The next project one of our club members is working on is for trains to cross over/under each other. This requires a fairly high graded slope to achieve to keep the distances reasonable. That in turn requires the trains to be smaller and lighter to make the grade. For this standard, the decision was made to go up 3 plates every 16 studs. This is actually 3 times greater than what is “desirable” for grade, but it’s required to keep the layouts in a reasonable size.