Research on motor transport produced noise on gravel and asphalt roads/Autotransporto keliamo triuksmo zvyrkeliuose ir asfaltuotuose keliuose tyrimas/Transporta plusmas radita troksna izpete uz grants un asfalta celiem/ Liiklusvahendite tekitatud mura uuring kruus- ja asfaltkatetel.

Leipus, Linas ; Butkus, Donatas ; Janusevicius, Tomas 等

1. Introduction

As industry develops, cities grow and the number of vehicles increases, zones of acoustic discomfort also expand increasingly. Skrodenis et al. (2009) note in their paper that people are constantly affected by noise produced by machines, equipment and devices. Motor transport is the main source of noise in cities and villages. The noise carried from streets, roads and highways forms a part of 80% of athmospheric pollution (Grubliauskas, Butkus 2009). The acoustic pollution produced by all types of vehicles occurs as noise and vibration (Topila et al. 2000).

Nowadays, noise has become a common problem, covering all areas of people's life and work. The harm of noise must be evaluated in pathophysiological, economical and sociological aspects and in accordance with the latest scientific achievements (Bazaras et al. 2008; Paslawski 2009; Willich et al. 2006).

Various studies confirmed the influence of noise on cardiac infarct risk at places such as work and residence (Zavadskas et al. 2007a; b).

Research works carried out in Europe showed that almost 25% of population is annoyed by noise produced by vehicles. The noisiest vehicles are trucks, buses, sports cars and motorbikes (Oskinis et al. 2004). During the research performed in the USA, it was determined that the noise level produced by heavy vehicles moving at a speed of 100 km per hour had reached a value of 87 dBA, medium vehicles--83 dBA and light vehicles--77 dBA.

On 25 June 2002, the European Parliament and the Council adopted Directive 2002/49/EC On Assessment and Management of Environmental Noise. This is the first document in Europe which seeks to legally regulate environmental noise (Nemaniute 2007).

Vehicle produced noise on roads is mostly influenced by the following factors: vehicle traffic intensity and driving speed, its change and reduction of friction between wheels and road (Baltrenas et al. 2007; Butkus et al. 2008; Vaiskunaite et al. 2009).

The main cause of the increased noise in streets is a high number of old and technically badly-maintained cars. During the last ten years the transport flow in Lithuania has increased 2.4 times. Because of this, a number of traffic accidents have also increased. The drivers experience longer queues and time losses at junctions (Antov et al. 2009). As a result, environment pollution with exhaust fumes, and traffic noise has increased considerably (Jonasson 2007; Kapski et al. 2008).

A major part of Lithuania's network of regional and local roads is comprised of roads with gravel and roads with worn-out AP. Technical condition of roads is the worst where the intensity of traffic is growing constantly and the road pavement is not protecting the road structure from the traffic loads and impact of weather conditions. Cars driving on roads of bad condition raise dust and produce noise and this negatively impacts the business and residential zones in regions (Grazuleviciene et al. 2004). Rutted asphalt roads not only worsen driving quality and increase dustiness but also create additional noise. To reduce rut formation Radziszewski (2007) in his paper recommends using asphalt mixture and binder modification effective for improving asphalt properties. Laurinavicius and Oginskas (2006) in their work indicate causes of rut formation and presents recommendations on fighting it.

Noise has a negative impact on our body although we do not feel it. The reaction of each individual to noise is different, however the body is under constant stress (Levine et al. 1998; Malinauskiene et al. 2004; Passchier, V. W., Passchier, W. F. 2000).

With the purpose of reducing this impact the Gravel Road Paving Programme has been implemented in Lithuania since 2004. First of all the roads passing through villages are paved, then the roads with higher traffic intensity and gravel roads connecting larger villages with the network of asphalt roads. Building of bypasses and paving of gravel roads are highly significant measures for air quality improvement. To reduce motor transport risks to human health it is planned not to exceed the noise level of 65 decibels on the newly built and reconstructed roads in living environments, to reduce the number of traffic accidents and to inform the public of potential health impact (Miskinis 2006).

An alternative to road noise reduction without road paving is the erection of noise absorbing or reflecting walls along the roads (Grubliauskas, Butkus 2009; Ishizuka, Fujiwara 2004; Vaisis, Janusevicius 2008).

