The first thing would be a national strategy to get people on board and working together. I would definitely increase research funding. I am the co-principal investigator of one of the CIHR teams on child and youth injury prevention. Our approach to research is very integrated. We work with non-profit organizations--the four national NGOs--to move forward.
On the actual concrete things that I think you're looking at, I would lobby very hard for bicycle helmet laws that cover all ages across the country--so mandatory bicycle helmet legislation. I would insist that playgrounds meet the CSA standards, because falls are really important. One of the places children fall is on playgrounds. If they fall onto a surface that absorbs the shock they're much less likely to get injured.
I would have four-sided pool fencing for all residential pools so that children, especially toddlers, can't toddle out and drown in them. I would make a concerted effort to protect vulnerable road users, like bicyclists and pedestrians, by having designated lanes that can't be impinged upon by cars; and speed limits in residential neighbourhoods, particularly in school zones, that are enforced and that slow traffic down, so that what happened to Tyler doesn't happen.
Is that enough of a wish list? I could go on.