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Sanja Bauk, Marinko Aleksić, Špiro Ivošević
2011 (Vol 23), Issue 6

This paper deals with two different approaches in modelling corrosion wastage over the fuel tanks’ structures on the example of ten aged bulk carriers. The first applied method might be treated as a short-term, rather random oriented one, and it is based on the Monte Carlo simulation technique. This technique has been used in creating an appropriate predictive model for the characteristic steel damages over the bulk carriers’ fuel tanks caused by general corrosion in relatively short time interval of two years, within the period between the 5th and the 25th year of the bulks’ operational life. The second employed method might be treated as a long-term one, and it is based on a Weibull distribution analysis. The purpose of these analyses is optimal assessing of the average corrosion losses for the bulk carriers’ fuel tanks areas at different points of time during the whole exploitation cycle, within the ultimate goal of raising the structural stability and safety of bulk carriers in operation.

KEY WORDS: bulk carriers, fuel tanks, corrosion wastage, Monte Carlo simulation, Weibull probability analysis


Zdravko Toš, Tomislav Josip Mlinarić, Hrvoje Haramina
2011 (Vol 23), Issue 6
The increase of demand for transport service in rail commuter traffic stipulates higher ratio of consumed infrastructure capacity. In this method of traffic flow even minor deviations from the planned timetable can have negative influence on its stability, and this can result in major reduction of the quality of transport service. This research has defined the commuter rail traffic management system model with the application of real-time timetable rescheduling. It understands the application of the decision support system during the procedure of adjusting the timetable to the real condition in traffic in the form of genetic algorithm defined on the basis of the valid rules for the train and traffic control. Besides, this model in all the commuter trains understands the existence of the driver advisory system which is based on the algorithm for determination of the most favourable running regime with the aim of saving in energy consumption. The paper proves that by applying the proposed model the commuter rail traffic can be improved regarding the increase of the timetable stability and energy-efficient train operation. KEY WORDS: rail traffic management, genetic algorithm, energy efficient timetabling and train operation

Renato Ivče, Irena Jurdana, Robert Mohović
2011 (Vol 23), Issue 6
The accuracy of measuring mass of loaded or discharged cargo by draft survey mass measuring method varies due to both systematic and accidental errors. The paper analyzes an error of draft readings on the calculated quarter mean draft, displacement based on the calculated quarter mean draft and the final displacement. By analyzing this problem, the authors have reached the conclusion that the influence of an error made in draft readings can be significant, especially on the draft marks amidships. Optical fibre technology has been suggested as a new option for draft readings. In this paper, the authors propose a liquid level optical sensor for measuring the sea level in the sounding pipe. Draft readings obtained by optical sensors will be entered into ships’ navigational system and load master. KEY WORDS: ship’s draft, error of draft readings, optical fibre technology, liquid level optical sensors.

Zvonimir Majić, Irena Jukić, Tomislav Vuk, Stanislav Pavlin
2011 (Vol 23), Issue 6
In air freight industry, blood samples are classified as time and temperature sensitive biologically produced pharmaceuticals. To determine the level of influence that the handling processes and air transportation have on blood sample quality, a research has been conducted through transportation of whole blood samples on two European scheduled routes. Two shipping models were defined: the standard one without defined transportation temperature regime and the controlled one, where transportation is conducted under appropriate temperature regime. The blood samples were packed and transported respecting all relevant national and international regulations. The analysis was conducted and the results compared to control sample kept in the laboratory. Significant changes were identified on all components analyzed after crosschecking with the control sample. KEY WORDS: regulatory issues, blood sample quality, shipping model, packaging instruction, temperature profiles

Siniša Vilke, Livia Šantić, Matija Glad
2011 (Vol 23), Issue 6
This paper presents and analyses the redefined Rijeka railway junction. The redefined concept of the Rijeka railroad hub in the context of port and railway interdependence dictates the need to find the accommodation of cargo transport to peripheral locations such as: Krasica, Kukuljanovo, Bakar, Ivani, Bršica and capacity for the island of Krk, while passenger transport would be implemented in the urban area. The most important projects related to Rijeka rail transport system are the construction of a new line of high efficiency between Zagreb and Rijeka, and a new railroad through the tunnel of Učka which will link the ports of Rijeka, Koper and Trieste. Together with the reconstruction of cargo stations Rijeka and Brajdica, an extension of the other tracks on the railroads Škrljevo-Rijeka and Rijeka-Opatija/Matulji should be performed as well as the construction of Krasica, Ivani, Tijani and Vrgljevo stations. The construction includes a multipurpose bridge to the Island of Krk and a railway line to the new container terminal as well as the new railway bypass to “elevation 200”. KEY WORDS: Rijeka railway junction, railway transport system, railway transport, Port of Rijeka

