One stat missing from the debate

I’ve been reading with some interest about the debate over changing the residential speed limit to 30 km/ h in Calgary. I keep seeing one statistic repeated: that the likelihood of being killed by a vehicle travelling 30 km/ h is vastly lower than being killed by one travelling 50 km/ h.

Laudable, then, this reduction. But how many pedestrian fatalities (50 across Alberta in 2016, according to your editorial of Sept. 6) occurred on the kind of residential roads that would be affected by this new speed limit and how many occurred on higher-speed roadways?

Just wondering and I suspect the answer would reveal a problem with the logic of the reduction. I’d be happy to be wrong and would then happily support the change.