Low noise rumble strips on roads – a pilot study
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Low noise rumble strips on roads – a pilot study Jørgen Kragh Danish Road Institute (DRI)
Transcript of Low noise rumble strips on roads – a pilot study
Low noise rumble strips on roads – a pilot study
Jørgen KraghDanish Road Institute (DRI)
Background and aim
• Rumble strips in the middle of roads to improve traffic safety
• Prevent drivers from crossing road centre line without noticing
• Noise/vibration in vehicle warn drivers• Noise level outside increases• Annoyance neighbors complain • DRI pilot study of rumble strips low
noise levels in the environment
Conclusions
• “Sinus”: < 1 dB increase• “Cylinder 0.6 m”: 2 - 3 dB increase• “Rectangle 0.3 m”: 4 – 8 dB increase
relatively to pass-by noise on old SMAvalid > 25 m from road
• Complaints: 8 dB increase
Strips Complaint
Rectangle:
• ”λ” = 0.33 m• k = 0.1 m
k"λ"
"λ"
v
kh
”Swedish”: Cylinder
• h = 0.01 m • k = 0.15 m• ”λ” = 0.33 m
DRI pilot• h = 0.01 m • k = 0.15 m• ”λ” = 0.6 m
Sinus: λ = 0.6 m
-8
-6
-4
-2
00,0 0,5 1,0 1,5[m]
[mm]7 mm / 0.60 m
-8
-6
-4
-2
00,0 0,5 1,0 1,5
4 mm / 0.60 m[mm]
[m]
Overview of strips
Rumble strip No. [-]
Indentation
1 Segment of cylinder, max. 10 mm deep 2 Sinus 7 mm top to bottom 3 Sinus 4 mm top to bottom 4 Rectangle 4 mm deep 5 Rectangle 8 mm deep
”Swedish”
Sinus 7 mm
Measured profiles
• Swedish
• Sinus 7 mm
• Sinus 4 mm
20
25
30
35
109 109,5 110 110,5 111 111,5 112 112,5 113 113,5 114
[m]
[mm]
20
25
30
35
80 80,5 81 81,5 82 82,5 83 83,5 84 84,5 85
[m]
[mm]
20
25
30
35
10 10,5 11 11,5 12 12,5 13 13,5 14 14,5 15
[m]
[mm]
Cars and tyres
Car No. 1 2 3 Make Volkswagen Skoda Toyota Model Golf 1,8 Octavia 1,9 TDI Combivan (Corolla Verso) Year 1995 2006 2003 km 200.000 5.000 15.000 Tyres
FrontGislaved Speed 516
185/60 R14 82T Tyres
RearMichelin Energy 185/60 R14 XT2
Continental ContiEcontact 3195/65 R15 91H
Goodyear Ultragrip 6 (M+S) 195/65 R15
Increments in noise level
Rumble strip No. [-]
Indentation Far lane [dB]
Near lane [dB]
1 Segment of cylinder, 10 mm deep 3 2 2 Sinus 7 mm top to bottom 1 0.5 3 Sinus 4 mm top to bottom 1 0.5 4 Rectangle 4 mm deep 6 4 5 Rectangle 8 mm deep 8 5
rel. Old SMA 11
Near lane
76
78
80
82
84
86
1.1 1.2 1.3 2.1 2.2 2.3 3.1 3.2 3.3 4.1 4.2 4.3 5.1 5.2 5.3 R.1 R.2 R.3
[dB]
Near lane
Far lane
76
78
80
82
84
86
1.1 1.2 1.3 2.1 2.2 2.3 3.1 3.2 3.3 4.1 4.2 4.3 5.1 5.2 5.3 R.1 R.2 R.3
[dB]
Far lane
CL
0,0
0,4
0,8
1,2
1,6
2,0
2,4
0 5 10
Near lane Far laneMicrophone
+z-y dB +z dB -y dB0 dB
x x Distance [m]
Height [m]
Model Optimize Measured - Calculateda) Near – Far levelb) Strip rel. Ref
-2
-1
0
1
2
3
4
5
6
-5 0 5 10 15 20 25 30
Increment z [dB]
Nea
r - F
ar
[dB
]Near – Far = F(z)
Final result
Rumble strip No. [-]
Far lane [dB]
Near lane [dB]
1 3,0 1,8 2 0,8 0,4 3 0,9 0,5 4 5,6 3,7 5 7,5 5,2
Conclusions
• “Sinus”: < 1 dB increase• “Cylinder 0.6 m”: 2 - 3 dB increase• “Rectangle 0.3 m”: 4 – 8 dB increase
relatively to pass-by noise on old SMAvalid > 25 m from road
• Complaints: 8 dB increase
