80% of the crashes that result in a fatality or a traumatic injury are on arterials and collectors, which essentially are our strobes. These are really dangerous environments and everybody can feel them when they're in that. So why are there so many strobes in the US? What makes it happen here more than anywhere else? Well, Chuck says that it has to do with the history of development in this country and how we came to be a country with a lot of sprawl.