• International Journal of Highway Engineering
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• v.15 no.3
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• pp.31-36
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• 2013

PURPOSES: This study is to investigate a generated traffic noise when vehicle pass over a transverse rumble strip at toll plaza of highway. METHODS: To investigate traffic noise at toll plaza of highway, Pass-by method which is the most common used for measuring traffic noise was adopted and the traffic noise at toll plaza was measured for 10 min per hour for 11hours(13:00~24:00). RESULTS: The measured traffic noise by pass-by method was changed as function of the transverse rumble strip configuration. Generally, the maximum difference among three noise measurement sections was 7 dB(A). It might be related with traffic speed. Also, the measured traffic noise was strongly generated from a passenger car which was 2 axle. It means that the most of traffic noise on the road is generated at tire/pavement interface of the passenger car. CONCLUSIONS: The traffic noise was strongly related with vehicle speed and transverse rumble strip configuration on the road. For driver safety, the transverse rumble strip is definitely necessary. However, the complaints from residents near highway was increased by traffic noise from transverse rumble strip. Therefore, To satisfy both safety and reduction of traffic noise, the development of configuration of transverse rumble strip is necessary in the further study.

• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.7-14
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• 2006

Most researches about rumble strips have Presented only the before-and-after analysis of the accidents. So, Researchers have not dealt with the estimation of rumble strip's effectiveness on the driver's alertness. In this study. the effectiveness of the rumble strips on the driver's alertness was estimated by measuring the bio-signal transmitted from the driver. The bio-signal acquired for this experiments were theta wave in central lobe. The experimental results revealed that the theta waves as measured form the drivers's head while in the rumble strip section differed from those while in non-rumbled section; 74 percent decrease in theta wave value, respectively. This fact finding could mean that the driver's alertness increased from 74 percent while in the rumble strip section of the road. In all five trials of driving experiments on the rumble strip section, all the drivers showed the best alertness as measured by the theta waves in the first driving trial.

• International Journal of Highway Engineering
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• v.15 no.6
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• pp.93-101
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• 2013

PURPOSES : The rumble strip installed at the highway near the tollgate has the purpose to reduce the vehicle velocity or prevent sleepiness by awakening people to the danger. These rumble strip has different vibration decibel from the rumble strip shapes, resulting in some fatigue damage to human because a driver suffers from a lot of stress and displeasure. In this connection, the objective of this paper is to analyze the vibration decibel perceived by a driver in the vehicle under some conditions. METHODS : The vibration decibel conveyed from the tire can be analyzed. The frequency analysis methods were used according to DFT (Discrete Fourier Transform) analysis, FFT (Fast Fourier Transform) analysis, CPB (Constant Percentage Bandwidth) analysis. But the frequency analysis method in this paper is the 1/24 OCT(Octave) band analysis because of the convenience of the analysis and the overall vibration amplitude along the frequency. RESULTS : By using the results of the vibration decibel after analyzing the 1/24 OCT band analysis, these results can be compared from some conditions (e.g., rumble strip shape, uniform velocity of a vehicle, road condition, mass of a vehicle). As a result, the numerical values of decibel are not directly proportional to the vehicle velocity. CONCLUSIONS : At the condition that a vehicle is passing by the rumble strip, the value of a vibration decibel at the rumble strip of the cylinder shape is smaller than the rumble strip of rectangular shape regardless of the rumble strip depth and width. At the mass condition, the more a vehicle is massive, the more the vibration decibel increases. At the road condition, the vibration decibel at the wet road is smaller than the value at dry road condition.

• Journal of the Korean Society of Safety
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• v.31 no.1
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• pp.95-104
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• 2016

In general, the crash reduction effect of the rumble strip is reported to be about 30% in Korea, while it is about 40-60% in the United States. However, the effect is erroneously overestimated because the simple comparison was only made before and after the installation. Accordingly, this study will reassess the crash reduction effect of the rumble strip. The study will also examine the former's geometric characteristics as well as its effect on the causes of the crash. This study analyzed the crash effect while taking into consideration the changes in the horizontal and vertical alignment, including the width of pavement shoulders, using the crash data for two years before and after the installation of the rumble strip. The types of crash caused by the rumble strip were identified using the classification discriminant function. The crash effect on the rumble strip is estimated to be 28.3%, but the pure effect, with the exception of the effect by other elements, was analyzed to be 7.4%. For each expressway design element, the downhill section (2.0-3.0%), the section with less than 3,000 m and more than 10,000 m of the curve radius, and the section with less than 3.0 m of the pavement shoulder width were found to be effective in crash reduction. For each cause of crash, the rumble strip was analyzed to be effective in the reduction of crash caused by "not keeping the safe distance", "sleeping", "negligence in keeping eyes forward", and "excessive handle operation". In particular, the rumble strip was analyzed and seen to be especially effective in preventing crash caused by "not keeping a safe distance," and "sleeping". The installation of the rumble strip was found to be effective in the prevention of crash caused by "not keeping the safe distance" and "sleeping". The results of this study may thus be used in deciding the causes of crash and the installation location of the tailored rumble strip that would be suitable for the geometric characteristics of the roads. This study will also be helpful in the establishment of future traffic safety measures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.289-294
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• 2010

