I think this was at least part of the issue with Jersey Week last year. There were 9 and 10 crowd levels at points that week, with lots of 7-8 crowds and I think it took even Disney by surprise. One morning, BTMRR operated on only one side (so half capacity) for a very long time, even after the line had become long. Had both sides been operating sooner, waits would have been much more manageable. Some think that the hurricane rescheduling had a significant impact on crowds, time will tell whether that was a one-off occurrence or whether crowds are just really popular that week now, due to F&W, the races, decorations, awesome weather, beginning of the Christmas parties, low DVC points at that time, etc.