25 C.F.R. § 170.120 – How can Tribes use Federal highway funds for toll and ferry facilities?

(a) A Tribe can use Federal-aid highway funds, including TTP funds, to study, design, construct, and operate toll highways, bridges, and tunnels, as well as ferry boats and ferry terminal facilities. The following table shows how a Tribe can initiate construction of these facilities.

To initiate construction of a . . .	A Tribe must . . .
(1) Toll highway, bridge, or tunnel	(i) Meet and follow the requirements in 23 U.S.C. 129; and (ii) If TTP funds are used, enter into an Agreement as defined in § 170.5.
(2) Ferry boat or ferry terminal	Meet and follow the requirements in 23 U.S.C. 129(c).

(b) A Tribe can use TTP funds to fund 100 percent of the conversion or construction of a toll facility.
(c) If a Tribe obtains non-TTP Federal funding for the conversion or construction of a toll facility, the Tribe may use TTP funds to satisfy any matching fund requirements.