e-CFR Navigation Aids


Simple Search

Advanced Search

 — Boolean

 — Proximity


Search History

Search Tips


Latest Updates

User Info


Agency List

Incorporation By Reference

eCFR logo

Related Resources

Electronic Code of Federal Regulations

We invite you to try out our new beta eCFR site at https://ecfr.federalregister.gov. We have made big changes to make the eCFR easier to use. Be sure to leave feedback using the Feedback button on the bottom right of each page!

e-CFR data is current as of January 14, 2021

Title 25Chapter ISubchapter HPart 170Subpart D → Subject Group

Title 25: Indians
Subpart D—Planning, Design, and Construction of Tribal Transportation Program Facilities


§170.454   What design standards are used in the TTP?

(a) Depending on the nature of the project, Tribes must use appropriate design standards approved by FHWA. Appendix B to this subpart as well as the official Tribal Transportation Program Guide list the applicable design standards that can be used.

(b) All other design standards not listed in (a) must receive approval from FHWA.

§170.455   What other factors must influence project design?

The appropriate design standards must be applied to each construction project consistent with a minimum 20-year design life for highway projects and 75-year design life for highway bridges. The design of TTP projects must take into consideration:

(a) The existing and planned future use of the facility in a manner that is conducive to safety, durability, and economy of maintenance;

(b) The particular needs of each locality, and the environmental, scenic, historic, aesthetic, community, and other cultural values and mobility needs in a cost effective manner; and

(c) Access and accommodation for other modes of transportation.

§170.456   How can a Tribe request an exception from the design standards?

(a) A Tribe can request an exception from the required design standards from FHWA. The engineer of record (the State licensed civil engineer whose name and professional stamp appear on the PS&E or who is responsible for the overall project design) must submit written documentation with appropriate supporting data, sketches, details, and justification based on engineering analysis.

(b) FHWA can approve a project design that does not conform to the minimum criteria only after giving due consideration to all project conditions, such as:

(1) Maximum service and safety benefits for the dollar invested;

(2) Compatibility with adjacent features; and

(3) Probable time before reconstruction of the project due to changed conditions or transportation demands.

(c) FHWA has 30 days from receiving the request to approve or decline the exception.

§170.457   Can a Tribe appeal a denial?

Yes. Tribes may appeal the denial of a design exception to: FHWA Office of Federal Lands Highway, 1200 New Jersey Ave. SE., HFL-1, Washington, DC 20590. If FHWA denies a design exception, the Tribe may appeal the decision Office of the FHWA Administrator, 1200 New Jersey Ave. SE., HOA-1, Washington, DC 20590.

Need assistance?