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Construction Program Management and Inspection Guide

Appendix D - Guide for Making Inspections-in-Depth on Federal-Aid Highway Construction Projects


Purpose of Inspections-in-Depth

The need for and purpose of making inspections on Federal-aid highway construction projects can be found in 23 United States Code (USC). Representing the Secretary of Transportation, we are charged with certain responsibilities. 23 USC 114 states:

The construction of any highways or portions of highways located on the Federal-aid system shall be undertaken by the respective State transportation departments or under their direct supervision...such construction shall be subject to the inspection and approval of the Secretary.

This responsibility is further clarified in memoranda dated June 22, 2001, Policy on the Stewardship and Oversight of the Federal Highway Programs, and January 8, 2003, Stewardship and Oversight of the FHWA Construction Programs (see Appendix A).

It is recognized that because of staffing and time limitations, it will not be possible to make thorough inspections of all active projects with FHWA oversight. From time to time, however, the division field engineer should designate a number of representative projects upon which comprehensive, thorough, complete, and detailed inspections and analyses of a selected phase or phases of the construction and engineering are to be made. The primary purpose of an inspection-in-depth (IID) and analysis of the findings is to evaluate the accuracy, adequacy, and effectiveness of procedures, methods, controls, and operations used by the contractor and the State to assure high quality construction, accurate determination of quantities, and correct payment in accordance with the contract provisions. Should the findings on these inspections disclose the need for additional controls, supervision, or improvements, a statewide process review/product evaluation (PR/PE) should be conducted.

Intent of Guide

IIDs, like PR/PEs, are a tool to support the State transportation agency's (STA's) construction management program. This guide is intended to provide assistance to field engineers in the performance of IIDs. It is neither practicable nor desirable to specify precisely each step to be taken on an IID because of the many variations encountered on different projects and the specific reasons for making a particular inspection. It is expected that divisions may supplement this guide by adding material applicable to the conditions in their particular jurisdictions.

Scope of Inspection-in-Depth

IIDs may be specific or broad in nature. Steps presented herein are intended to facilitate the inspection of the more common types of work and to obtain a reasonable degree of uniformity. This guide is not a substitute for the exercise of good judgment, especially in determining the scope and depth of the inspection.

Refer to the generic inspection guidelines linked to the FHWA headquarters Construction and Maintenance Web page (https://www.fhwa.dot.gov/construction/).

Basis of Evaluation

Base the engineering evaluation of construction work on the approved plans, specifications, special provisions, contract provisions and applicable agency standards, instruction manuals, and operating procedures. Ensure that program or project concerns are brought to the attention of the appropriate officials with a recommendation for effecting desirable improvements on present and future work.

Responsibility of Inspecting Engineer

The field engineer is directly responsible for all work in his or her assigned area. Make the IID as defined in the division's operating procedures. If specialized knowledge of the construction project work is necessary, ensure that the IID is a team effort with the appropriate technical specialists as team members.

Reach agreement with State personnel on corrective action that will be taken to address findings, and establish a time frame for implementing the action. Elevate the discussion to the STA's resident engineer, district office, or central office if required. Notify the FHWA division office if a condition or deficiency requires immediate attention and resolution cannot be obtained on-site. In situations where immediate attention is not required, the following approaches are available to assure the appropriate action is taken:

  1. Transmit the inspection report by letter requesting appropriate corrective action (this should always be the first step when resolution cannot be resolved at the project level).
  2. Make the affected item of work nonparticipating.
  3. Suspend Federal participation in progress payments (49 CFR 18.43).
  4. Make the project nonparticipating.

The goal is for FHWA field engineers and STA field personnel to reach agreement on appropriate action to address findings of concern; in rare situations, more aggressive action is required. Consult with the FHWA division office management when these situations occur.

Selection of Project or Phase of Operations

Select the particular projects and phases of operations for an IID in consultation with your supervisor and construction management program. Base the selection on defined objectives. Schedule the inspection of any individual phase when that particular phase is actively under way on the project. Evaluate new construction techniques whenever possible and prepare a summary report for posting on the FHWA headquarters Construction Web page (https://www.fhwa.dot.gov/construction/).

