Not driving cars at all offers the lowest. There has to be a degree of nuance when evaluating this.

Ironically in my town, we did have a "string" (3 people in 5 years) of pedestrian fatalities. All of which took place downtown where people actually do drive 25.

Well its not a sure rule of thumb that lower speeds are safer. People die falling bad from standing too. But it sure as hell makes it a guarantee you kill someone if you hit them at that speed. Especially some of these newer suvs where the front end is effectively a wall at pedestrian height.