The television show The Wire depicts a plan called “Hamsterdam” in which police let people sell drugs in isolated places, and only those places, without fear of arrest. Based on limited but decent empirical evidence, we can make educated guesses about what would happen if that were tried in real life. Indeed, Swiss police tried something remarkably similar in the 1980s. More generally, the results of various forms of drug legalization, depenalization, and decriminalization in Europe--such as in Portugal, which has transferred the state's method of dealing with drug use (including heroin and cocaine) from the criminal justice system to a civil administrative system since 2001--shed light on the likely strengths and weaknesses of Hamsterdam-like efforts. The Wire seems to get a lot right, including some of Hamsterdam's successes and Hamsterdam's political unsustainability. Unfortunately, The Wire might actually understate how hard it would be, even if there were no political impediments, to make sweeping improvements in real-world drug policy via Hamsterdam-like efforts.
John Bronsteen, Would Hamsterdam Work - Drug Depenalization in The Wire and in Real Life, 2018 U. CHI. LEGAL F. 43 (2018).