The objective of the research is to make an analysis and to compare the levels of motor transport produced noise on the roads of regional significance with asphalt and gravel pavement in Moletai district. The measurements were taken in wintertime and summertime, when there is difference in traffic intensity and also in driving and climate conditions.

2. Noise measurement technique

The nature of noise is determined prior to the measurement. Motor transport noise is variable dependent on time of the day. Noise produced by motor transport flow is constituted of the noise produced by single cars. Variable noise is noise with variation higher than 5 dBA and constantly changing, intermitting or pulsating and it is assessed by the reciprocal and max sound levels as it is indicated in the document LST ISO 1996-1:2005 Akustika. Aplinkos triuksmo aprasymas, matavimas ir ivertinimas. 1 dalis. Pagrindiniai dydziai ir ivertinimo tvarka (Acoustics. Description, Measurement and Assessment of Environmental Noise. Part 1: Basic Quantities and Assessment Procedures (idt ISO 1996-1:2003)).

The Bruel and Kjaer 2260 noise and vibration meter was used to measure the reciprocal and max sound levels. The relative error of this meter is [+ or -] 1.5%. The Bruel and Kjaer 2260 meter is a state-of-the-art first class sound level meter and sound analyser. This mobile device is suitable for the required measurements and full analysis of measured data when performing the research of noise in living environments and workplaces.

During the measurement the microphone of the noise meter is held at a height of 1.2-1.5 m and not less than 0.5 m away from the person who is performing the measurement and is also pointed to the noise source.

Measuring conditions shall conform to certain requirements: measurement shall not be performed when it is snowing or raining or wind speed is exceeding 5 m/s. In the event that the wind speed is 5 m/s or more, the microphone shall be covered with a special screen. Also other meteorological conditions shall be recorded: wind direction, air temperature, pressure and humidity. All measuring conditions met the current equirements.

The measurement of vehicle produced noise at the chosen location was performed (by LST ISO 1996--2 standart) with two microphones at the same time:

--at point A (at a distance of 7.5 m from the axial line of the trajectory of a moving car) and point B (at a distance of 20 m);

--at point A (at a distance of 7.5 m from the axial line of the trajectory of a moving car) and point C (at a distance of 50 m) (Fig. 1).

The measurements of car produced noise levels were performed on roads of regional significance of Moletai district. The Moletai district was chosen due to the fact that it has both asphalt and gravel road pavement.

[FIGURE 1 OMITTED]

Typical points in consideration of pavement nature and different environmental conditions were selected (Fig. 2).

The first measurement point was an asphalt road with an arable field on one side and a meadow with thinly growing bushes on the other; an open location was selected for the measurement.

The second measurement point was a gravel road with an arable field on one side and a meadow with thinly growing bushes on the other; an open location was selected for the measurement.

The third measurement point was a gravel road with coniferous wood with thinly growing bushes starting at 10 m from the road on both sides.

The fourth measurement point was an asphalt road with coniferous wood with thinly growing bushes starting at 10 m from the road on both sides.

The fifth measurement point was selected on an asphalt road going uphill with thinly growing bushes and single trees at 15 m from the road on both sides.

The sixth measurement point was selected on a gravel road going uphill with thinly growing bushes and single trees on both sides at 15 m from the road.

Noise level dependence on light vehicle speed was measured during summertime. The station was located leeward from the road. The wind speed was 1.2 m/s, air temperature 22[degrees]C, relative humidity of 54%. In winter-time measurements were taken also leeward. The wind speed was 1.8 m/s, air temperature 6.3[degrees]C, relative humidity of 44%.

[FIGURE 2 OMITTED]

3. Results of transport noise measurement

Fig. 3 shows the reciprocal and max noise levels of a car driving in an open area in wintertime and summertime. Noise levels were measured while a car was driving at a speed of 50 km/h on roads with gravel and AP. As we can see from the figures, upon moving away from the driving car by 7.5 m to 50 m, the reciprocal noise levels on roads with different pavement decreased equally. The difference was 12 dBA in wintertime and 17 dBA in summertime.

