What is the reasonableness standard in the context of a judicial review of an administrative driving prohibition?

Since Dunsmuir was decided, the courts have applied the reasonableness standard in the context of administrative driving prohibition judicial reviews. In particular, the courts have emphasized an important qualification to the deferential reasonableness standard, namely that the court is entitled to interfere if the route to a decision is demonstrably unreasonable, even where the ultimate findings might be capable of support by the record: see McConachie v. British Columbia (Superintendent of Motor Vehicles), 2014 BCSC 2009 at paras. 19 to 24.

In Kenyon v. British Columbia (Superintendent of Motor Vehicles), 2015 BCCA 485, Tysoe J.A. explained the application of the reasonableness standard. In particular, for the court, at para. 53, he held that: