If instead human values were prioritized over the values of the engineer, this entire line of thinking would be turned around. We want humans to be safe, ergo the crossing signal sequence must be short, therefore the traffic volume on this street must be reduced. This is perfectly acceptable reasoning, yet it is not presented as an option by the engineer to the elected officials. It is their choice, but the framing of the decision by Cignoli robs Springfield's elected leadership of their agency.
