Table 4: Median frequencies (Hz).

Speed Sectors Agro Material Aluminium Carbon
m std m std m std
15km/h Road 63.0 6.4 67.6 3.9 65.8 3.2
Cobblestone 31.2 4.0 32.5 2.24 33.1 3.4
Speed bump 24.9 4.1 27.8 4.9 29.8 6.44
25km/h Route 40.8 2.7 41.3 3.5 42.1 4.8
Cobblestone 37.5 0.7 36.4 0.8 34.3 1.7
Speed bump 29.0 4.2 27.9 3.5 27.7 3.1
35km/h Road 37.6 3.5 38.6 3.6 38.7 4.5
Cobblestone 40.8 1.5 40.0 2.9 37.8 2.6
Speed bump 29.5 3.4 27.8 3.1 28.1 3.5