The sound gangs are of the strip that are installed along the roads to warn motorists when they are about to leave the lane or when needed to slow down how prevention measurement to avoid road accidents especially in conditions of poor visibility. They can be obtained from the road surface or added later. The operation, however, is the same: when the vehicle passes over it produces a noise and of vibrations which immediately draws the driver’s attention.
How they work and what sound bands are for
The sound gangs are made or installed transversely compared to the direction of the vehicle. When they are crossed with tires they produce a noise and cause a vibration of the vehicle which therefore provide a double feedback to the car.
The most common are installed on the edge of the lanes to warn the driver when he is leaving the white line who delimits the roadway. Other sound gangs can however be installed in the center of the lane and suggest the driver of slow down. In this second case, sound bands are used to provide the driver with a certain perception of driving speed. A series of sound gangs installed in a progressive way can cause such a noise to make the driver perceived specifically which is traveling at too high a speed and, consequently, induce him to slow down. This trick is used above all in the most dangerous crossings.
The same result can also be obtained with i Optical slowdownsthat is, the white stripes that we find in the lane (sometimes with growing width along the direction of travel and decreasing distance). These have the same effect as the sound bands but act by creating an optical illusion rather than a noise.
In Italy, sound bands are included in the reporting systems included in the rules on horizontal signs and vertical (articles 40-44 of the Highway Code) and are specified in article 179 of the implementation regulation. Since the law does not regulate its shape or material but, rather, the operation exist of different types. The important thing is that they work.
Types of sound gangs
Beyond shapes, colors, heights or depths, we can divide the sound bands into two main families: those obtained from the road surface itself (and, therefore, in asphalt) and those installed as extra elements.
The sound gangs obtained from an existing road surface are made with a car that goes to scratch the asphalt creating furrows. Alternatively, if it is a newly paved road, the depressions are created with machines with shaped wheels that pass on the asphalt and print it, leaving the furrows.
An alternative is the application of elements added to the road surface that are in relieflike little ones bump. These elements must be well adherent to the road flooring and are often integrated with reflective devices that reflect the light. Usually these sound gangs are strips in high resistance plastics, made with mixtures of resin and elastomers which make the product sufficiently elastic and impact resistant. There are several types on the market because the important thing is the result they feel, not their composition; In any case, if the sound bands are prefabricated, they must be approved by the Ministry of Public Works.
Do sound gangs work? Road safety data
Sound bands already exist from 70s And they have been tested on several occasions. Studies show that sound gangs provide the driver with information useful especially in conditions of poor visibility. It is not possible to scientificly establish theuniversal effectiveness sound gangs because each study is carried out on a certain type of road or crossroads and with a certain type of sound bands positioned in a certain way along the stretch of road analyzed. For this reason there are many investigations on the applications of sound gangs in different contexts in scientific literature.
For example, in Louisiana between 2010 and 2012, monthly observations were conducted on 312 motorway segments for a total of 2050 km Length, along which sound bands have been installed along the central line that divides the lanes by direction of travel. Comparing the time interval 2005-2012 (pre-intervention period) and the time interval 2013-2017 (post-intervention period), there is a total reduction of the 17.75% of accidents.
The motorway in Hungary which plays thanks to the sound gangs
The noise produced by the sound bands can also be transformed into one melody. It happened in Hungary, where the galvanizing of the road surface was made in such a way to generate a song when the vehicle passes over it. Only if the speed limit of 80 km/h And the right is held on the roadway, the tires that pass on the sound bands reproduce the Hungarian popular song Érik in Szőlő (“The grapes are maturing”).
