The hierarchy hazard controls is a de facto standard for determining which measures to take in the presence of risks. The principles can be (and I would argue that they should be) applied to road safety.
From the most effective to the least effective measure, we have:
Elimination: Avoid road trips. Of course it is rarely possible.
Substitution: Replace dangerous vehicles with non-hazardous vehicles. That is, cars should be limited
Engineering controls: people are isolated from risks: cycle paths, sidewalks everywhere, speed bumps, raised crossings, narrowing of the roads
Administrative controls: speed limits, 30 km/h cities, speed cameras, training courses.
And last and most definitely least:
personal protective equipment: they are the least effective, to be used only if there is no possibility of applying other measures: helmets.
Those who push for certain measures do not understand anything about safety, and thus would start from the bottom of the hierarchy.