In 1969, the Belgian Grand Prix was boycotted by the F1 drivers because of the extreme danger of Spa. There had been ten car racing fatalities in total at the track in the 1960s, including five in the two years previous. The drivers demanded changes made to Spa which were not possible on short notice, so the Belgian Grand Prix was dropped that year. Armco barriers were added to the track and sections of it were improved (especially the Stavelot and Holowell sections), just like they had been added for the 1969 Le Mans race. One last race there the following year on the improved track was still not satisfactory enough (even after a temporary chicane was added at Malmedy just for that race) for the drivers in terms of safety, and even with the chicane, the drivers averaged 150+ mph (240 km/h) during the race. For the 1971 race, the track owners and authorities had not brought the track up to date with mandatory safety measures, and the race was cancelled. Formula One would not return to Spa until 1983 on the modern track.