Short answer: not really—at least not in the way most people mean. Standard urban trash bins are built for waste collection, not for emergency barricades. A few heavy public bins, especially the big steel or concrete-style models, might act as a temporary obstacle if they are already stable, full, and placed in a low-risk situation. But that is very different from a proper barricade.
For public safety, the key point is that trash bins are usually movable, unevenly weighted, and not anchored. An empty plastic bin can be pushed over easily; a wheeled bin can roll; and a bin that looks heavy may still tip, slide, or create a new hazard. They also offer no reliable protection and can block escape routes or emergency access if moved into the wrong place.
So are they useful as improvised barriers? In a true last-resort moment, yes—a row of filled bins could help slow movement or create a visual warning. But it should be treated as a temporary obstacle, not as city security equipment or certified protection. If police, fire, or event staff are directing people, follow their instructions instead of improvising your own barricade. Never drag bins into traffic, and never rely on them for cover.
In short: urban trash bins are not designed as emergency barricades. They can sometimes serve as a quick, temporary obstacle, but they should never replace proper safety planning or official emergency measures.