(a) Changeable message signs may be double faced, back to back, or V-type signs.

Terms Used In Tennessee Code 54-21-119

  • Changeable message sign: means an outdoor advertising device that displays a series of messages at intervals by means of digital display or mechanical rotating panels. See Tennessee Code 54-21-102
  • Commissioner: means the commissioner of transportation or the commissioner's designee. See Tennessee Code 54-21-102
  • Department: means the department of transportation. See Tennessee Code 54-21-102
  • Digital display: means a type of changeable message sign that displays a series of messages at intervals through the electronic coding of lights or light emitting diodes or any other means that does not use or require mechanical rotating panels. See Tennessee Code 54-21-102
  • Erect: means to construct, build, raise, assemble, place, affix, attach, create, paint, draw, or in any other way bring into being or establish, but does not apply to changes of copy treatment on an existing outdoor advertising device. See Tennessee Code 54-21-102
  • Highway: includes public bridges and may be held equivalent to the words "county way" "county road" or "state road". See Tennessee Code 1-3-105
  • Interstate system: means that portion of the national system of interstate and defense highways, located within this state, as officially designated, or as may hereafter be designated, by the commissioner, and approved by the secretary of transportation of the United States, pursuant to title 23 of the United States Code. See Tennessee Code 54-21-102
  • Nonconforming: means an outdoor advertising device that does not conform to the zoning, size, lighting, or spacing criteria established by and in accordance with either the current agreement entered into between the commissioner and the secretary of transportation of the United States, or in accordance with the original agreement entered into on or about November 11, 1971, as authorized in §. See Tennessee Code 54-21-102
  • Person: means and includes an individual, a partnership, an association, a corporation, or other entity. See Tennessee Code 54-21-102
  • Sign: means an outdoor sign, light, display, device, figure, painting, drawing, message, placard, poster, billboard, or other thing which is designed, intended, or used to advertise or inform any part of the advertising or informative contents of which is visible from any place on the main traveled way of an interstate system or primary system. See Tennessee Code 54-21-102
  • State: when applied to the different parts of the United States, includes the District of Columbia and the several territories of the United States. See Tennessee Code 1-3-105
  • Traveled way: means the portion of a roadway for the movement of vehicles, exclusive of shoulders. See Tennessee Code 54-21-102
(b) Changeable message signs with a digital display that meet all other requirements pursuant to this chapter are permissible subject to the following restrictions:

(1) The message display time must remain static for a minimum of eight (8) seconds with a maximum change time of two (2) seconds;
(2) Video, continuous scrolling messages, and animation are prohibited; and
(3) The minimum spacing of the changeable message signs with a digital display facing the same direction of travel on the same side of the interstate system or controlled access highways is two thousand feet (2,000′); provided, however, that an outdoor advertising device that uses only a small digital display, not to exceed one hundred square feet (100 sq. ft.) in total area, within a larger non-digital sign face is not subject to the minimum spacing requirement established in this subdivision (b)(3), or to any application for a specific digital display permit or permit addendum as established in subsections (c) and (d), or to any fee for a permit addendum as established in § 54-21-104(b).
(c) A person shall not erect, operate, use, or maintain a changeable message sign with a digital display in a new location without first obtaining a permit and tag expressly authorizing a changeable message sign with a digital display, and annually renewing the permit and tag, as provided in § 54-21-104. The department shall not require any additional permit under this subsection (c) for an outdoor advertising device with a digital display lawfully permitted, erected, and in operation prior to June 22, 2020.
(d) A person shall not erect, operate, use, or maintain a changeable message sign with a digital display in place of or as an addition to any existing permitted outdoor advertising device without first obtaining, and annually renewing with the permit, an addendum to the permit expressly authorizing a changeable message sign with a digital display in that location as provided in § 54-21-104(b)(3).
(e) The commissioner shall under no circumstances permit or authorize any person to erect, operate, use, or maintain a changeable message sign of any type as a replacement for or as an addition to any nonconforming outdoor advertising device or in any nonconforming location.
(f) Notwithstanding any other law to the contrary, a person who is granted a permit or an addendum to a permit authorizing a changeable message sign with a digital display in accordance with subsection (c) or (d) has up to, but no more than, twelve (12) months after the date on which the permit or addendum is granted within which to erect and begin displaying an outdoor advertising message on the changeable message sign; provided, however, that prior to the expiration of this twelve-month period, and upon making application to the commissioner and paying an additional permit fee in the amount of two hundred dollars ($200), the permit holder may obtain an additional twelve (12) months within which to erect and begin displaying an outdoor advertising message on the changeable message sign. This additional two-hundred-dollar fee is separate from any annual permit renewal fee required under § 54-21-104. If the permitted or authorized changeable message sign with a digital display is not erected and displaying a message within the required time, or as extended, the permit or addendum to the permit will be revoked and the changeable message sign with the digital display must be removed by the applicant or subject to removal by the commissioner as provided in § 54-21-105.
(g) Any application for a permit or addendum for a digital display as described in this section may be made using the form for an application for permit for an outdoor advertising device existing on June 22, 2020, until a separate form is available.
(h)

