回複：Safe is better than Sorry

In my view, all actions permitted by the rules are considered as safe. As far as driving is concerned, over-safe sometimes can become a safety hazard. For example, when most people have the tendency of moving to the intersection for a possible left-turn, there is one car that is refused to move. You can imagine what will be happening. As pointed out by hmo, there is a mathematical chance that you can never get a chance to turn left if you insist to wait behind the line. On the other hand, as stated by xxhhwxc, before we move over the white line, we need to make sure that the intended left-direction has enough space.