The problem of forming the distribution network results from the need to harmonize the characteristics of efficiency and efficacy of the supply chain with the corporate competition strategy. In this sense the possibility of optimising the distribution network has been presented (on a mathematical model) by applying the logistic outsourcing. The optimisation has been carried out using MS Excel software tools Solver. The results of the analysis have shown that possibilities for the reduction of distribution costs need to be searched for primarily in the domain of transport, in the target segment of the distribution network. The improvement elements have been achieved by outsourcing part of the supply chain, i.e. by introducing the cross-docking system which is managed by the external supplier of the logistic services. Quantitative changes, apart from the redistribution of the traffic of logistic and distribution centres and the reduction of logistic costs, have been reflected also in the geographical arrangement of distribution. The logistic outsourcing had dominant impact on the formation of the distribution network. KEY WORDS: distribution network, optimisation, logistic outsourcing

By adjusting the maintenance approach towards the significant components of ship’s engines and equipment, through the use of operational data from the ship machinery’s daily reports, higher operability and navigation safety can be achieved. The proposed maintenance adjustment model consists of an operation data analysis and risk analysis. The risk analysis comprises the definition of the upper and the lower risk criterion, as well as the definition of a risk index. If the risk index is higher than the lower risk criterion, the component is significant, while it is not significant and has an acceptable risk index if the risk index is lower than the lower risk criterion. For each significant component with a risk index found to be “unacceptable” or “undesirable”, an efficient maintenance policy needs to be adopted. The assessment of the proposed model is based on data regarding the power engine original operation throughout a 13-year period. The results of engine failure examinations reveal that the exhaust valve is the most vulnerable component with the highest rate of failure. For this reason the proposed model of adjusting the maintenance approach has been tested on the exhaust valve sample. It is suggested that the efforts to achieve higher ship operability and navigation safety should go in the direction of periodical adjustments of the maintenance approach i.e. choosing an efficient maintenance policy by reducing the risk indices of the significant engine components. KEY WORDS: maintenance adjustment approach, risk analysis, risk index, lower risk criterion, upper risk criterion, significant components, ship navigation

Pedestrian crossings are the critical points in the traffic network that need to enable pedestrians to safely cross the road. The safety level depends on the type of pedestrian crossing. The differences between individual types of pedestrian crossings can be noted also in relation to other criteria such as the price, energy, environmental impact, accessibility, etc. Besides, various groups of users assess the quality service differently, even when this refers to the same type of pedestrian crossing. Therefore, optimal solution of a pedestrian crossing has to be selected based on a comprehensive and rational analysis and application of adequate software tools. The selection methodology of an optimal pedestrian crossing is defined using a multi-criteria analysis. In order to view the problem as a whole, four scenarios of evaluating alternatives are foreseen. Four different groups of stakeholders: traffic experts, investors, groups of persons with disabilities and healthy persons (persons not included in the previous three stakeholder groups), who use a pedestrian crossing (according to different age, disability, perception of personal safety, etc.), assessed the importance of the offered criteria. Different groups of users have different preferences in relation to individual groups of criteria, depending on their interests and needs. One group finds the criterion of pedestrian safety the most important one, others think that finances are most important (the cost of construction), some think that accessibility is the most important issue, etc. The solutions obtained in this manner provide insight into the advantages and drawbacks of individual versions. This makes it easier for the decision-makers to select only one variant / alternative from a group of the offered solutions in compliance with the defined criteria and sub-criteria with the aim of defining an optimal pedestrian crossing for a certain spatial and traffic location. KEY WORDS: pedestrian crossing, multi-criteria decision-making, analytical hierarchy process

