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 |