23 U.S.C. § 111 — Agreements relating to use of and access to rights-of-way—Interstate System

(a) In general. Every agreement between the Secretary of Transportation and a State's transportation department, for building an Interstate System project, must include two promises from the State. First, the State won't add any new points where vehicles can get on or off the highway beyond what the Secretary already approved in the project plans, unless the Secretary approves the addition first. Second, the State won't let gas stations or other businesses that serve vehicle users be built on the Interstate's right-of-way, and won't redraw the right-of-way's boundary just to make room for one. Agreements can still let a State use the space above or below the highway's roadway — for example, building over or under it — as long as that use doesn't hurt the highway's safety or full use, doesn't require or allow cars to drive onto that space directly from the highway, and doesn't get in the way of traffic. This section also protects certain existing businesses: if a vehicle-service business already existed before January 1, 1960, is owned by a State, and is run by the State (itself or through a concessionaire), it does not have to be shut down or removed just because its road later became part of the Interstate System — as long as its entrances and exits meet the usual standards for that kind of highway. (b) Rest areas. Even though subsection (a) restricts roadside businesses, the Secretary must let a State build, run, and maintain rest areas along its Interstate highways. Inside those rest areas, the State can allow some limited commercial activity, but only for people already using the rest area: advertising and media displays (shown only inside a rest-area building and not readable from the highway), items promoting state tourism (like books, DVDs, or other media), tickets to the state's historical or tourism events, travel information such as maps and hotel coupon booklets, and lottery machines (with priority given to blind vendors, as described in subsection (c)). A State may let a private company run these commercial activities. Any money the rest area earns this way must go toward the cost of acquiring, building, running, and maintaining the State's rest areas — not other purposes. (c) Vending machines. Despite subsection (a), a State may place vending machines in rest areas, recreation areas, and safety rest areas on Interstate rights-of-way. These machines can sell only the food, drinks, and other items the State's transportation department decides are appropriate, and only the State itself may operate them. When deciding which vending machines to place, the State must give priority to machines run through the state agency set up under the Randolph-Sheppard Act, which gives blind vendors priority for this kind of work. The costs of installing, running, and maintaining these vending machines cannot be paid for with federal highway funds under this title. (d) Motorist call boxes. Despite subsection (a), a State may put emergency call boxes along National Highway System rights-of-way, and those call boxes may display who they belong to and who sponsors them. Any sponsor logo must be approved by the highway agency in charge of that road. A logo on the call box itself can be no bigger than the box, and no larger than 12 by 18 inches overall. A logo on a separate identification sign attached to the call box's post can be up to 12 by 30 inches. Logo-bearing signs can't be placed closer together than once every 5 miles. Within each State, at least 20% of the call boxes with sponsor logos must sit on highways outside of cities with populations over 50,000. All call boxes, and their posts, foundations, and mountings, must follow the Manual on Uniform Traffic Control Devices, or any other rule the Secretary sets, to make sure they don't create a safety hazard for drivers. (e) Justification reports. Sometimes the Secretary asks for, or requires, a report justifying a new project that would add an access or exit point to the Interstate System — including new or changed interchanges connecting a freeway to a local road inside a transportation management area. When that happens, the Secretary has the option of letting the State's own transportation department approve that report, instead of reviewing and approving it at the federal level.