A digital display needs two descriptions: what is being installed, and how it will operate. A cabinet drawing alone does not explain whether messages scroll, how long each image stays still, or what happens when the light sensor fails. Build those answers into the permit package before ordering the display.
This checklist compares a proposal with the requirements for a particular site. It does not estimate how many governments allow digital signs or supply a nationwide default setting.
Start with the sign and the site
The International Sign Association describes an electronic message center as a display whose words or images can change electronically. That industry description helps identify the equipment; it does not decide its legal classification.
- Physical form: show the complete wall-mounted or freestanding structure as well as the electronic portion.
- Message relationship: describe whether the display advertises an activity at the site or elsewhere. Ask which definition applies.
- Location: identify the parcel, zoning district, overlays, road frontage, and nearby residential property.
- Project type: distinguish a new structure, replacement face, and conversion of a static sign. Ask whether the existing approval covers the proposed change.
Give the reviewer an operating schedule
| Question | What to specify |
|---|---|
| How long is one message stationary? | The hold or dwell time for each complete image. |
| What happens between images? | The transition effect and its duration, separately from hold time. |
| Does anything move within an image? | Identify scrolling, animation, video, flashing, or other movement. |
| When does it operate? | Operating hours and scheduled shutdown or dimming. |
| How is output controlled? | Sensor location, dimming settings, test method, and controller access. |
| What happens after a fault? | Proposed behavior after sensor, communication, or controller failure. |
Keep the specification consistent with the demonstration video and programmed controller. A still rendering cannot show whether the display animates. See the hold-time and transition guide.
Match the brightness test to the requirement
Luminance describes light from a surface in a given direction; illuminance describes light arriving at a surface. NIST explains these separate quantities. A display-face measurement and a reading near neighboring property answer different questions.
Request the unit, measuring location, viewing angle, test image, ambient conditions, and day/night procedure. A controller percentage is not itself a measured light level. Use the brightness measurement guide to prepare the test record.
Resolve missing answers before purchase
If a search for electronic message centers returns nothing, check definitions, general sign provisions, illumination rules, and prohibited-sign provisions. An empty search result or report field is not permission. Ask the reviewing office for a written classification of the proposed equipment and operation.
For off-premise advertising along a highway, identify the state outdoor-advertising office as well. FHWA maintains separate outdoor-advertising guidance, including off-premise changeable message signs; that guidance is not a permit for an on-premise business display.
Finish with one schedule tying each operating setting to its applicable source or written approval. Mark unresolved items “confirmation needed” instead of borrowing settings from a previous job.