High Visibility Clothing standards
IHVCA Standard for Reflective Safety Clothing
Reflective safety clothing must be capable of visually signaling the user’s presence. The clothing shall be detectable both during the daylight conditions and at night under illumination by a vehicle’s head-lights in the critical detection distance.
Clothing in most colors is visible during daylight in the critical detection distance as specified in most highway design standards. But during nighttime, for roadways either illuminated by street light or vehicle head lights, the detective distance of dark clad clothing is far shorter than the required. Proper design of the retro-reflective clothing will enhance the safety of the user.
There are high visibility safety apparel standards such as ANSI/ISEA 107-207, covering occupational clothing in the U.S., and EN471, EN 1150 in EU. But these standards are either not covering sportswear/casualwear or are driven by the properties of certain products. In lieu of minimum safety requirements, those standard starts.
Due to the high visibility clothing standard is safety related; the specification must be established based on published science of safety and statics of field research. This standard is specified based on the minimum required luminance at the minimum required safety detection distance, in the observation angles resemble to drivers in different sizes of vehicles.
Over specifying the coefficient of retroreflection is detrimental to the public safety, because it reduces or eliminates other important factors such as the creation of comfort and appearance. On the other hand, those reflective clothing with reflectivity below the minimum requirements will mislead people into believing they are visible while not.
This standard is developed based on published science that it can serve as a tool for the user, designer and manufacture to evaluate the performance and safety effect of the reflective clothing they are dealing with.