I know we are not meant to read the linked reports, but females have not become the dominant gamer, even by the definition used in the linked PDF: Page 3: Gender of game players: 52% male, 48% female. Sorry.

There are many interconnected explanations why the collision rate is declining - but some of the main ones would be massively improved vehicle safety design and engineering, improved road planning and construction, legislation and enforcement around drink driving, speeding etc. and the fact that road safety is taken seriously by society as a whole. Though the gains in the reducing collision rates have largely been stagnant in the best counties for road safety in recent years, and has actually began to reverse in some cases. Perhaps that is the proliferation of phones? But as always correlation != causation.