As seasons change so do the sound reflections, especially when driving in wooded areas and changes also occur in coarseness of the road pavement. These changes have influence on the fact that reciprocal noise level at a distance of 7.5 m in summertime is higher by 3 dBA than in wintertime. Upon moving away the noise level is higher in wintertime. The max noise level on roads with AP upon moving away from the driving car by 7.5 m to 50 m decreases by 17 dBA in wintertime and 19 dBA in summertime. The max noise level on the road with gravel pavement decreases by 16 dBA in wintertime and 17 dBA in summertime.

On comparing the levels of reciprocal noise on roads with different pavements we see that noise level on roads with gravel pavement, when driving in an open area, is higher by 3 dBA in wintertime and summertime than it is on roads with AP. Noise caused by the tires and car vibrations is a consequence of pavement roughness.

Fig. 4 shows the reciprocal and max levels of noise of a car driving in wooded area in wintertime and summertime.

This time the reciprocal noise level on roads with AP upon moving away from the driving car by 7.5 m to 50 m decreased by 15 dBA in wintertime and 20 dBA in summertime. The noise level on the road with gravel pavement decreased by 16 dBA in wintertime and 24 dBA in summertime. This is influenced by winter and summer herbaceous vegetation which absorb and reflect noise in different ways.

The difference was probably influenced by the noise absorption in the wooded area in summertime. The max noise level on roads with AP in the wooded area decreased equally by 22 dBA in summertime and wintertime. The max noise level on roads with gravel pavement decreased by 20 dBA in wintertime and 27 dBA in summertime.

The reciprocal and max noise levels at measurement points of 7.5 m and 20 m in the wooded area were higher in summertime than in wintertime. At the measuring point of 50 m, the noise level was higher in wintertime. The results obtained lead us to an assumption that reflection from foliage of undergrowth and glade form a particular screen which prevents noise from being carried away.

Fig. 5 compares the changes in noise spread in open and wooded areas upon moving away from the noise source by 50 m.

As we can see in Fig. 5 the reciprocal noise level in summertime is lower by 2 dBA than in wintertime. Upon moving away from the noise source by 50 m, motor transport produced reciprocal noise in wooded areas is lower by 6 dBA than in open fields (Fig. 5). The noise spread reduces equally both on roads with AP and gravel roads. All this shows that growing trees have fair influence on noise suppression.

The max noise level in summertime is lower by 1 to 3 dBA than in wintertime (Fig. 5).

Fig. 6 compares noise levels produced by a car driving uphill on roads with asphalt and gravel pavement.

The results obtained show that the reciprocal noise level when driving uphill on the road with gravel pavement at a point of 7.5 m is higher by 4 dBA than on road with AP. This noise at a point of 50 m on road with AP is lower by 3 dBA than on gravel road (Fig. 6).

A light vehicle driving on the road with gravel pavement at a speed of 50 km/h up a hill with a steepness of 5% at a point of 7.5 m produces a noise more intense by 2 dBA than driving on open area at the same speed.

Fig. 7 shows the dependence of reciprocal and max noise levels on car speed when driving in an open area on roads with asphalt and gravel pavement in wintertime. As light vehicle speed increases from 40 km/h to 50 km/h, the level of reciprocal noise at a distance of 7.5 m from a car rises by 2 dBA. Upon moving away by 7.5 m to 50 m, the spread of the noise produced by a driving car reduces by 12 dBA.

Comparing the noise levels on roads with different pavements we see that reciprocal noise level on roads with gravel pavement is higher by 3 to 4 dBA. This difference in noise levels occurs at all distances (from 7.5 to 50 m) from a driving car.

Fig. 8 shows the dependence of reciprocal and max noise levels on car speed when driving in wooded areas on roads with asphalt and gravel pavement in wintertime. As light vehicle speed increases from 40 km/h to 50 km/h, the level of noise rises by 2 dBA. Upon moving away by 7.5 m to 50 m, the spread of a driving car produced noise on roads with AP decreases by 15 dBA and by 16 dBA on roads with gravel pavement.

A car produced noise on roads with gravel pavement in wooded areas in wintertime is higher by 3 dBA than on roads with AP.

Fig. 9 shows the dependence of reciprocal and max noise levels on car speed when driving in an open area on roads with asphalt and gravel pavement in summertime.

