The pendulum tester is a portable ASTM method , has been used successfully since at least 1971 for assessing pedestrian traction potential .
Is a national standard for pedestrian traction in 48 nations on four continents .
The pendulum tester is a portable ASTM method , has been used successfully since at least 1971 for assessing pedestrian traction potential , and is a national standard for pedestrian traction in 48 nations on four continents .