How Can Traffic Noise Be Reduced by Changing Driving Styles and Road Surfaces?

Traffic behavior psychology is defined as the study of behavior and psychological processes of different traffic participants. Its aim is to try to identify specific behavioral patterns of users of different traffic types with the ultimate goal of developing effective accident prevention measures. There are two main approaches that can help psychologists develop and implement measures against traffic accidents. First, traffic psychology can act as a “helper” of science with a dominant traffic engineering field. Road safety engineering solutions aim to optimize internal road safety. A safe path can be defined as one that is designed, operated or modified as follows:

• Warns the driver of unusual or strange features.

• It informs the driver about the road condition.

• Guides the driver on unusual tracks.

• Controls the passage of drivers through trouble spots and roads (“black” traffic points).

• Has the ability to tolerate a driver’s rude or inappropriate behavior.

Engineering is strong for a significant number of traffic problems. But it would be wrong to assume that this is just an engineering solution. Engineering should also consider sociopsychological solutions that include practice, training and other activities to change the behavior of road users. In a significant number of traffic situations, psychological measures can support engineering measures by informing or motivating traffic participants to change their behavior in the desired direction, enabling the expected safety performance to work even more effectively.

With regard to the specific application of this topic to the noise issue, changes in traffic participants’ behavior will mean full ‘openness’ to newly developed traffic monitoring systems, participation in them and increasing (visually) awareness of the most vulnerable groups in traffic. people with disabilities and children). It illustrates alarming data that is a direct result of current road users’ behavior.

Quiet Road Surfaces

Many studies have already found that the predominant source of noise when driving a car at higher speeds is tire noise caused by friction between the wheels and the road surface. In light vehicles, tire noise is already the main source of noise at a speed of 30 km/h, while in heavy vehicles at speeds greater than 60 km/h, tire noise becomes the main source of noise. Tire noise depends on the following road surface characteristics:

• Surface texture

• Acoustic absorption

• Aerodynamic processes

Improving road surface characteristics, effectively reducing noise generation and amplification, will result in lower noise levels. There are several types of quiet road surfaces, and their application is mainly determined by the rate of noise reduction, the allowable speed in traffic, the composition of the traffic flow and the possible adhesion of tires to the surface during parking. Three types of bases are most commonly used in urban areas:

• Thin surface layers

• Two-layer porous asphalt

• Pouring asphalt

Thin surface layers are often referred to as thin asphalt layers or thin asphalt bases for noise reduction. These layers are usually up to 3 centimeters thick. There are a significant number of different types of thin surface layers on the market, for example in the Netherlands, with more than 40 including porous and dense types. Compared to the average dense asphalt concrete, they generally reduce noise by 2-4 decibels at 50 km/h for cars. Porous asphalt types are on average about 1 decibel quieter than dense ones; but they have a shorter duration than dense asphalt. The typical duration of a thin surface layer is 7-9 years. Thin surface layers are suitable for low and medium speed roads and are becoming increasingly popular; but roundabouts, steep slopes, bends, truck exits, etc. They are not suitable for places subject to strong stress forces such as

The two-layer porous asphalt consists of an upper layer (2.5 cm thick) and a lower layer (4.5 cm thick). The total thickness of the 7-centimeter porous layer absorbs more noise, or more precisely, between 5 and 7 decibels at the start of application. Two-layer porous asphalt is relatively expensive and suitable for high-speed roads that require extreme noise reduction. Bulk asphalt has a thin (3 centimeters) surface layer with a specific molding design.

It contains more stone than the thin surface layers and does not absorb much noise because it is non-porous; but it is stronger than other asphalts. This type of bulk asphalt test, carried out in Berlin, initially resulted in a noise reduction of 1.5 decibels. In addition to installing quiet road surfaces, another method of reducing tire noise is the manufacture of quiet car tires. There are several manufacturers that have developed and successfully released such tires. In general, the concept of comfort of tires is directly related to the loudness of their sound. One of the functions of the tire is to absorb shocks and dampen vibrations, that is, the tire is an element of the vehicle that provides travel comfort. Smaller wheels produce less noise.

Basically, a smaller tire represents a smaller surface that sticks to the road and therefore produces less noise. Besides the size, the material from which the tire is made is also important. There are also softer types of rubber that make less noise. Of course, one of the most important factors is driving speed. If you plan to drive at higher speeds, it makes sense to have tires with this performance. However, such tires are thicker and larger, so they create more noise. Weather conditions also play an important role in tire selection. Tires selected for severe weather conditions will generate more noise due to certain safety considerations, such as the need for better adhesion to the road surface. Tires selected for extreme weather conditions will produce the highest noise level. Tires selected for city driving according to their design may produce less noise. All this logically implies that winter tires will make more noise than summer tires.

Tire manufacturers can produce tires that make less noise. There are currently several models, especially the quietest summer tires, that are 4-6 dB(A) below the limit, and most newer winter models are also approaching the 2 dB(A) limit. These restrictions are set by the United Nations Economic Commission for Europe (UNECE) No. 117 uniform requirements regarding the approval of tires regarding rolling noise or traction emission on rainy surfaces. The sound pressure levels produced by each tire size are shown.

It can be concluded that noise can be limited by using modern quiet road surfaces that reduce the noise level from 3 to a maximum of 7 decibels. Unfortunately, such materials are usually 2.5 times more expensive than ordinary ones. In addition, an additional 3-4 decibels of noise can be reduced by using quieter tires; however, the choice of tires depends on the driver’s preferences and habits. In most cases, noise is reduced by speed limits on local roads and highways near residential areas, and these restrictions are often even more restrictive at night.

Noise pollution is a serious problem that affects the overall quality of life. This problem is particularly evident in urban areas where a significant amount of noise pollution is generated due to traffic. This section describes and analyzes the main traffic sources. In addition to road, rail and aircraft noise sources, other typical noise sources common in urban areas are also discussed. Bearing in mind the serious consequences of prolonged exposure to noise, at least some measures need to be taken to reduce noise levels. Today there are many initiatives and plans on how to solve this problem, but more focus is on measures directly related to traffic noise levels. In this sense, such noise reduction measures are explained and discussed in detail.

It can also be concluded that there is a need for education and some form of incentive to involve people more in the “fight” against noise and its negative effects. In this way, some kind of pressure will be created to install the necessary city infrastructure (sensor networks) and eventually citizens will get a much-needed improvement in the quality of life in the environments they live in.