articulated third (or fourth) boom - Some underbridge inspection vehicle 

models have a small third or fourth boom that allows for greater vertical 

movement under the structure. This option is particularly useful on 

bridges with deep superstructure members.

Figure 3.5.17 Underbridge Inspection Vehicle (Snooper) with Platform 

3.5.4 

Method of Access 

and Cost Efficiency 

In most cases, even the most sluggish lift device will be quicker than using a 

ladder or rigging to inspect a structure. The time saved, however, must offset the 

higher costs associated with obtaining and operating the vehicle. 

In assessing the time-saving effectiveness of a lift device, the following questions 

should be answered: 

3⁄4 Can the bridge be inspected by other reasonable methods? 

3⁄4 What types of access vehicle or access equipment are available? 

3⁄4 How much of the bridge can be inspected using the access vehicle? 

3⁄4 How much of the bridge can be inspected from one setup of the access 

vehicle? 

3⁄4 How much time does it take to inspect at each setup? 

3⁄4 How much time does it take to move from one setup to the next? 
SECTION 3: Fundamentals of Bridge Inspection 

TOPIC 3.5: Methods of Access 

3.5.14

3⁄4 Does the vehicle require an independent operator or driver other than the 

inspector? 

3⁄4 Will the use of the access vehicle require special traffic control? 

3⁄4 Can the bridge carry the weight of an inspection vehicle? 

The inspection time and vehicle costs can then be compared to costs associated 

with using standard access equipment.

3.5.5 

Safety 

Considerations 

Safety should be a primary concern on any job site, not only of the workers but of 

the public as well. The equipment and vehicles being used also have safety 

considerations. 

Access Equipment Before the bridge inspection begins, an equipment inspection should be performed. 

As a minimum, inspect access equipment as per the manufacture’s guidelines. 

Using faulty equipment can lead to serious accidents and even death. The 

inspector should check all the equipment and verify that it is in good working 

condition with no defects or problems. If rigging or scaffolding is being used, it 

should be checked to ensure that it was installed properly and all cables and planks 

are secured tightly. OSHA-approved safety harnesses with shock absorbing 

lanyards should be worn at all time when using access equipment and vehicles. 

Access Vehicles If the inspector is not familiar with the inspection vehicle being used, he should 

take the time required to become accustomed to the operation. In some cases, 

formal operator training may be necessary or required. When operating any 

inspection vehicle, always be aware of any overhead power lines or any other 

hazards that may exist. It is also important to be aware of any restrictions on the 

vehicle, such as weight limits for the bucket, support surface slope limits, and 

reach restrictions. Always be alert to your location. Do not boom out into unsafe 

areas such as unprotected traffic lanes or near electrical lines.