To see a line in your dream symbolises duality, limits, boundaries and rules. It also relates to movement or non-movement. To dream that you are crossing a line suggests that you are overstepping your boundaries or that you are moving beyond the limits in some area of your life.
To see a line of people or objects indicates that you need to be more aware of some situation or relationship.
To dream that you are standing in line represents your need for patience. You need to learn to wait for something and not always have it right away.