Since the information is liner (as in, very strong indication that I should first be looking on the left and make my way to the right), the legend should to be first. I was looking at the dots like, "wait? what are these? Where can I find the answer?"
Also, there really isn't any solid indication of increments. 8:47 to 8:58 is a tiny gap, but 9:16 to 9:26 is a huge gap. then 9:26 to 9:29 is a relatively large gap.
Also, I see that it starts at 8:31, but when does it end? I see information extending past the last time, 9:29.
What are the dots in the middle? After a lot of guess, and I'm still not sure if this is right I'm assuming it means people got on if they are above the line, and get off if they are below the line. if that's true, it's a huge leap of faith because the labels that say that couldn't be any further away from the line, or those dots. Also, there's no way to tell when the people got on or off. That's okay if you want it to be relative, but then you NEED to make a grid (even though invisible) to map out your units of time.
Also, I see the bus comes to an end, but I still see people on it (if I'm reading that right). What happens to them at the end of the line?
And one more thing. Where did the 9:16 old man show up from? I don't see an indicator that he got on. I'm starting to assume that this isn't the full bus route. Maybe you should invest a day in actually riding the bus from start to finish to get an all inclusive set of data.