O'Grady v. Sparling, S.C.R. 804, was a landmark Supreme Court of Canada decision on the constitutionality of overlapping federal and provincial laws. The Court held that there was no conflict between federal dangerous driving offences, which only prohibited "advertent" negligence and provincial careless driving offences, which included "inadvertent" negligence. The analysis used here was later to be known as the paramountcy doctrine.
Read more about O'Grady V. Sparling: Background, Opinion of The Court, Dissent