Landing the heavys on 4R has always been marginal during winter ops. Most of the modern twins make the high speed and the last part of the runway doesn't get used much. Then you show up in your B-747 have to roll to the end. Braking action is usually worse in that last few hundred feet and you have to make a hard left 90 to exit and tower is bugging you to hurry. It would be soooo easy to just slide off the end.