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Experimental Features

As defined in the Federal-Aid Highway Program Manual (Vol. 6-4-2-4), an Experimental Feature Project is a federal-aid highway construction project incorporating one or more Experimental Features. Generally, an Experimental Feature is defined as a material, process, method, equipment item, traffic operational device, or other feature which: (1) has not yet been sufficiently tested under actual field and operational conditions to merit acceptance without reservations in normal highway construction; or (2) has been accepted, but needs to be compared with alternative acceptable features to determine relative merits and cost effectiveness. One or both of these criteria serve as the basis for whether or not the Experimental Feature is justified for inclusion into the ongoing States program, and can gain federal approval.

Construction Memorandum No. 00-2 “Construction Projects Incorporating Experimental Features” (Appendix 10A) provides additional information.

The objectives of the Federal Experimental Feature Program are: (1) to actively encourage state highway agencies to evaluate new or innovative technology, or alternatives to standard technology, under actual construction and operating conditions; and (2) to provide a mechanism for the widespread dissemination and application of the results of these evaluations.

An Experimental Feature may be initiated by a District, Central Office, or Local Agency. Experimental Features are generally included and approved in a project, before the project is advertised for bids. For an Experimental Feature to be authorized or approved for inclusion in a federal-aid project, an Experimental Feature Work Plan must be prepared and submitted to the Federal Highway Administration (FHWA) for approval. The Work Plan shall be submitted through the Central Bureau of Materials (CBM) prior to the submission of the Preliminary Studies and Engineering (PS&E). CBM will then forward the Work Plan to the FHWA with a formal request for approval of the Experimental Feature. The CBM acts as liaison in submitting Experimental Features, and insuring uniformity in reporting to FHWA. The submitting agency is responsible for meeting work and reporting requirements in the Work Plan. Existing policy permits the inclusion of Experimental Features in construction projects which are already in progress, by submitting a change order. In such cases, the preparation of an Experimental Feature Work Plan, as outlined below, will be required and must be submitted to the CBM for forwarding to FHWA.

The Work Plan shall contain or reflect the following significant items:

  • Objective - The objectives of the Experimental Feature in terms of the purpose, how the results might be utilized, the economic benefits (e.g. saving in time, money, and lives), and finally how the results of the experiment may be implemented and applied to other construction projects.
  • Supporting Research - Reference should be made to any specific research, past experience, reports, etc. on the subject, which supports the basic concept of the Experimental Feature being suggested.
  • Plan of Study and Evaluation - The plan of the study, as well as the evaluation process should be detailed.

A control section shall be provided in all approved Experimental Feature Projects, unless the nature of the experiment is such that a control section would serve no purpose.

  • Inspection and Reporting - This should include the frequency of inspections (at least once a year), and the reporting anticipated during and after construction.
  • Method of Construction - The methods or means of constructing the Experimental Feature, as well as the materials, process, technique, and/or equipment necessary to the project (which is a departure from normal construction procedures) should be discussed.
  • Estimated Cost - The estimated additional cost of the Experimental Feature should be defined on a per unit basis, if possible. Due to the experimental nature, higher costs are normally anticipated; but the Experimental Feature should not be excluded for that reason. Additional costs could include such things as personnel, test equipment, travel, and cost of producing a final report. These additional costs are borne by the originating agency.
  • Estimated Time to Complete Evaluation - The estimated time or duration necessary to complete all aspects of the evaluation should be defined in the initial Work Plan. Included should be estimated construction time, performance observation time frame, and final report completion date.
  • Attachments - Attachments could include responsible agency with contact information, supporting research, specifications, plan sheets, special provisions, etc.

Although assistance during the preparation of the Work Plan is available from the CBM, the responsibility of preparing the Work Plan, conducting the inspections, and writing the final report is with the initiating Bureau, District, or Local Agency.

Because even small changes in an Experimental Feature can jeopardize valid research results; all changes involving Experimental Features in a project must have prior FHWA approval, regardless of whether they are major or minor changes. The request for the change should state clearly what effect the proposed change is expected to have on the research, and be submitted to the CBM.

The CBM's Engineer of Technical and Products Studies will submit all required correspondence to FHWA. Appendix 10B is an example submittal letter containing the required information. It should be noted, that three copies of the Work Plan and any associated material; such as, plan sheets, section maps, special provision, etc. should be enclosed. Also note, the District who initiated the project or the District where the project is located is to be sent copies. A copy is also sent to the Project Development and Implementation Section Chief, in the Bureau of Design and Environment.


  • Initial Reporting - Once FHWA approval is received, the CMB will submit the initial FHWA Form 1461 to FHWA with copies going to the same people as noted in the Approval Submittal letter to FHWA.
  • Annual Reporting - FHWA requires that Form 1461 be prepared annually for each Experimental Feature, and be submitted to FHWA in October of each year by CBM's Engineer of Physical Research. The person or Bureau responsible for monitoring the Experimental Feature is expected to visually inspect the installation, prior to completion of the annual report. CBM’s Engineer of Technical and Product Studies coordinates the annual monitoring.
  • Special Reporting - Form 1461 will be used periodically to update the status if and when appropriate information of interest on the Experimental Feature develops.
  • Final Reporting - A Form 1461 shall be completed and submitted concurrently with the final report.

The initiating agency is responsible for completing the initial and final Forms 1461. The annual update is the responsibility of the District, Bureau, or Local Agency monitoring the project. All Form 1461 submittals to the FHWA are the responsibility of CBM’s Engineer of Technical and Product Studies.

The field testing and evaluation can range from very simple to complex, depending on the Experimental Feature and what exactly is being evaluated. A one-page Final Report may be sufficient for a simple item; such as, a bridge expansion joint. A more complex Experimental Feature; such as, an open-graded drainage base may require a more substantial report.

The Final Report should include or refer to the Work Plan, be specific as to the performance of the product, the ease of construction, and recommended use or non-use of the Experimental Feature.

The Final Report should be sent to CBM's Engineer of Technical and Products Studies, who will review it prior to submittal to the FHWA.