It really helps to keep a journal. Write how far and speed for a particular route then don't monitor that route for a few weeks. Don't try for speed, but you will be surprised that you can get to the top of the hill and shave off seconds or minutes. If you don't keep a log, you can get discouraged because you will always find a hill, or headwind or heavy legg day that will make you feel like you are not progressing. I don't record too much info, just at the beginning of the spring, I'll time a couple hills, and what was my lowest speed. In midseason and by fall there is usually an increase. As an example, I used to ride a lot faster, but now I commute and am tired/sleepy and sometimes I can barely make it home. Yet this is an easy route. When I ride on the weekend, I feel so refreshed and am much faster. If I only looked at the daily speed, I would think I was declining.