The use of left over 2" insulation is the key to this scene. I wanted to have an elevated track going up to a city scene and had to think of many real scenes, most of which brought my mind to what grade to use, this was a dilema as most are 2% or less and mine is certainly way beyond that but the important things are left up to the imagination and not always practicality, so it is a steep climb. Besides the incline the city base serves as a long tunnel with a removable portion of the city block!