25 CFR § 170.455 - What other factors must influence project design?

---
identifier: "/us/cfr/t25/s170.455"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "25 CFR § 170.455 - What other factors must influence project design?"
title_number: 25
title_name: "Indians"
section_number: "170.455"
section_name: "What other factors must influence project design?"
chapter_name: "BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR"
subchapter_number: "H"
subchapter_name: "LAND AND WATER"
part_number: "170"
part_name: "TRIBAL TRANSPORTATION PROGRAM"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "Pub. L. 112-141, Pub. L. 114-94; 5 U.S.C. 2; 23 U.S.C. 201, 202; 25 U.S.C. 2, 9."
regulatory_source: "81 FR 78463, Nov. 7, 2016, unless otherwise noted."
cfr_part: "170"
---


# 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.