Dahlia sounds as if she would have approved of English criminal justice in the 18th Century. All those capital crimes yet the system was so ineffective that crime was absolutely rampant. The problem for the system was that it was difficult to get caught.
What changed the game was the introduction of the New Police in 1829 in London, an idea which spread to the rest of the country in the ensuring years. Yes, there should be appropriate punishment for crime but the chances of actually being apprehended should be increased so that the deterrent value of punishment is enhanced.
What are your DUI laws like? Where I am it's illegal to drive above .05%. Every police officer here is permitted to stop any driver to test them at any time. We also have breath testing stations which test large numbers of drivers for alcohol or drugs On the sentencing end of the equation for a first offence the max is 3 mths in prison, for a subsequent offence the max is 6 mths and disqualification from driving is lengthy.
It has had an effect. But the most important change in the last twenty or so years has been the social disapproval of DUI. No longer is is acceptable when you're at the pub to boast about how off your face you were last night but you managed to get home in one piece.
In the state next to mine some years ago the traffic safety authorities ran a series of tv, radio and print ads which were aimed to stigmatising DUI drivers. The line went, "If you drink and drive, you're a bloody idiot!" At one inner city pub someone had scrawled underneath one of the ads, "But if you get home you're a bloody legend!" That caused great mirth at the time. Nowadays it would be seen as poor taste humour.
"Unbloodybreakable" DCI Gene Hunt, 2008