The train symbolizes your life. Large, important, full of people/situations. It also represents communication. It gets you to and from places where you may interact with different people. It represents your involvement with society. You said it was traveling at a smooth speed, yet you saw only a blur outside. Perhaps, the world/time is moving so fast you feel like you can't keep up, not that you want to since you are comfortable in your own speed.
The people on the train represent strangers, family, friends in your life AS WELL as obstacles/situations that have recently happened in your life. These people are traveling with you (kind of like luggage) and they are always present because these are things/problems/rewards in your life that you are dealing with right now.
The train being in the road full of traffic means that maybe something new just came into your life that may be a bit odd or weird to get used to OR it could mean that you are comfortable in your smooth, easygoing life even if everything outside is wild and crazy and out of order. But in your subconcious you are thinking that maybe if you don't stay on your normal course and you start taking risks, then you or someone you know might get hurt in the end. Then again it could mean that someone wild and crazy has come into your life and you think one of you will get hurt because of some situation you can't control.
Perhaps, the fact that you keep having the dream over and over means you have rituals that you often follow? Maybe you make the same mistakes over and over? Or maybe it means that you are not in a changing situation. You feel restless like you are not going anywhere.
The destination may be a conflict between where you are and where you want to be OR or it may simply be where you are headed in your life and you worrying if you'll ever get there.
Try to stay on the train and see where you end up before waking up. Get a good look at the strangers faces. Are they happy or sad? Do they all look alike? Ask someone where you are headed. Do they listen to you? Do they answer you?
Being that it was a train and not a bus or a plane or a car, this means that you are traveling on a certain 'track' and you are maybe playing it safe. Maybe you are afraid that the train will jump the track and you'll be thrown off-course and into chaos. Maybe you WANT to be off track and into chaos but are afraid of the consequences.
Well thats my take. I saw this while searching for something. You can interpret dreams so many ways.
