New Regional Materials Distance

(Distance by rail/3) + (Distance by inland waterway/2) + (Distance by sea/15) + (Distance by all other means). The sea distance converts to 7,500 miles. This is 30% of the circumference of the earth. Is this transportation actual miles traveled? It will be difficult to get this data from shippers and suppliers. Or, is this still a straight line calculation. What if the ship travels north and rail travels east, and a "truck" travels south? Would each separate path be calculated and added together? Unfortunately, these changes requires an addendum to the Reference Guide. Preferable a v3 book with tracked changes. Preferable provided free of charge to those that already own an earlier, out-dated, version.