I disagree that the cables are a failure. As someone from ODOT said, even concrete barriers are not guaranteed to stop a semi. You have to rely on drivers paying attention to some extent, and as was mentioned earlier, people will die on the highway, its a risk you take. With them saying that they KNOW of 400 hits on the cable barriers, how many occurred that they didn't know about, I'd say that they have done at least some good. You definately cannot say they are totally useless.