True, I did cherry-pick the data, but pedestrian/vehicle interactions are the most likely to occur in areas where the speed limit is lower.
i.e. Most 55mph roads do not have crosswalks at every corner and pedestrians using uncontrolled intersections. Most 25mph roads DO have crosswalks (marked or unmarked) at every corner, and intersections are likely to be uncontrolled for peds. In other words, I am much more worried about getting hit by someone doing 30 in a 25 zone than I am about someone doing 60 in a 55 if only because I rarely walk or cross on roads like that. I suspect that data extrapolates since pedestrian infrastructure tends to be densest in low speed areas.
In any case, the GP was arguing that 5mph was arguably inconsequential. The paper I linked shows that at almost any speed risk of death rises in a meaningful way every 5mph.
To put it all into perspective. Would you rather get hit by a car at 55mph or 60mph? Is the difference marginal if you have to make that choice?
I'd rather every crosswalk start a 5 sec timer and flash the lights, and then spikes come up that blow out the tires of any car that's going fast enough within proximity of someone crossing. Driving in the city for anything but uniquely dependant utilitarian purposes should be a relatively rare thing, and building cities in a way that prioritizes it is preposterous.
I think we need to be careful; we can always show a slower speed is safer. I'm hoping to see where the speed limit is x on a road designed for x and someone goes x+5, the marginal danger.
I expect most accidents don't fit this profile and let's say there were 50k traffic deaths in a year, 1k match this scenario and the marginal impact is something like 50. This is pure speculation.
(Strawman) We could clearly limit most traffic deaths by going 5mph at all times. We generally accept the risk of higher speeds.
i.e. Most 55mph roads do not have crosswalks at every corner and pedestrians using uncontrolled intersections. Most 25mph roads DO have crosswalks (marked or unmarked) at every corner, and intersections are likely to be uncontrolled for peds. In other words, I am much more worried about getting hit by someone doing 30 in a 25 zone than I am about someone doing 60 in a 55 if only because I rarely walk or cross on roads like that. I suspect that data extrapolates since pedestrian infrastructure tends to be densest in low speed areas.
In any case, the GP was arguing that 5mph was arguably inconsequential. The paper I linked shows that at almost any speed risk of death rises in a meaningful way every 5mph.
To put it all into perspective. Would you rather get hit by a car at 55mph or 60mph? Is the difference marginal if you have to make that choice?