Many feng shui practices say that a house which sits at the end of T junction is not auspicious. From the feng shui point of view, when a road points directly to the front door of your house, the flow of energy could be too fast, thus it is not ideal. Psychologically, the image of a car driving toward your doorway is not the most pleasant feeling. If this is a concern for you, the best remedy, without moving the door, is planting a tree to block the view of just the street, not the general open view. Doing so, you will not immediately see cars coming and going when you exit your house. But do make sure the tree is not too close to the door, such that it blocks the view and normal energy flow to the house.
However, there are many kinds of so-called T junctions. Often it might not necessarily be a concern to you. The scale of impact has a lot to do with the length, width and straightness of street. If the street is long, wide and very straight, it will have a more negative impact. It also has to do with if the street is on a flat open field or has houses along both sides of the street. In general, a street with tall houses along both sides of the street creates a tunnel effect; the flow of energy tends to be much more violent, thus has a more negative impact.
Often you might not be able to tell if your particular situation could affect you. Here are some suggestions. If you have lived in the house for 2-3 years, and everything is just fine, your concern might be unfounded. If however, you experienced issues happening in your family and cannot find an obvious reason, this may be one concern. Those in other situations as, “But I am just considering if I should buy the house” here’s what you can do. Stand in front of the door, and pay attention to the street to see if the passing cars bother you or not, then turn to your feelings for decision making.