How to delete double lines on top of each other?

Is there a easy/batch way of deleting overlapping lines? 

If I have 2 (or more) lines that are equal in length and direction, so as to appear as only one line, then how do I get rid of all the double lines except for the original line?

I know the easy way is to just select the top line and hitting "delete", but that is not an option if I have 10+ lines in a drawing of over 50+ lines. Too time consuming every single time double lines are produced.