It is well known that rumble strips contribute to reduce traffic accidents. The present paper provides the reduction effect of traffic accidents under specific highway geometrics after rumble strip installation. Traffic accidents on freeway sections before and after rumble strip installation are compared when conditions of the highway geometric characteristics such as horizontal, vertical geometrics are given. It is shown that rumble strips are effective under highway geometric conditions of down slopes or right curvatures. It is also shown that rumble strips are still effective with shorter length of installation.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.65-74
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• 2007

There have been research and studies on rumble strip effectiveness in terms of accident reduction since rumble strips were first installed in 1950's. Research has shown that rumble strips reduce accidents from drowsy and inattentive driving. The present research statistically analyze the accident reduction effect of rumble strips based on accident reports obtained from rumble strip installed 377 places of nation wide freeway lines. Based on the results, rumble strips are effective in reducing accident frequencies 32.3%. The probable various factors inducing accidents are identified. These include drowsiness, speeding, inattentiveness, vehicle defectiveness, and short headways. It was found that rumble strips are effective in reducing A, B, C leveled accidents, and in reducing clear, cloudy, and rainy weather accidents. The results may make clear and expand probable types of accidents that rumble strips would reduce, then reduce the total accidents on freeway lines.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.177-186
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• 2009

Rumble strip was introduced in highway pavement for driver's safety in Korea on 2000. With proving its effectiveness, total length of highway with rumble strip has increased. This research team suggested a modified form of the existing rumble strip, which was placed on new concrete pavement during construction. The modified construction equipment was applied on test section at PyungTeak-Eumsung highway with some performance experiments. Through the equation of stopping sight distance proposed AASHTO, the modified form is safer than the existing one due to 0.65m of extra width. The indoor noise test showed that the modified form $3.5{\sim}9dB(A)$ noisier than the main pavement, which wasn't applied by rumble method. Therefore, it was one of alternatives to prevent sleeping. The modified form made the frequency effected on man's eye. There were no differences of the noise and vibration between modified form and existing one. However, that driver who participated on operating test on that section felt that the former was safer than the latter. It can be concluded that modified form can be applied to the new concrete pavement, that will decrease traffic accident.

• International Journal of Highway Engineering
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• v.14 no.5
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• pp.201-206
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• 2012

PURPOSES: This study evaluated a measuring technique for tire-pavement interaction noise that uses a noble close proximity (NCPX) method as well as for noise level measured inside of a car (e.g., Inside Noise Level) in term of rumble strips constructed at a tall gate. METHODS: According to the measurements of NCPX and inside noise level (INL), 1/3 octave band frequency analysis and overall noise level calculation were conducted in order to evaluate noise levels of NCPX and INL, depending on types of rumble strips. RESULTS: The tested sections of general concrete pavement surface and two different types of rumble strips were evaluated, using 1/3 octave band frequency analysis and overall noise level. From the analyzed results, it can be concluded that rumble strips generate a relatively huge noise levels when compared to the concrete pavement surface. CONCLUSIONS: Noting that above 3 dBA different noise levels can let drivers know that they are getting close to toll gate; therefore, they should apply their brakes. Thus, the noise levels of rumble strips are required to be reduced, based on considering the neighbors living near toll gates.

• International Journal of Highway Engineering
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• v.15 no.6
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• pp.33-39
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• 2013

PURPOSES : This research investigates traffic noise characteristics as change the transverse rumble strips shape from rectangular to cylinder at toll plaza of highway. METHODS : The traffic noise was investigated at two different places at toll plaza of highway. One is modified grooving, another is employed cylinder shape of TRS instead of rectangular shape of TRS. A measurement of traffic noise was conducted at same location and time period. The traffic volume information was gotten from office of highway office and vehicle speed was measured by speed measuring device. The traffic noise measurement was conducted from 13:00 to 23:00 and by pass-by method. Also, the traffic noise was measured behind noise barrier. Various distance from noise barrier(7.5m, 30m, 50m) and different heights(1.2m, 3m, and 5m) were parameter for measurement of traffic noise in this study. RESULTS : The class 1 vehicle was contributed from traffic volume which was increased 1,500. However, the distribution of traffic speed didn't change compare to previous investigated period. From this study, It was found that the external traffic noise was changed as function of geometric shape of TRS. The external noise from modified grooving was less than 1.2dB(A) of the current TRS. A difference of traffic noise was 20dB(A) before and after barrier. It came from a noise barrier effect as reduction of traffic noise. According to investigate a traffic noise distribution near barrier, there is similar noise characteristic as function of height at 7.5m distance from noise barrier. Also, There is no different traffic noise between 30m and 50m from source of the noise of sound barrier. CONCLUSIONS : Based on this traffic noise investigation result, there is a clear characteristic difference as changed TRS shape. The traffic noise was reduced by changed TRS shape. Specially, traffic noise was decreased although the traffic volume was increase for same investigation time and period. It is implied that cylinder type of TRS significantly reduces the traffic noise. The specification of various TRS will be studied in the future.

• Proceedings of the KOR-KST Conference
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• 2007.11a
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• pp.412-417
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• 2007