What is the defence of necessity in the context of an incident where a truck driver refused to wait for over an hour to get materials from a distribution depot?

In the alternative, counsel argues the defence of necessity and that the test set out in Perka v. R., 1984 CarswellBC 2518 (S.C.C.) has been met. There was imminent peril or danger to the public if the accused did not get the materials needed to cover the icy roads during the morning rush hour. He had no reasonable legal alternative but to attend to that depot. The depot in the city’s west end did not have the proper material and he did not have his supervisor’s permission to go there. The harm avoided was greater than the harm inflicted. The accused had advised the officer the reason he would not wait although it was a “testy” exchange.