If you are the engineer, you may be reassuring yourself in the dream state that you are in control of a specific situation, or your life in general. Freud said that the train is usually a phallic symbol, and that a train going through a tunnel represents intercourse. Freud also said that there are other possibilities to this symbol.
For example if you missed the train in your dream, you may be fearful of missing important opportunities.
What Does Train Mean In Dream?