Design Criteria

General
“Design criteria” is defined as those basic elements in Chapter 2 of TxDOT’s
Roadway Design Manual
(i.e. horizontal and vertical alignment, sight distance) and those elements that depend on scope of work and functional classification in Chapters 3-8 of the Roadway Design Manual (i.e. design speed, lane width, structure width). They include both the “controlling” and “non-controlling” criteria for which design exceptions, waivers and variances must be considered as listed in Chapter 1, Section 2 of TxDOT’s Roadway Design Manual.
Federal Requirements
  1. 23 CFR §625.3(a)(1)
    – Requires projects on the national highway system to be designed and constructed to FHWA-approved standards.
    23 CFR 625.3(d)
    advises that the standards are applicable regardless of the source of funds.
  2. 23 CFR §625.3(a)(2)
    – Requires federally funded projects not on the national highway system to be designed, constructed, operated and maintained in accordance with state laws, regulations, directives, safety standards, design standards and construction standards.
State Requirements
  1. 43 TAC §§5.59
    ,
    15.56
    ,
    26.33
    and
    27.56
    – Specifies that projects must be designed in accordance with TxDOT procedures, standards and guidelines. For regional mobility authority (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, RMA or regional tollway authority is required to meet state design criteria, unless TxDOT grants an exception.
Required Practices
In general, the LG must design roadway projects using the TxDOT manuals and other accepted guidelines or submit and obtain TxDOT pre-approval of alternate design standards. The
LGPM Guide
provides a more detailed discussion of the required practices and LG/TxDOT responsibilities for using acceptable design criteria.