A height limit is a maximum allowed height for vehicles (including any cargo or attachments) on a specific road, bridge, tunnel, or underpass. It's used to prevent tall vehicles from hitting overhead structures, which can be dangerous and cause serious damage.
Warning for electricity cables, safe height of 4,50 meter or 14 feet 7 inches. Warning for a traffic bump. (Kildare, Ireland) © Wikimedia.org/Leimanbhradain, CC BY-SA