The correct answer is 200 cd/m2, as it aligns with established guidelines and standards for the luminance of internally illuminated exterior signs during nighttime. The maximum luminance level is important to ensure that signs are bright enough to be legible from a reasonable distance while also preventing excessive glare that could cause discomfort or distraction to passersby.
This luminescence standard is often referenced in the context of promoting both safety and visual comfort in outdoor environments, adhering to best practices that balance visibility with minimal environmental impact. The 200 cd/m2 limit helps create an effective wayfinding tool without overwhelming the surrounding area with light, making it suitable for urban settings where light pollution and visual clutter might be a concern.
Maintaining such standards contributes to a more sustainable and visually appealing built environment, highlighting the importance of carefully considering all aspects of exterior signage, both for aesthetics and functionality.