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Materials used to reduce dustiness on gravel roads affect both the gravel road surfacing and the neighbouring vegetation. Materials used to reduce dustiness may access vegetation directly (when sprayed on gravel roads) and indirectly (when leached out by precipitation). The investigation examined a new substance, the aqueous solution Safecote (of different concentrations) and its mixtures with calcium chloride. 10%, 20% and 30% concentrations of Safecote and 36.5% of calcium chloride were used. The mixture ratio was 1:1 by volume. The investigation addressed the impact of the applied solutions on the length and viability of the above-ground part of plants. The timothy grass, white clover and crimson clover species of grass vegetation were selected for the investigation. The choice was determined by the fact that these species frequently grow in pastures by gravel roads. As it was determined during the investigation the viability of the selected plants in non-contaminated soil was 85-89%, in soil contaminated with dust reducing agent was 67-88% using solution Safecote, and 0-1% when applying mixtures of solutions. After 6 weeks of growth the length of above-ground part was 6.41-8.57 cm in uncontaminated soil, 4.22-8.18 cm in soil contaminated with Safecote solution and 0.00-2.07 cm in soil contaminated with the mixture.

Granular shoulder is an important element of road system. One can frequently notice shoulders rutting, edge breakage, unconformity of cross-section to the norms that could be caused by wind and water-generated erosion. These problems directly affect the drivers, influences their behaviour on the road and traffic safety. Therefore, a constant maintenance of road shoulders is necessary. Investigations of the Lithuanian gravel road network showed that the lowvolume roads with gravel surfacing do not correspond to the current standards and the change in their performance due to climatic conditions, traffic volume and the materials used for the structures have a large influence not only on traffic safety but also on traffic conditions. It is very important for the road shoulders to improve traffic safety, to prevent road carriageway edges from degradation, to serve for emergency parking and for the installation of guardrails, warning and informatory signs. Since shoulder deformations are caused by the deformations in the subgrade and its slopes, a properly prepared and erected subgrade should be provided with the shoulder of corresponding structure where inadmissible deformations would not occur. Defects in the low-volume road pavement occur when gravel of unsuitable composition is used for the shoulder pavement, the structure is of insufficient thickness and strength, the top of the subgrade becomes damp due to the lack of proper drainage or road maintenance is of unsatisfactory level. It is very important for the shoulders of low-volume roads to use a proper material for increasing the structural strength of the shoulder and preventing it from defects.

Vehicles in motion on roads are the main source of noise in the environment. The noise in a car is created by structural noises from car construction, originated from vibrations in an engine, cabin, silencer, wheels and tires. Traffic noise flow depends on its intensity, motion speed, flow composition and extent, quality of the road pavement and build-up of the area along the road. This paper contains research on motor transport produced noise levels on roads of regional signifi cance with gravel and asphalt pavement in Molėtai district. The level of motor transport produced noise was measured in wintertime and summertime at the chosen typical locations considering the nature of the asphalt and gravel road pavement and diff erent landscape morphology forests, topography roughness, open area, upslope, downslope, etc. Also, research of noise level dependence on car speed was performed from 50 km/h to 70 km/h. It was determined during the study that noise level produced by a car moving at a speed of 50 km/h on a road with gravel pavement is higher by 4 dBA than that on a road with asphalt pavement. Upon moving away from the noise source by 50 m, the level of noise decreases by 12 dBA in woodland open areas and by 16 dBA. As car speed increases from 40 km/h to 50 km/h in wintertime, the level of noise rises by 2 dBA. In summertime, as car speed increases from 50 km/h to 70 km/h, the noise level rises by 5 dBA. These differences are due to the presence of ice and snow on the road in winter. Noise depends on physical properties of tires, type of pavement, car vibrations and in particular on pavement roughness.