The engineering community has known standards and methodologies for defining performance and impact. Using these methods to specify access allows the user to reasonably predict what is going to happen on site: the deflection underneath the mat, the percentage of allowable stress on the mat, the average bearing pressure on the subgrade beneath the mat, and more when under load. This information takes the guessing out of the design and can be compared to stated expectations to design a system that is performance rated and least environmentally damaging.