What is Retroreflection?
Retroreflection happens when a surface reflects a sizable portion of a directed beam of light back to the source of light.
Image, credited to 3M
According to 3M, "retroreflective is the property of an object or surface to reflect light back along or close along its incidental path, regardless of where the light is coming from (i.e. regardless of the entrance angle)."
Retroreflective materials and sheeting will appear far brighter for observers who are closest to the light source (i.e in your drivers seat). The surface's brightness solely depends on the intensity of the light source and the what the materials that the surface is made of.
Benefits of Retroreflection
Traffic signs convey very important information that is integral for traffic safety.
It can improve road safety
According to 3M, not long ago, Albuquerque NM upgraded its signs in sections across the city. These areas were upgraded with retroreflective sheeting that complied with ASTM D4956 Type XI. All of the other areas of the city were appointed as the control.
There was an overall decrease in night-time fatal injury crashes where the city upgraded to ASTM D456 Type XI-compliant retroreflective sign sheeting. There was not a shared decreased of night-time fatal injury crashes in the controlled segments.
It reduces time spent reading
Reading and comprehending signs can become more difficult when driving at night. This is why signs must be highly reflective, at greater distances, to give motorist ample time to read, comprehend, and react.
Researchers suggest that brighter signs allow drivers to obtain information quickly and/or more accurately. Such signs can help provide a more visible target for night-time drivers, especially when there are many other distractions on the road.
Types of Retroreflective Sheeting We Use
HIP Sheeting: (High Intensity Prismatic Grade Sheeting) 3M High Intensity Prismatic Reflective Sheeting Series 3930 is a non-metalized micro-prismatic lens reflective sheeting for production of reflective work zone signs. Durable, tough topcoat aids against scuffs and scratches. Meets ASTM D4956 Type III, IV. Performance warranted for up to 10 years.
VIP: (3M Diamond Grade VIP Reflective Sheeting) 3M Diamond Grade VIP Reflective Sheeting Series 3990 offers premium short distance sign brightness. Meets several top-level performance specifications. Ideal for urban street and intersection signage.
DG3: (3M Diamond Grade DG3 Reflective Sheeting) 3M Diamond Grade DG3 Reflective Sheeting Series 4000 offers superior reflectivity at short and long distances. This is one of the brightest and durable sheetings for cost-efficient guidance and lasts up to 12 years.
We use the above sheeting on our DOT signage which includes: extruded panel signs, increment panel signs, regulatory & warning sign, and our logo panel signs.
Read more on 3M's website about road safety.