During my early years of learning photography, I used to loiter in overpass bridges during night to practice. One of my favorite subjects are passing vehicles because I love the challenge of capturing its movement. I recorded the proper speed of the shutter in order to get the effect that I want.
Nowadays, I still used to do this just to capture the feeling of satisfaction that I had back then. The learning doesn't stop in photography it continues no matter how much you are familiar with the camera and the techniques. Its a craft in which one should always practice and practice until you surpass your expectation.