(1) All changeable message signs installed on or after July 1, 2014, must come equipped with a light-sensing device that automatically adjusts the brightness in direct correlation with ambient light conditions.
(2) The brightness of light emitted from a changeable message sign must not exceed 0.3 foot candles over ambient light levels measured at a distance of one hundred fifty feet (150′) for those sign faces less than or equal to three hundred square feet (300 sq. ft.), measured at a distance of two hundred feet (200′) for those sign faces greater than three hundred square feet (300 sq. ft.) but less than or equal to three hundred eighty-five square feet (385 sq. ft.), measured at a distance of two hundred fifty feet (250′) for those sign faces greater than three hundred eighty-five square feet (385 sq. ft.) and less than or equal to six hundred eighty square feet (680 sq. ft.), measured at a distance of three hundred fifty feet (350′) for those sign faces greater than six hundred eighty square feet (680 sq. ft.), or subject to the measuring criteria in the applicable table set forth in subdivision (h)(4).
(3) Any measurements required pursuant to this subsection (h) must be taken from a point within the highway right-of-way at a safe distance from the edge of the traveled way, at a height above the roadway that approximates a motorist’s line of sight, and as close to perpendicular to the face of the changeable message sign as practical. If perpendicular measurement is not practical, valid measurements may be taken at an angle up to forty-five (45) degrees from the center point of the sign face. If measurement shows a level above that prescribed in subdivision (h)(4), the exact calculations must be provided to the sign permit holder.
(4) In the event it is found not to be practical to measure a changeable message sign at the distances prescribed in subdivision (h)(2), a measurer may opt to measure the sign at any of the alternative measuring distances described in the applicable table set forth in this subdivision (h)(4). In the event the sign measurer chooses to measure the sign using an alternative measuring distance, the prescribed foot candle level above ambient light must not exceed the prescribed level, to be determined based on the alternative measuring distances set forth in the tables in subdivisions (h)(4)(A), (B), (C), and (D), as applicable. For any measuring distance between the alternative measuring distances set forth in the following tables, the prescribed foot candle level above ambient light must not exceed the interpolated level derived from the following formula:

[l2 = (D2<2>/D1<2>) x l1]

Where l1 = the prescribed foot candle level above ambient light for the measuring distance listed in the tables, l2 = the derived foot candle level above ambient light for the desired measuring distance, D1 = the desired measuring distance in feet, and D2 = the alternative measuring distance in feet listed in the tables, as follows:

(A) For changeable message signs less than or equal to three hundred square feet (300 sq. ft.):

Alternative Measuring Distance:

Prescribed Foot Candle Level:

100

0.68

125

0.43

150

0.3

200

0.17

250

0.11

275

0.09

300

0.08

325

0.06

350

0.06

400

0.04
(B) For changeable message signs greater than three hundred square feet (300 sq. ft.) but less than or equal to three hundred eighty-five square feet (385 sq. ft.):

Alternative Measuring Distance:

Prescribed Foot Candle Level:

100

1.2

125

0.77

150

0.53

200

0.3

250

0.19

275

0.16

300

0.13

325

0.11

350

0.1

400

0.08
(C) For changeable message signs greater than three hundred eighty-five square feet (385 sq. ft.) but less than or equal to six hundred eighty square feet (680 sq. ft.):

Alternative Measuring Distance:

Prescribed Foot Candle Level:

100

1.88

125

1.2

150

0.83

200

0.47

250

0.3

275

0.25

300

0.21

325

0.18

350

0.15

400

0.12
(D) For changeable message signs greater than six hundred eighty square feet (680 sq. ft.):

Alternative Measuring Distance:

Prescribed Foot Candle Level:

100

3.675

125

2.35

150

1.63

200

0.92

250

0.59

275

0.49

300

0.41

325

0.35

350

0.3

400

0.23

425

0.2

450

0.18

500

0.15
(5) This subsection (h) applies to all changeable message signs located in this state operated pursuant to a permit issued by the commissioner.
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