Frequency of Inspections-in-Depth

The number and frequency of IIDs will vary according to the need for such reviews and according to the availability of personnel to make them. Inspections-in-depth are preferred to more general contact reviews. Contact reviews typically do not provide adequate knowledge of the substantive operations underway. Contact reviews do provide an opportunity to review project time and cost status, as well as to maintain rapport with the project team. Within each division, there will be certain areas of the State that will warrant more emphasis than others; similarly, there will be certain phases of operations that will require more concentration of effort.

Time Required for Inspection

The time required for each inspection will depend upon the extent of inquiry and investigation considered warranted by the circumstances encountered and the number of construction operations involved. Ensure that sufficient time is available to thoroughly investigate the phases of the operations that are the objective of the inspection. Adequate review of paving operations on a major project, for example, may require about three days at the project site.

Contract Documents

Prior to visiting the site of the project selected for inspection, study the plans and specifications governing the work to assure familiarity with all phases of the project. Place special emphasis on the features that are anticipated to be the focal points of concern during the inspection. In States where the contractor is required to develop a project-specific quality control plan, ensure that the plan is an integral part of any IID that involves material or product acceptance.

State Construction and Materials Manuals

Prior to visiting the site of the project selected for inspection, review the STA's construction and materials manuals for applicability to the work. These documents set forth the basic operating instruction to STA field personnel and generally define inspection and acceptance procedures.

Quality Assurance Requirements

23 CFR 637 sets forth the policies, procedures, and guidelines to assure the quality of materials and construction on Federal-aid highway NHS projects. Become familiar with the requirements within this regulation and ensure that they are being properly administered on the project. Focus specific attention on these processes:

  • Random quality control sampling and testing performed by qualified personnel employed by the contractor or vendor.
  • Random verification sampling and testing by qualified testing personnel employed by the STA or its designated agent, excluding the contractor or vendor (split samples not acceptable).
  • Optional use of contractor's quality control for the acceptance decision when properly verified by the owner.
  • Use of qualified laboratories for all testing of materials as a basis of acceptance.
  • Independent assurance sampling and testing by qualified personnel employed by the STA or its designated agent, excluding the contractor or vendor.
Evaluation of Project Personnel

Evaluate the STA and contractor personnel assigned to the project for adequacy as to number, knowledge, skills, and abilities. Consider findings made on previous inspections on the same project or other projects that may be reoccurring.

Obtain information by general and technical discussion of the work and by reviewing diaries and project records. Strive for open communication and to develop an atmosphere of trust. Avoid focusing on minor issues of very low risk.

Observe the attentiveness and effectiveness demonstrated by the project personnel at the site. The on-site review quite often provides a better basis for evaluation than the specifics of an individual's education or on-the-job experience as documented in personnel records. Include comments on the attentiveness and effectiveness of the project personnel in the report. Adequate and assertive responses to questions are good indications of proper experience. Comment on education and experience data only when it appears that certain individuals are not adequately performing their duties and their performance is believed to result from lack of training and experience.

Adequacy of Delegated Authority

Evaluate the extent of the authority that has been delegated to project engineering personnel; verify that delegation of authority is adequate to permit conducting the work effectively. Ascertain whether inspectors and other engineering personnel below the level of the project engineer have been given sufficient instruction to have adequate understanding of their authority and responsibilities. Verify that project personnel understand and have an appropriate number of contract documents and other guidance material.

Preconstruction Conference

Determine if a preconstruction conference was held and, if so, who participated, whether an agenda was used, and if minutes were developed. Read the minutes to familiarize yourself with the project. Confirm that issues raised during the preconstruction conference have been properly resolved.

Report Summary, Recommendations, and Followup

Prepare a report of each IID and distribute in accordance with division office procedures. Refer to example forms for inspections as shown in Appendix G and on the FHWA headquarters Construction Web page: https://www.fhwa.dot.gov/construction/.

Within the report, identify the project, location, contractor, and project engineer; provide a general description of the work and a more detailed description of the particular phases of work involved in the inspection. Use inspection questionnaires based on the specific contract requirements and STA procedures.

