Well, it's a simplification of a very complex system. I can think of at least one intersection where even going 40mph in a 35 zone will at least double your ris

Well, it's a simplification of a very complex system. I can think of at least one intersection where even going 40mph in a 35 zone will at least double your risk of a crash. I can think of other situations, for example highway driving, where going 80mph in a 65mph zone probably has an only minor effect compared to going 65mph, and depending on traffic could be safer.