There should be no such thing as a routine traffic stop. That kind of adversarial police interaction should NOT be happening to citizens behaving normally. It should be reserved only for people behaving in a truly deviant way, which modest speeding is not. Normalizing this kind of interaction is part of what it means to be in a police state.
You can automate highway speed enforcement for a lot cheaper than the wage of police officers sitting and waiting at a trap all day, and will catch everyone instead of just a bunch of arbitrarily (or worse) chosen randos from the pack.
For outside of highways, you can still automate speed enforcement, but you also need to be designing roads that discourage speeding. Current ASHTO/MUDCD rules do the opposite, constantly pushing roads to have higher speeds in pursuit of better letter grades even though this represents a constant one-way ratchetting of road danger.
The purpose of road rules, including speed limits, needs to be SAFETY, not funding. Pretty much every municipality outside of the US that pursues vision zero programs does so primarily with engineering rather than enforcement, and when enforcement is used, camera-based enforcement is more effective and less likely to murder some random person of color.