The sad thing is, even if it led to a net increase in death and injury due to the causes you described, the traffic regulators would likely still see it as a ga

The sad thing is, even if it led to a net increase in death and injury due to the causes you described, the traffic regulators would likely still see it as a gain, because it would reduce the number of "traffic deaths". (Even if it lead to a larger increase in "crime deaths" and/or "medical trauma deaths".) It's another case of being careful what metrics you use, and what you optimize for.