To what extent is a State required to plan if there are only a few (or no) facilities having extremely hazardous substances present in excess of threshold planning quantities, but there is significant interstate transportation of these and other hazardous substances?

While Section 327 of Title III generally exempts the transportation of hazardous materials from coverage under most Title III reporting requirements, the law does require comprehensive emergency plans that address all hazardous materials and the potential for both fixed facility and transportation incidents (Section 303).  The list of extremely hazardous substances should provide a focus and a starting point for planning.  Therefore, the transportation routes and facilities with significant inventories of hazardous substances should be considered in any plan.  Finally, Section 301 includes transportation officials among those representatives who must participate in local planning committees.