The reciprocal noise level of a car driving at a speed of 50 km/h at a distance of 7.5 m on road with gravel pavement is higher by 3 dBA than on road with AP. When driving at a speed of 70 km/h, the difference is 2 dBA.

The difference of reciprocal noise level of a car driving in an open area at various speeds (from 7.5 to 50 m) can be seen in Fig. 10.

The results obtained show that upon increasing car speed from 50 km/h to 70 km/h, the reciprocal noise level, considering metering points, increases by 5 dBA to 7 dBA on asphalt roads and 4 dBA to 8 dBA on gravel roads.

Fig. 11 shows the dependence of reciprocal and max noise levels on car speed when driving in wooded area on roads with asphalt and gravel pavement in summertime.

As we can see, upon increasing speed from 50 km/h to 70 km/h when driving in woods, the noise level on sectors with AP increases by 3 dBA to 4 dBA and 5 dBA to 6 dBA on roads with gravel pavement.

4. Conclusions

Motor transport produced noise depends on the distance from the noise source, car driving speed, territory conformation and obstacles in the way of noise spread (herbs and woody vegetation).

The noise level on roads with gravel pavement when driving in an open area in wintertime and summertime is higher by 3 dBA than on roads with AP.

The noise level in wooded areas on roads with gravel pavement is higher by 4 dBA in summertime and by 6 dBA in wintertime than on roads with AP.

As light vehicle speed increases from 40 km/h to 50 km/h in wintertime the noise level has a tendency to rise by 2 dBA.

As car speed increases from 50 km/h to 70 km/h in summertime the noise level rises by 5 dBA.

Upon moving away from the noise source by 50 m a car produced noise in the open and wooded areas is lower by 2 dBA in summertime than it is in wintertime.

doi: 10.3846/bjrbe.2010.18

Received 09 December 2009; accepted 01 July 2010

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[TEXT NOT REPRODUCIBLE IN ASCII], B. 2004. [TEXT NOT REPRODUCIBLE IN ASCII] [Obelianis, Malinauskiene. Investigation of Occupational Factors and Health of Urban Transport Workers], [TEXT NOT REPRODUCIBLE IN ASCII] [Medical and Social Expertise and Rehabilitation: Collection of Scientific Articles] 6: 327-330.

Linas Leipus (1), Donatas Butkus (2), Tomas Janusevicius (3)

Dept of Enviroment Protection, Vilnius Gediminas Technical University, Sauletekio al. 11, 10223 Vilnius, Lithuania

E-mails: (1) Linas.Leipus@vgtu.lt; (2) butkus@vgtu.lt; (3) jtomas@vgtu.lt

Fig. 3. The reciprocal and the max noise levels of a car driving
in an open area

Noise level, dBA

v = 50 km/h

Asphalt pavement

                                    7.5 m   20 m   50 m

Wintertime reciprocal noise level   61      56     49
Wintertime max noise level          70      60     53
Summertime reciprocal noise level   64      51     47
Summertime max noise level          69      54     50

Gravel pavement

                                    7.5 m   20 m   50 m

Wintertime reciprocal noise level   64      60     52
Wintertime max noise level          72      65     56
Summertime reciprocal noise level   67      57     50
Summertime max noise level          72      61     55

Note: Table made from bar graph.

Fig. 4. The reciprocal and the max noise levels of a car driving
in the wooded area

Noise level, dBA

v = 50 km/h

Asphalt pavement

                                    7.5 m   20 m   50 m

Wintertime reciprocal noise level   58      49     43
Wintertime max noise level          67      53     46
Summertime reciprocal noise level   61      51     41
Summertime max noise level          66      56     44

Gravel pavement

                                    7.5 m   20 m   50 m

Wintertime reciprocal noise level   62      52     46
Wintertime max noise level          69      56     49
Summertime reciprocal noise level   67      53     43
Summertime max noise level          73      57     46

Note: Table made from bar graph.

Fig. 5. The reciprocal and the max noise levels spread
dependence on landscape conditions

Noise level, dBA

v = 50 km/h

Asphalt pavement

                                    50 m Field   50 m Forest

Wintertime reciprocal noise level   49           45
Wintertime max noise level          53           46
Summertime reciprocal noise level   47           41
Summertime max noise level          50           44

Gravel pavement

                                    50 m Field   50 m Forest

Wintertime reciprocal noise level   52           46
Wintertime max noise level          56           49
Summertime reciprocal noise level   50           43
Summertime max noise level          55           46

Note: Table made from bar graph.

