- Factors that influence sign legibility include retroreflectivity, color, letter/number font, and location (e.g., roadside or overhead). Prismatic sheeting enhances sign retroreflectivity. Use of fluorescent colors increases sign visibility in daytime low-light conditions (i.e., dusk, dawn, fog).
- To improve sign legibility, fluorescent microprismatic sheeting with an orange background is a better option than high-intensity sheeting.
- Use a maximum legibility index of 40 ft of distance/in. of letter height. For older drivers, a more conservative value is 33 ft/in.
CONTACT:
Chris VanDyke
Research Scientist | Program Manager
chrisvandyke@uky.edu
