Only a fool would ride against oncoming traffic in a 55 mph zone, just from the buffeting effects alone. She places herself as a mile or so past Chambers Street heading west. That puts her still a mile and a half away from McBeth Road, her landmark for the BMW, which already had come through the curves east of McBeth. If everyone is heading west as she stated, she's already well behind the BMW at that point. Therefore, the cars had to be heading east for her letter to be even remotely accurate.