Fig. 6. The reciprocal and the max noise levels of a car driving
uphill

Noise level, dBA

v = 50 km/h

Asphalt pavement

                                    7.5 m   20 m   50 m

Wintertime reciprocal noise level   62      52     49
Wintertime max noise level          69      60     46
Summertime reciprocal noise level   64      54     49
Summertime max noise level          69      61     55

Gravel pavement

                                    7.5 m   20 m   50 m

Wintertime reciprocal noise level   66      58     52
Wintertime max noise level          73      66     58
Summertime reciprocal noise level   68      59     52
Summertime max noise level          75      65     58

Note: Table made from bar graph.

Fig. 7. Dependence of reciprocal and max noise levels on car
speed when driving on road with gravel pavement and AP in
wintertime

Noise level, dBA

v = 40 km/h

                                          7.5 m   20 m   50 m

Asphalt pavement reciprocal noise level   59      53     47
Asphalt pavement max noise level          67      58     51
Gravel pavement reciprocal noise level    63      56     50
Gravel pavement max noise level           71      64     63

v = 50 km/h

                                          7.5 m   20 m   50 m

Asphalt pavement reciprocal noise level   61      56     49
Asphalt pavement max noise level          70      60     53
Gravel pavement reciprocal noise level    64      60     52
Gravel pavement max noise level           72      65     56

Note: Table made from bar graph.

Fig. 8. Dependence of reciprocal and max noise levels on car
speed when driving in wooded area on road with asphalt and
gravel pavement in wintertime

Noise level, dBA

v = 40 km/h

                                          7.5 m   20 m   50 m

Asphalt pavement reciprocal noise level   57      46     42
Asphalt pavement max noise level          65      50     45
Gravel pavement reciprocal noise level    60      49     44
Gravel pavement max noise level           67      53     47

v = 50 km/h

                                          7.5 m   20 m   50 m

Asphalt pavement reciprocal noise level   58      49     43
Asphalt pavement max noise level          67      53     46
Gravel pavement reciprocal noise level    62      52     46
Gravel pavement max noise level           69      56     49

Note: Table made from bar graph.

Fig. 9. Dependence of reciprocal and max noise levels on car
speed when driving in an open area on road with asphalt and
gravel pavement in summertime

Noise level, dBA

v = 50 km/h

                                          7.5 m   20 m   50 m

Asphalt pavement reciprocal noise level   64      51     47
Asphalt pavement max noise level          69      54     50
Gravel pavement reciprocal noise level    67      57     50
Gravel pavement max noise level           72      61     55

v = 70 km/h

                                          7.5 m   20 m   50 m

Asphalt pavement reciprocal noise level   69      58     54
Asphalt pavement max noise level          75      61     57
Gravel pavement reciprocal noise level    71      65     65
Gravel pavement max noise level           77      69     58

Note: Table made from bar graph.

Fig. 10. Dependence of reciprocal noise levels on car speed
when driving in an open area on roads with different pavements
in summertime

Reciprocal level, dBA

Asphalt pavement

          7.5m   20 m   50 m

50 km/h   64     51     47
70 km/h   69     58     54

Gravel pavement

          7.5m   20 m   50 m

50 km/h   67     57     50
70 km/h   74     65     55

Note: Table made from bar graph.

Fig. 11. Dependence of reciprocal and max noise levels on car
speed when driving in wooded area on road with asphalt and
gravel pavement in summertime

Noise level, dBA

v = 50 km/h

                                          7.5 m   20 m   50 m

Asphalt pavement reciprocal noise level   61      51     41
Asphalt pavement max noise level          66      55     44
Gravel pavement reciprocal noise level    67      53     43
Gravel pavement max noise level           73      57     46

v = 70 km/h

                                          7.5 m   20 m   50 m

Asphalt pavement reciprocal noise level   64      55     50
Asphalt pavement max noise level          70      60     54
Gravel pavement reciprocal noise level    72      58     52
Gravel pavement max noise level           79      62     57

Note: Table made from bar graph.