Axlebox bearings are safety-critical components carrying high-frequency alternating loads and wheel-rail impact over long maintenance intervals. Requirements cover high reliability margins, impact resistance, robust sealing against rain, snow and washing media, stable performance from −40℃ to 120℃, and low unsprung mass. Trends point to longer maintenance-free life through profiled rollers, high-performance seals and long-life grease, plus sensor-integrated smart axlebox bearings enabling condition-based maintenance.