Discuss deficiencies, irregularities, and concerns, along with exemplary work, in adequate detail to provide an understanding of the issue. Emphasize recurring concerns by using photographs, charts, and tabulations.

Avoid overemphasizing deviations from desirable procedures that are trivial in character or that do not have significant effect on the value or serviceability of the completed project nor on the effectiveness of the control over the work.

Include a concise summary statement of the important findings and recommendations for corrective actions if any are required. Whenever improvements are necessary or desirable, ensure that there is appropriate followup to verify that corrective action is taken and that the desired results are accomplished. In some instances, conditions and practices found on one project will indicate the need for checking whether similar conditions and practices exist throughout the State or jurisdictional subdivision thereof or on other projects where the same engineers and contractors are involved. Establish reasonable time frames for the resolution of issues.

Document followup in subsequent reports. When the conditions and actions are limited to one project, report further developments in either special followup reports or in subsequent regular intermediate or final inspection reports. When the conditions are found to exist generally or on a number of projects and the corrective actions have corresponding application, report specific followup actions in special reports. Cross-reference the original IID report and provide the same distribution as the original IID report.

Consider withholding further Federal funds from the project or projects as appropriate when the necessary improvements are not accomplished.

Ensure that the original of the report and all significant work papers are made a part of the division's project files.

Project Supervision and Control

Preconstruction Conferences

Most STAs require that a preconstruction conference be held prior to work commencing. All parties involved in the contract-and representatives from other contracts that could affect the project-should attend. Minutes from the conference should have been prepared and should document, as a minimum:

  • Railroad or utility adjustments
  • Public relations and the interests of abutting property owners
  • Contractor's work plan and schedule of operations
  • Contractor's backup plan for major stages of construction
  • Specific contract requirements
  • Safety measures, traffic management, and traffic control considerations
  • Environmental commitments
    • Erosion and sedimentation control
    • Dust abatement
    • Noise mitigation
  • Rights-of-way available for use by the contractor
  • Time limits and performance of operations including materials delivery considerations
  • Construction time and cost control
  • Emergency response to incidents

Attend these meetings on full involvement projects, if possible, or review the minutes during inspection trips.

Project Diary, Inspectors' Daily Reports, and Orders to Contractor

Examine the project diary, inspectors' daily reports, progress charts, and other data compiled in the field office to facilitate job control. Diaries and inspectors' daily reports are very important documents and must be complete yet concise, accurate, and factual to be effective. Ensure that diary entries are signed and dated and have been reviewed by the engineer in charge. Verify that discussions with the contractor are confirmed in writing and are made a part of the official project file. Review and confirm that there is a complete audit trail for work performed, measured, and paid.


Ensure the STA's subcontracting procedures on NHS projects meet the requirements set forth in 23 CFR 635.116. State procedures should be followed for non-NHS projects. Review and comment on the extent of subcontracted work. Verify that each subcontract has been approved by the State or that an FHWA-approved contractor certification process is being followed. Review copies of the subcontracts to see that they comply with the contract and contain Form FHWA 1273. Assess the prime contractor's general administration of subcontract work. Ensure that Disadvantaged Business Enterprise (DBE) subcontractors are performing a com-mercially useful function.

Engineering Surveys

Evaluate the adequacy of the project base control and subsequent construction survey procedures. When the staking of part or all of the work is by the contractor or a consultant, it is recommended that there be adequate verification checks by the STA to assure that the work is correct. If there are survey errors that have led to contract change orders, determine if FHWA participation is appropriate.

Examine a sample of survey notes covering slope staking for grading operations or layout for bridges and culvert construction to determine the degree of clarity and orderliness of procedures. Verify that checks have been made to avoid errors in layout.

Examine a sample of survey notes used for measurement of pay quantities, such as cross-sections, to determine accuracy and correctness of procedures used.

Ensure that project control staking is adequately protected during construction operations.

Quality Assurance

Evaluate the project's quality control and acceptance procedures, personnel, and facilities. If required by the contract, the contractor must develop a quality control plan to define sampling, testing, and inspection procedures to be followed. Refer to Appendix B and Appendix E for samples of quality control plan requirements and actual project-specific plans. The contract will also define required accept-ance testing, whether by the STA or by the contractor with STA verification. Ensure that adequate quality control and acceptance is being exercised and that materials incorporated in the work are in substantial conformity with the contract.

