Each hit on the TL means we are closer to it being broken. Simply put, a trend cannot go forever. EW theorists (Dave, where are you?) will tell you a trend has five legs. In a DOWN, it is one south, the 2nd north, 3rd south, 4th north, and the last south. The next hit on the TL means it gets taken out. After several attempts, price tends to go sideways, ala bungee jumping and ping pong. The GBP/JPY broke the weekly TL this week after several attempts. The TL got so wore out, it finally gave out.
This is the case for all S&R's. As a measure of equilibrium (ichi taught me a lot), once price has pulled away from the S or R far enough, then price gravitates back to it, but won't break it on the initial attempt, because it is fresh.
A look at the Bollinger Bands as an SD model can also point this out.
Like I always say, don't believe me. Just apply them from a theoretical point of view, then report the findings, especially if I'm wrong (heh heh).