Exceptions to Design Criteria

General
Selection of design criteria is covered above. All reasonable effort must be made to produce a project meeting the established design criteria. However, there may be occasions when one or more design elements do not meet requirements. Exceptions may be granted as an engineering decision if properly documented, and supported.
There are three situations where formal approval must be given: design exceptions; design waivers; and design variances.
  1. Exceptions cover deviation from specific “controlling” criteria established by federal regulation.
  2. Waivers cover deviation from “non-controlling” criteria, those values listed as specific, numerical criteria but not one of the listed “controlling” criteria.
  3. Variances cover deviations from the Texas Accessibility Standards.
The Texas Department of Licensing and Regulation is the approval authority for variances. The approval authority for exceptions and waivers is established by policy and by agreement between the LG and TxDOT.
Federal Requirements
  1. 23 CFR §625.3(f)(2)
    – States that approval may be given on a project-by-project basis to designs not conforming to the minimum specified criteria. The determination may be made only after giving due consideration to all project conditions such as maximum service and safety benefits for the dollar invested, compatibility with adjacent sections of roadway and the probable time before reconstruction of the section due to increased traffic demands or changed conditions.
State Requirements
  1. 43 TAC §§5.59
    ,
    15.56
    ,
    26.33
    and
    27.56
    – Requires projects to be designed in accordance with TxDOT procedures, standards, manuals and guidelines. TxDOT may be requested to approve deviations from criteria for specific elements. For RMA, toll and pass-through financed projects, preliminary design information must be sent to TxDOT for review and approval when the design is approximately 30 percent complete.
  2. Texas Transportation Code §222.104
    – Allows TxDOT to enter into an agreement with public or private entities that provides for the payment of pass-through tolls for the design, development, financing, construction, maintenance or operation of a toll or non-toll facility on the state highway system. The agreement must provide that a municipality, county, regional mobility authority or regional tollway authority is required to meet state design criteria, unless TxDOT grants an exception.
Required Practices
The procedures for obtaining approval for exceptions, waivers or variances to the design criteria vary by type. The
LGPM Guide
provides the required practices and related LG and TxDOT responsibilities for design criteria exceptions.