Construction sites are some of the most dangerous places in the world.  Couple a job site with the general public and they’re disasters waiting to happen.  According to the American Road & Transportation Builders Association, 579 people were killed in highway work-zone related accidents in just 2013 alone.  Professor Tom Martin and Kristen Hines, engineers at Virginia Tech, hope to greatly reduce that number with their recent development of a smart safety vest that gives several seconds of warning to workers if danger is approaching.