In recent years, the development of the GIS-T (Geographic Information System for Transportation) applications has gained much attention, providing the transportation planners and managers with in-depth knowledge to achieve better decisions. Needless to say, developing a successful GIS for transportation applications is highly dependent on the design of a well-structured data model. Dynamic segmentation (DS) data model is a popular one being used more and more for different GIS-T analyses, serving as a data model that splits linear features into new set of segments wherever its attributes change. In most cases, the sets of segments presenting a particular attribute change frequently. Transportation managers place great importance on having regular update and revision of segmented data to ensure correct and precise decisions are made. However, updating the segmented data manually is a difficult task and a time-consuming process to do, demanding an automatic approach. To alleviate this, the present study describes a rule-based method using topological concept to simply update road segments and replace the manual tasks that users are to carry out. The proposed approach was employed and implemented on real road network data of the City of Tehran provided by the Road Maintenance and Transportation Organization (RMTO) of Iran. The practical results demonstrated that the time, cost, human-type errors, and complexity involved in update tasks are all reduced. KEYWORDS: GIS-T, dynamic segmentation, segment, automatic update, change type, rule

In recent years the providers of logistic services are under big pressure to lower their expenses and improve their quality. One way of accomplishing this task is the centralization of logistic activities. The paper presents possible methods for restructuring the distribution network on the case of Slovak Post p.l.c. By reducing the number of centres for distribution and by creating larger centres one can expect improvement in the process efficiency. There is no simple method to find the optimal distribution network. One possible way to tackle this problem is to use aggregation methods to group customers on the micro and macro levels. Several aggregation methods, including two new ones are presented and compared for the centres’ and delivery districts. New measurements for the quality of aggregation are created and tested on real data using all the discussed aggregation methods. KEY WORDS: network creation, aggregation, quantitative methods, fuzzy logic, distribution districts

Road traffic safety is a complex system which combines movement of entities in precisely determined space and time dimension. Each of the entities, with their different properties, sets different requirements to road traffic system, including also other entities. Due to the large number of entities and their characteristic requirements, their interaction results in extremely complex relations which determine the behaviour of the road traffic system. The entities are combined according to their common features into certain groups, the movements of which usually result in conflicts. In such situations it is necessary to ensure the movement of a group of entities. This method of insurance necessarily creates negative consequences for all the entities that participate in road traffic system. In order to mitigate as much as possible these consequences, it is necessary to find an adequate method of optimising road traffic system according to a given criterion. The paper uses the results of the analysis of more than 100 road traffic system models and presents the methodology of determining the level of their interconnection. The level of influence of the basic traffic values on the final effect, i.e. the possibility of optimising signal-controlled intersections has been found and described. KEYWORDS: traffic flow, signalized intersection, pretimedsystem, optimization, 2-phase system, 4-phase system, volume-to-capacity, lost time

This paper deals with the application of System dynamics and Chaos theory in shipping using the example of freight rate forming. The development of new technologies, changes in structure and conditions, information accessibility, etc. are only some of the factors that intensify changes in freight rate forming in shipping. Therefore, shipping environment is becoming increasingly complex and dynamic. System dynamics seems to be a tool very suited for modelling of strategic and operational behaviour in shipping business. Due to the complex behaviour of these systems, chaos theory can also help in modelling of processes in shipping. The basic feature of chaotic systems is fine sensitivity in conditions at the beginning, when small change in input value may cause great changes in output values. By applying its concepts to the business process, as well as in freight rate forming in shipping, it prepares the business systems for quick response to the changes in the environment. KEY WORDS: chaos theory, shipping, freight rate, system dynamics

