(a) Highways or thoroughfares that are maintained through the use of state or federal funds, and that are not needed for essential commercial or defense traffic, shall be eligible for designation as scenic highways, with exceptions the general assembly may from time to time consider necessary by designation in § 54-17-114.

(b) The designation of additions to the scenic highway system shall conform to the following criteria:

(1) Highways designated as scenic highways shall be components of a comprehensive system as outlined by a statewide scenic highway plan;

(2) Scenic highways shall travel through scenic, historic, geologic and pastoral areas of the state;

(3) Highways should be designated to offer alternative travel routes to the high-speed, heavily traveled highways in the state;

(4) Designated highways shall provide the motorist with safe and relaxing routes of travel; and

(5) Scenic highways shall conform to an interconnected state scenic highway system, except in unusual situations whereby a highway is judged desirable for inclusion within the system because of unique scenic, historical, geologic or pastoral features.

(c) The commissioner of transportation shall, in accordance with the rules, regulations, policies and procedures of the state publications committee, prepare a comprehensive statewide scenic highway plan. In the preparation of this plan, the commissioner may consult as necessary with the department of environment and conservation, the department of agriculture, the department of economic and community development, the respective development districts across the state, and the Tennessee historical commission. The comprehensive plan shall include, but not be limited to, the following elements:

(1) The major routes of travel of tourists through the state so as to maximize the use of scenic highways by visitors in the state;

(2) The desirability of connecting components of the Tennessee outdoor recreation area system, prominent historic sites, major cities, federal recreation areas, scenic, geologic and pastoral areas, and other desirable areas by a scenic highway system;

(3) An interconnected system of scenic highways to enable the motorist to traverse the state of Tennessee on scenic roads;

(4) Certain theme scenic highways of historical significance that would be beneficial and educational for travel by the citizens of the state and its visitors;

(5) An administrative framework for marking and maintaining individual components of the Tennessee scenic highway system;

(6) A report on the fiscal impact of recommended highways, including funds necessary to initiate and maintain those highways;

(7) Recommended specific highways to be designated by the general assembly as scenic highways in compliance with § 54-17-104, and subdivisions (b)(1)-(4), unless the general assembly by act designates specific exceptions to the requirements; and

(8) A uniform program for signing, marking, and promoting the Tennessee scenic highway system.