Skip to main content

Advertisement

Table 2 Spearman correlations between frequency components of road noise levels and traffic flow rates

From: Road traffic noise frequency and prevalent hypertension in Taichung, Taiwan: A cross-sectional study

Vehicle type Traffic flow number Median (Q1-Q3) (vehicle/hr) Correlation coefficients
Low frequency Medium frequency High frequency
31.5 Hz 63 Hz 125 Hz 250 Hz 500 Hz 1000 Hz 2000 Hz 4000 Hz 8000 Hz
MC 42 494 (280–704) 0.505a 0.594a 0.574a 0.488b 0.351c 0.279 0.312c 0.493a 0.395a
LDGV 42 600 (360–1032) 0.630a 0.592a 0.515a 0.356c 0.276 0.248 0.204 0.301 0.218
LDDT 42 138 (80–228) 0.398b 0.371c 0.491b 0.313c 0.110 0.162 0.147 0.132 0.093
HDDT 42 42 (24–80) 0.482b 0.539a 0.456b 0.350c 0.301 0.252 0.233 0.271 0.213
Total 42 1552 (764–2132) 0.601a 0.643a 0.586a 0.457b 0.331c 0.272 0.274 0.393c 0.340c
  1. HDDT = heavy-duty diesel trucks; LDDT = light-duty diesel trucks; LDGV = light-duty gasoline vehicles; MC = motorcycles; Q1 = first quartile; Q3 = third quartile. a P < 0.001. b P < 0.010. c P < 0.050.