"慢慢地换到左道" is "unsafe lane change"

If you change to a fast moving lane (normally, left lane), you should speed up. The other day, while forced to break really hard by somebody doing exactly the same as you did, I think, if I cannot stop completely and not sure whether my left lane is empty, it is morally right to hit the car changing into my lane than change to the left to involve an innocent driver.