Mesh Generated in a Straight Line

I would like to use a variation of objects I created as the base of a level. I want the parts to generate in a straight line, so the character can run forwards, and I also want the level to delete the objects when they are not seen behind the character, to reduce lag. (LIKE SUBWAY SURFERS, FOR EXAMPLE) (Forward scrolling game with random variations of user designed levels using more than one, or many objects.