Boyce (D) was indicted on three counts of carrying carbon bisulphide through the Holland Tunnel. On the third trip, a load exploded in the tunnel, and about sixty persons were injured. The indictment alleged that there were other available and more practicable routes for the transportation of such a dangerous cargo. The indictment also alleged that D knew it was a violation of the ICC regulations to make such a shipment through the tunnel. The District Court dismissed the counts of the indictment based on the regulation in question holding that it was invalid; the words 'so far as practicable, and, where feasible' as so vague and indefinite as to make the standard of guilt conjectural. The Court of Appeals reversed.