While operating a locomotive or a railcar the engine drivers are exposed to the action of several simultaneous factors of disturbances from the traffic environment, and therefore their reliability and safety are reduced. The human-determined physical, sensor and cognitive factors are not only the attributes of the engine driver, but also include influences from the traffic environment, due to the interaction in the “engine driver – traffic means – traffic environment” system. Traffic environment is defined in such a way that, among other things, it includes also the working environment of the drivers cab and the recent traffic situation. The action of factors of temporary subjective disturbances and/or permanent psychological and physiological changes, depend not only on the individual endurance of engine drivers, but also significantly on the type of locomotive or railcar operated by the engine driver, as well as on the fact whether the traffic is intended for the transport of passengers and/or freight, or a shunting engine is involved. The ergo-assessment based on a survey of 50 respondents yielded the final results that are almost identical to the results of ergo-assessment obtained during the formation of the methodology of cognitive ergo-assessment on a sample of 31 respondents. In both cases the surveyed respondents were engine drivers who in practice operate all types of locomotives and railcars, who have acquired engine driver secondary school qualifications and have passed vocational testing for all types of locomotives and railcars. Systemic ergo-assessment of the intensity of the overall psychophysical effort is possible by introducing the index of importance which is used in case of all engine drivers to integrally and equally recognise also the influence of the percentage of occurrence of a certain factor of subjective disturbance and influence of the average assessment of the subjective disturbance intensity, thus allowing an insight into the structure of a system of simultaneous ergo-assessment factors and isolation of ten dominant ergo-assessment factors. Partial cognitive ergo-assessment and inter-comparison of the intensity of subjective disturbances have indicated the types of locomotives and/or railcar compositions in which the maximum partial intensity of disturbance is due to the following factors regarding the working ambient of the drivers cab: visibility, intensity of the difficulty of operation, and intensity of disturbance of the audible traffic noise. KEY WORDS: traffic environment, cognitive ergo-assessment, dominant factors of subjective disturbances, assessment parameters, safety and reliability

The demand for parking services is not a constant one, but rather varies from minimum to maximum. The range between the maximum and minimum demands and the dynamics of changes are the basic factor influencing the required size of the parking area capacity and the respective financial effects. The objective of this paper is to demonstrate that the queuing theory can be implemented in defining the optimal number of serving places (ramps) and the required capacity (number of parking spaces) in controlled access parking areas and that the established model can serve in business decision-making in respect to planning and development of the parking area capacity. The presented model has been verified in the example of the “Delta” parking area in the City of Rijeka but this model is particularly valuable as it can be implemented in any controlled access parking areas, i.e., parking areas with toll-bars under current or any other changed future conditions. KEY WORDS: planning of parking area capacities, optimal parking area capacity, queuing theory, parking area as a queuing system

The purpose of this paper is to define factors that influence the emergence of induced i.e. generated traffic for experts involved in highway feasibility studies. An explanation of the practical methods for forecasting generated traffic is done by reviewing international experiences in the relevant literature. Also, the idea underlying this paper is to explain the different treatments of generated traffic in evaluating highway projects with no tolls, which is based on socio-economic aspects versus the evaluation of highway projects with tolls, which is based on financial aspects. Finally, we propose that since it is hard to measure the economic benefits from indirect effects (in the evaluation of socio-economic aspects) the evaluators could determine the economic benefits of the generated traffic using the same procedure as for normal traffic. KEYWORDS: induced traffic (generated traffic), normal traffic, coefficient of elasticity, time savings, vehicle operating cost (VOC) savings, the economic surplus

Big cities in the world are burdened by heavy traffic and all the resulting negative consequences. A partial solution of this problem is achieved by the introduction of high-quality public urban transport of passengers that enables faster and more efficient transport. Since the introduction of individual forms of public urban transport depends on several factors, such as economic, traffic, environmental and technical ones, the problem is often a very complex one. The implementation of trolleybuses represents one of the forms of passenger transportation in public urban transport. It is the most favourable electrical vehicle for public urban transport when the implementation of a rail system is not affordable. Looking through history, the trolleybus has experienced significant changes in the implementation, in a large number of world urban environments. This paper points out the unjustifiable neglect of trolleybus in the implementation for the public urban transport and the renewed increase in the interest for its implementation. The advantages and drawbacks of the trolleybus are listed in relation to buses, as well as the reasons due to which some cities in the world are introducing it or increasing its implementation. The paper also emphasises and provides arguments of the ecological and energy advantages of trolleybuses in relation to buses as crucial in advanced public urban transport of passengers. Also, advanced technical solutions are pointed out that contribute to safer, faster and more comfortable transport of passengers. KEY WORDS: trolleybus, bus, public urban transport, environment, economics