The aim of this paper is to explore the relationship between the features of Longer Combination Vehicles (LCVs) and road safety issues. LCVs are road vehicles that exceed dimensions of a typical or standard heavy truck-trailer or tractor-semitrailer combination vehicles in length or length and weight. The systematization of LCVs is done. Several areas, which are likely to benefit through LCVs, are listed and described. The analysis of literature review is made in the areas where additional problems may be encountered using LCVs. Several engineering factors such as resistance to rollover, swept-path parameters, vehicle capabilities of accelerating and maintaining speed as well as braking performance are analyzed. Several research projects on traffic accident analysis have been looked through to compare their conclusions about traffic safety of LCVs. The analysis of discussions related to LCVs traffic safety issues is provided. Some transportation experts and community groups have conflicting views about road safety issues of LCVs. The opinions and related arguments of both parties are discussed in this paper. Several technical improvements in designing LCVs and the importance of driver training programs are described.

ISO 9001 quality management systems is one of globally well-known standards developed by the International Organization for Standardization (ISO). It is widely implemented in different organisations, regardless of their size class and sector of activity. The aim of this study is to collect and analyse information on mechanical engineering enterprises by size classes in Latvia that have been certified in conformity with ISO 9001 requirements. This study presents findings from the research focused on mechanical engineering. Therefore, an overview of the most popular management system standard in the mechanical engineering sector has been done. A comparative analysis has been applied in order to determine the proportion of enterprises with quality management systems certified in accordance with the ISO 9001 standard by industrial sector in Latvia and worldwide. The expected research outcome is a distribution of mechanical engineering enterprises by size classes (micro-, small-, medium-sized and large-scale enterprises) in Latvia certified with ISO 9001.

The existing standards for surface roughness cover only two dimensions, while in reality this is three-dimensional (3D). In particular, the 3D surface roughness parameters are important for solving the contact surface mechanics problems as related to the accuracy of 3D surface roughness characteristics. One of the most important factors for determination of 3D characteristics is the number of data points (NDP) on the x-and y-axes (i.e. in cut-off length). The NDP has a profound effect on the accuracy of measurement results, measuring time and volume of the output data (especially along the y-axis, where the NDP is identical to the number of parallel profiles). At a too small NDP the results will be incorrect and with too broad scatter, while a too large NDP -though not enlarging the range of basic information -considerably increases the measuring time. Therefore, the aim of the work was to find the optimal NDP for such surface processing methods as grinding, spark erosion and shot methods of surface treatment.

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