Dive summary:
It seems reasonable that a worker wearing something that flashes at vehicle operators would be safer than one with a vest that only reflects the vehicles' lights, and an Englewood, Colo., company called GammaBrite has put that proposition into a vest by putting in flexible lights.
The lights are powered by a small battery that can be charged from a USB jack on a computer or in a vehicle, and a demonstration video on the company's website shows that the lights can flash or be solid.
The promotional video also says that a federal regulation taking effect at the end of 2013 requires any kind of worker, including police and firefighters, working on a federally funded road to be wearing some form of high-visibility vest.
From the article:
Flexible GammaBrite lights, sewn directly into the vest and controlled by a USB charged battery, provides better visibility for safer sites. ...