23 CFR § 661.31 - Do TTF bridge projects have to be listed on an approved TTP TIP?

---
identifier: "/us/cfr/t23/s661.31"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "23 CFR § 661.31 - Do TTF bridge projects have to be listed on an approved TTP TIP?"
title_number: 23
title_name: "Highways"
section_number: "661.31"
section_name: "Do TTF bridge projects have to be listed on an approved TTP TIP?"
chapter_name: "FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "G"
subchapter_name: "ENGINEERING AND TRAFFIC OPERATIONS"
part_number: "661"
part_name: "TRIBAL TRANSPORTATION FACILITY BRIDGE PROGRAM (TTFBP)"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "23 U.S.C. 120(j) and (k), 202, and 315; 49 CFR 1.81, 1.84, 1.85; 23 CFR part 490, subpart D."
regulatory_source: "89 FR 57082, July 12, 2024, unless otherwise noted."
cfr_part: "661"
---


# 661.31 Do TTF bridge projects have to be listed on an approved TTP TIP?

Yes. All TTF bridge projects must be listed on an approved FHWA TTP TIP. TTF bridge projects included in the TTP TIP that are not fiscally constrained may still be included as a list of projects dependent upon the availability of additional resources, also known as an “illustrative list”.