An appropriately designed motorway access control can decrease the total travel time spent in the system up to 30% and consequently increase the merging operations safety. To date, implemented traffic responsive motorway access control systems have been of local or regulatory type and not truly adaptive in the real sense of the meaning. Hence, traffic flow can be influenced positively by numerous intelligent transportation system (ITS) techniques. In this paper a contemporary approach is presented. It considers the design philosophy of an optimal and adaptive closed-loop multiple motorway access control strategy. The methodology proposed uses the artificial intelligence technique - known as reinforcement learning (RL) with multiple agents, and applies the Q-learning algorithm. One segment of the motorway network with three lanes in each direction and three motorway entries was designed. The detectors and traffic signals were placed at the entries (ramps). Traffic flows and traffic occupancy on the main line as well as the traffic demand on the motorway entries were taken as input model variables. The output variables referred to the travel speed on the corridor, the total travel time, and the total stop time. VISSIM micro-simulator and direct programming of the simulator functions were used in order to implement the RL technique. The peak hour was chosen for the time of simulation. The model was tested in two phases. Its effectiveness was compared to ALINEA. It was observed that the proposed strategy was capable of responding both to dynamic sensory inputs from the environment and to dynamically changing environment. The model of the environment and supervision were not required. The control policy changed as response to the inherent system characteristic changes. It was confirmed that the strategy was truly adaptive and real-time responsive to the traffic demand on the corridor. KEY WORDS: motorway access, traffic flows, control, strategy, artificial intelligence, Q-Learning, simulation

Advanced automatic traffic control systems and various other ITS (Intelligent Transport Systems) applications and services rely on real-time information from the traffic system. This paper presents the overview and general functions of different information sources which provide real-time information that are used or could be used in ITS. The objective is to formally define the quality of information sources suitable for ITS based on formal models of the traffic system and information sources. The definition of quality encompasses these essential factors: traffic system information that exists or may be requested, user requirements and attributes that describe the information sources. This provides the framework and guidelines for the evaluation of information sources that accounts for relevant factors that influence their selection for specific ITS applications. KEY WORDS: information source, information source quality, Intelligent Transport Systems (ITS), automatic traffic control

The transportation of hazardous goods represents an economic activity whose consequences can have serious impact on the safety of transportation, the environment and human health. With the aim of reviewing the elements that affect the activity, this article presents a model for the transportation of hazardous goods of which, generally, there are two forms: the theoretical model for the transportation of hazardous goods, which represents the goal for the establishment of relations on the transportation of hazardous goods services market; and the real model for the transportation of hazardous goods, which represents an adaptation of the theoretical model to the status in a specific localised region. The research, which was conducted as part of the principal author’s Ph.D. thesis, illustrates the exceptional influence of the society changes within a specific country. The theoretical model for the road transportation of hazardous goods is transposed into the real transportation services environment in Slovenia and it presents its transition and incorporation into the common EU transportation service market. KEY WORDS: transportation policy, model of the road transportation of hazardous goods

The density of navigation in the world waterways is considerable, especially because it is more profitable, when compared to other forms of transport. In this paper the authors propose new measures for security protection of inland waterways and of ships and ports in inland navigation. Because of various kinds of threats in inland waterways navigation it is proposed to develop the International Ship and Port facility Security Code (ISPS) code suited to such navigation. Therefore the working title of the document is proposed as International Ship and Port Facility Security Code in Inland Waterways (ISPSIW). KEY WORDS: safety, threats, protection, inland navigation

This paper describes the trends towards green logistics in global aspect and challenges of adopting green logistics in the region of Southeast Europe. Modern logistics with supply chain management is experiencing a period of important evolution. From reversible logistics, we came to green logistics, which is a wider concept of environmentally friendly thinking. Reverse logistics includes processes of movements and transportation of waste from users to recycling plants; meanwhile, green logistics deals also with environmental issues such as pollution and environmental degradation caused by improper logistics processes and utilisation of old and environmentally unfriendly transport technology. The case of Southeast Europe was analysed, and in this context, a development model for green logistics implementation was proposed. A vast number of different challenges in the logistics sector are still open in this region; therefore, systematic analyses and proposals should be subject of additional scientific work in the logistics sector. All parties, including manufacturing industry, logistics providers and governments should take an active part in such researches, as the pressure from green thinking will become even stronger in the coming period. KEY WORDS: reverse logistics, green logistics, logistics providers, Southeast Europe, green logistics model