Project Laboratory

Verify that contractor-furnished laboratories meet contract requirements. Ensure that scales and measuring devices have current certifications for accuracy. Typical equipment requirements for various construction operations are as follows:

  1. Grading: sieves, scales, liquid limit devices, compaction test equipment, field density equipment, hot plates or field stove, oven, sampling equipment, sample containers, and drying pans.
  2. Subbase and base course: sieves, sample splitters, scales, hot plates, devices for determination of moisture content and liquid limit, drying pans, and apparatus for making laboratory compaction tests and for determining in-place densities.
  3. Hot mix asphalt (HMA): thermometers, sieves, sample splitters, scales, hot plates or field stove, burn-off oven, equipment for taking samples from the pavement, and apparatus for determining pavement density and stability of the HMA mixture.
  4. Portland cement concrete: slump cone or other specified equipment for determining consistency of the mix, air meter, concrete cylinder or beam molds, sieves, sample splitters, scales, pans, stove or hot plate, and containers for determining unit weights.

Determine what method is used by the STA to "qualify" the laboratories used for NHS project testing as required by 23 CFR 637. If the IID permits review of the STA's central laboratory, verify that it has been accredited by the Accreditation Program of the American Association of State Highway and Transportation Officials (AASHTO) or a comparable laboratory accreditation program approved by FHWA (23 CFR 637). District laboratories may be accredited by the AASHTO Accreditation Program or a comparable laboratory accreditation program approved by FHWA or reviewed by the STA's central laboratory.

Materials Inspection Personnel

Identify the inspectors assigned to the particular phases of the work and discuss their responsibilities with them. Focus on these responsibilities:

  • Inspection duties
  • Field diary entries
  • Tests required and frequency
  • Test results and statistical summaries
  • Action on marginal or failing tests
  • Records forwarded to the project engineer
  • Inspectors' particular sampling and testing qualifications

Appraise the technical ability and effectiveness of the inspector and evaluate the adequacy of the control methods applied on the project. Observe the inspector's sampling and testing techniques to ensure that the specified procedures are being followed.

Test Reports

Check the project files to verify these testing conditions:

  • All materials are covered by adequate quality control and acceptance tests, and the frequency of sampling and testing is in accordance with the contract's schedule of test requirements.
  • The statistical method used to verify the contractor's test population has been validated by independent random STA tests.
  • Third-party independent assurance test results (split samples) compare favorably with project quality control and acceptance tests.

Report minimum and maximum test results and statistical summaries with appropriate remarks regarding the suitability of the material. Evaluate project office procedures for filing test reports, checks made to ensure that all necessary reports have been received, methods to readily identify unsatisfactory or borderline materials, and general house- keeping methods in the handling of the reports.

Ensure that any deviations from the specifications indicated by the test results are explained and that all corrective actions taken are documented. Comment on the disposition of all nonconforming materials received on the project. Verify the process for getting deviations listed in the project's final material certification on NHS projects (23 CFR 637.201).

Verify that certifications, inspections, and test reports on manufactured materials document conformity with the specification and that the test reports on file cover the materials actually delivered to the project. Determine whether certifications for iron and steel products conform to Buy America requirements.

Witness the sampling and testing of quality control and acceptance tests to the extent practical. Take independent measurements of width and depth of bases, surfaces, and other components of the construction, including structures, to validate that the project is being constructed in substantial compliance with the plans and specifications.

Measurement of Quantities

Ensure that the methods used in the measurement of quantities meet contract requirements (23 CFR 635.123).

Determine the frequency of contractor progress payments. Verify that the appropriate quantities of completed work are reported for progress payments. Comment on whether or not a new overall estimate is made for each progress estimate or if computed monthly work quantities are merely added on the estimate of work done during each succeeding period; the latter could result in cumulative errors of consequence. Check the quantity calculations for two or three major items and one or more minor items. Note significant digits. The validity of final estimates cannot be greater than the accuracy exercised in making the field measurements used in the computations. Careless field measurements are difficult to detect, but an examination of the field books will provide some indication as to the extent to which good survey and measurement practices are being followed. Identify in the report what bid items or stockpiled materials were reviewed, if properly identified, dates and personnel making the measurements, proper explanations and initials on corrections, and overall legibility.

