HJL,
I wanted to make a comment about this great letter. I think it may bear mentioning that in an emergency situation the weak point in the fence is the concrete. Having watched one get hit and seen many more that were hit, I can say that the concrete set post will give way before the cable. This being said I can’t for sure say the best way to knock one over but bumper up to it at a 90 degree angle and the post should give way then the slack between the posts should allow you to drive over the cable. The saw would be the best, but if you can’t exit your vehicle for any reason, hitting a post or two once or twice should allow you to get to the other side. Like the writer said, it is illegal to tamper with them, so testing this out would not be recommended, but if all else fails… – J.