Section 170.421 - What is the Tribal Transportation Improvement Program (TTIP)?(a) The TTIP: (1) Is developed from and must be consistent with the Tribe's Tribal priority list or LRTP;(2) Is financially constrained for all identified funding sources;(3) Must identify (year by year) all TTP funded projects and activities that are expected to be carried out over the next four years as well as the projected costs and all other funding sources that are expected to be used on those projects. Although 23 U.S.C. 134(j)(1)(D) indicates a TIP must be updated once every four years, Tribes are encouraged to update the TTIP annually to best represent the plans of the Tribe;(4) Must identify all projects and activities that are funded through other Federal, State, county, and municipal transportation funds and are carried out by the Tribe in accordance with 23 U.S.C. 202(a)(9) ;(5) Must include public involvement;(6) Is reviewed and updated as necessary by the Tribal government;(7) Can be changed only by the Tribal government; and(8) After approval by the Tribal government, must be forwarded to BIA or FHWA by Tribal resolution or authorized governmental action certifying public involvement has occurred and requesting approval.(b) A copy of the FHWA-approved TTIP is returned to the Tribe and BIA. Although the FHWA-approved TTIP authorizes the Tribe to expend TTP funds for the projects and/or activities shown, it does not waive or modify other Federal, local, or financial statutory or regulatory requirements associated with the projects or activities.