Runway safety area
A runway safety area (RSA) or runway end safety area (RESA, if at the end of the runway) is defined as "the surface surrounding the runway prepared or suitable for reducing the risk of damage to airplanes in the event of an undershoot, overshoot, or excursion from the runway." Past standards called for the RSA to extend only 60m (200 feet) from the ends of the runway. Currently, the international standard ICAO requires a 90m (300 feet) RESA starting from the end of the runway strip (which itself is 60m from the end of the runway), and recommends but not requires a 240m RESA beyond that.