I have found that Travel Assist doesn't like shadows unless you are in constant shadow or constant sunlight. I drive on a two lane road frequently that is lined on both sides by tall mostly pine trees. In the mornings it is the east side trees that cast a shadow across the road and the west side trees in late afternoons. If I am driving into only a couple of shadows on a sunny day no problem, the car handles it well. If it is an area where there is a constant in/out section of shadow and direct sun the Travel Assist loses it's mind. You might call this an area of strobe effect or maybe picket fencing. Travel Assist just can't handle it. This is a constant thing, not a one time glitch. I just don't use Travel Assist when in this situation.