California Department of Transportation

Project Development Workflow Tasks (PDWT)

Part 3 - Identify Project Need and Project Initiation Document

II. Project Initiation Document

D. Analyze Alternatives (WBS 150.15) - Prepare and Obtain Approval for Design Exceptions (WBS 150.25.10)

P68. Obtain Federal Highway Administration (FHWA) Approval

The FHWA has delegated Caltrans the responsibility for complying with federal statutes and Executive Orders. This minimized FHWA involvement in project activities and other actions. However, there are several areas where FHWA has retained approval authority. Chapter 2, Section 7 of the PDPM discusses the roles and responsibility and level of oversight of FHWA

Mandatory Design Exceptions

Exceptions to the Mandatory Design Standards may also require approval by FHWA.. The Caltrans-only mandatory design standards are identified with an asterisk in Table 82.1(A) of the HDM. Formal FHWA approval is required for design exceptions to the 13 controlling criteria when the route, project type, and cost meet either of the following criteria:

  • New construction / reconstruction projects on the Interstate System,
  • Construction costs greater than $1 million.

Vertical Clearance on Defense rural and single interstate routes

FHWA design exception approval is required for any project that does not provide, upgrade (including RRR and CAPM projects) or maintain a minimum vertical clearance of 4.9 meters on the Department of Defense rural and single interstate routes (HDM 309.2). HDM Chapter 21.2 discusses the Department of Defense routes. Exceptions to this standard will be difficult to obtain, and will be subject to additional federal review.

Changes in access control to the Interstate System

Conceptual acceptance of a new or revised freeway interchange proposal is a determination of the proposal's adequacy in meeting the design, safety, and operational standards of the Department and the FHWA. The Project Study Report (PSR) is used to justify and document this determination for both the FHWA and the Department. A PID that is used to program only the capital outlay support costs does not have the level of detail necessary to obtain conceptual acceptance. Development of this information will be completed in the PA/ED phase. Both the PID and a Modified Access report shall be submitted to FHWA for conceptual acceptance.

If the project involves an Interstate highway, Conceptual Acceptance from the FHWA. is required for:

  • New interchanges.
  • Modifications to existing interchanges involving access control revisions for new ramps or the relocation or elimination of existing ramps.
  • Projects to increase mainline capacity when existing interchanges do not meet HDM interchange spacing requirements.

Special project features on the National Highway System

Approval of any special feature in a project on the National Highway System requires review and approval. The Federal Aid Program Guide (FAPG) G 6012.1 defines features that are considered as major or as unusual structure. Typically, this applies to tunnels, bridges, hydraulic structures, or geo-technical features.

Requests for FHWA acceptance should be made by letter, addressed to the FHWA Division Administrator, and signed by a District Division Chief or the District Director. A copy of the approved Fact Sheet must accompany requests for approval of exceptions to mandatory design standards.

Time Constraints

Preparation of a letter requesting FHWA approval can be accomplished in a few days; assuming advance discussion with the FHWA Transportation Engineer, and their prior review of the draft documents, the review and approval process may take a month or two. For new or revised interchanges, FHWA may need to perform its own operational analysis using the HCM 2000 method, which will require a couple of months, assuming adequate information is supplied to them.


PDPM, (Chapter 2, Section 7.Article 1, “Federal Highway Administration")

Design Memorandum, (3/30/00, “Vertical Clearance on the Rural and Single Interstate Routing System")

PDPM, (Chapter 21, Section 2, “Exceptions to Vertical Clearance on 42 000 km Priority Network Design")

Design Information Bulletin #77, (January 3, 1995, “Interchange Spacing")

PDPM, (Chapter 1, Section 4, Article 2, “Transportation Systems")

PDPM, (Chapter 27, Article 5, “Approval of New or Revised Interchanges")

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This page last updated November 20, 2010