As we’re about to observe National Work Zone Awareness Week and in light of a work zone crash last month in Maryland, in which 6 workers were killed, we're revisiting a discussion with TTI's Jerry Ullman, research engineer and highway work zone safety expert. The number of fatal crashes in America is up by about 7 percent over the past decade. But in roadway work zones, it’s up by more than 40 percent. Jerry discusses why those work zones are dangerous not only for those who work in them, but for those who navigate them as well.