At the final estimate stage, review final quantities in considerable detail on a few items. Note assumptions made, significant figures, accuracy observed, and amount of checking done. Indicate the extent of checks and reviews made beyond the project level, such as in the district and central offices. Where appropriate, evaluate the additional checks to assure the sufficiency of the validation.

The following is a summary of recommended inspection techniques:

  • Verify that the items reviewed were measured in the units called for in the contract provisions and that the methods of measurement prescribed in the contract and in authorized instructions were followed.
  • Examine project records to insure that all materials measured for payment were delivered and incorporated into the project or stockpiled for future incorporation.
  • When payment is based on weight or mass, verify the accuracy of the measurements; consider the calibration of scales, checking of truck tare weights, and weighing of haul loads.
  • Where payment is based on loads delivered to the project, either on a weight or volume basis, verify the procedures followed for assuring validity in receipt of haul tickets. Discuss the procedures in effect with the project personnel. Focus on practical concepts (falsified haul tickets can be determined by analyzing project records and determining that the number of trips reported was impossible considering time and length of haul involved).
  • Where area methods of measurement are specified, make dimensional checks to the extent necessary to verify the actual work performed. Ensure that measurements were made at the proper time and prior to the subsequent placement of other courses of materials.
  • Where final quantities are determined by volume computations, verify the method of measurement and documentation of calculations.
Construction Changes and Extra Work

On full oversight projects, be aware of circumstances that required the changes in the plans and specifications. Comment on the need for the construction change and whether the revisions and additions are necessitated by conditions that could not be reasonably anticipated before the project was advertised for bids. Discuss weaknesses in the preparation of plans, specifications, and estimates, and other deficiencies of this nature to assist in funding determinations and in strengthening the State's design procedures and the FHWA's review procedures. Document the steps taken by the Construction Unit to inform Design of plans errors and omissions resulting in change orders.

Verify that proposed changes are consistent with sound design and construction practices and are compatible with the objectives sought in the original design and environmental clearances. Ensure that decisions are in the public interest, are not swayed by the expediency of construction convenience, and are not counter to the intended design concepts.

Support cost-effective changes that improve aesthetics, reduce overall construction costs, and improve the safety of the highway. Verify if project personnel take steps to incorporate these advantages into the project (e.g., an unexpected surplus of excavation becomes available that could be placed within an interchange loop or used to flatten embankment slopes, thus eliminating guardrail and increasing the safety features of the highway).

Become familiar with the Division/STA Stewardship Plan, the definition of major and minor changes, and the approval process on full oversight projects; refer to 23 CFR 635.102 and 23 CFR 635.120. Evaluate the reasonableness of unit prices, labor, overheads (field and unabsorbed home office), and rental rates established for items of work to be performed. Since the cost to process a change order is a direct project expense, consider the following "rules of thumb" when evaluating changes: obtain a better product at no increase in cost or time; obtain an equivalent product at a savings in cost or time; use a change when the product as designed can not be constructed at no fault of the contractor (differing site conditions, "acts of God," etc.).

Ensure that project personnel have evaluated and documented the effect of the contract change to the approved project schedule. Include the appropriate time extension on the change order; refer to 23 CFR 635.121.

Contract Time Charges, Time Extension, Liquidated Damages, and Cost Control

Verify that project personnel are assessing the correct time charges. Compare work completed, as noted in project diaries, to contract time charges. Evaluate the contractor's critical path method schedule to support time charges. Ensure that contractors are provided formal warning when work is behind schedule and that corrective actions are requested. Ensure that the correct liquidated damages are assessed on projects that exceed the allowable contract time; refer to 23 CFR 635.127.

Review contract expenditures and changes to ensure that the work is constructed in accord within the approved scope, cost, and termini.

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Updated: 06/27/2017
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