Toni Bielić, Sadko Mandžuka, Vinko Tomas
2011 (Vol 23), Issue 6
The paper investigates conditions and circumstances of the occurrence of emergencies during ship exploitation. The concept and different forms of emergencies are defined while conditions of their occurrence are simulated, as well as possible modes of prevention of their occurrence or development. On the basis of the results of the investigation covering 240 professional seamen an appropriate organisational algorithm of participative ship management is defined as foundation for the application of the management algorithm in emergencies. On this basis the method of Risk and Hazard Assessment is applied. Also, the algorithm of Decision Making Process is derived from the related investigations. The proposed algorithm is not based only on the organisational presuppositions of participative management but also on complex human relationships as well as acting in stressful circumstances through all the phases of emergencies. The appropriate decision support system to help decision-makers during the emergencies is described. KEY WORDS: emergencies, algorithm, team work, participative management, hierarchical acting, scenario, communication

Stjepan Lakušić, Davor Brčić, Višnja Tkalčević Lakušić
2011 (Vol 23), Issue 6
Urban road infrastructure is daily burdened by heavy traffic volume. Pavement structure roughness observations are significantly more difficult in urban agglomerations than on roads in unpopulated areas. Roughness, expressed by IRI (International Roughness Index), directly affects the quality and safety of road traffic. Within the framework of the pavement management in relation to safety and the achievement of the best possible ride comfort, it is very important to foresee when a road should be reconstructed. The method for quality evaluations of safety and ride comfort on urban roads presented in this paper is based on vehicle vibrations measurements. In the article, measuring of vehicle vibrations was performed on the main urban roads in Zagreb (Croatia). Measurements covered roads with different pavement surface roughness. This method can be simply and very easily used in pavement management aimed at achieving road safety and better ride comfort. The results of measurements according to this method could be used by traffic and civil engineering experts as an indication for the roads that require reconstruction or maintenance. KEY WORDS: urban roads, traffic flow, safety, vehicle vibrations, road surface roughness (IRI)

Ines Kolanović, Čedomir Dundović, Alen Jugović
2011 (Vol 23), Issue 6
This port service quality study is an important precondition for an efficient development of port industry and traffic system as a whole. It is due to the complexity of any port, as a system consisting of a large number of stakeholders rendering services to customers with various requirements, that a unique set of port service quality indices has been still missing. For this reason, the paper explains the port service quality concept in compliance with stakeholders and their requirements within the context of port service quality. The aim of the paper is to present a proposal for a customer-based port service quality model based on empirical study and its reliability testing on a selected sample. The proposed model is defined by five factors and fits satisfactorily into the obtained poll questionnaire results. The statistical data processing package SPSS 16.0 and the LISREL 8.54 programme were used in the study. KEY WORDS: port service, customer, model, factor analysis

Pavle Gladović, Vladimir Popović, Velibor Peulić
2011 (Vol 23), Issue 6
In all the cities of Serbia that have organized systems of public mass passenger transport (PMPT), over the past several years more and more private transport companies are being included in the network of city and suburban transportation lines. The inclusion of private transport companies in the PMPT system via public tenders should be preceded by the procedure of calculation of the realistic income and system functioning expenses in order to establish possible balances of needs for City Budget subsidies, as well as the elements on Contract of entrusting this vital communal activity of every city. The new principle for determining the total cost of PMPT system functioning, based on line difficulty ranking, has been presented in this paper. KEY WORDS: expenditure model, price, PMPT system, line, exploitation parameters, evaluation, line rank

Yong Cui, Ullrich Martin
2011 (Vol 23), Issue 6
Simulation methods are widely used in railway planning and operation. However, at the moment there are no applicable solutions in the process simulation for a smooth transition among different infrastructure levels on the basis of a unified structure with consistent algorithm. In this paper, a multi-scale simulation model is designed with consideration of the level of detail of the investigated infrastructure model and the homogeneity of the processes running in the simulation model. A comprehensive and synthesized view of railway planning and operation is therefore obtained. Within the multi-scale simulation model, railway planning and operation processes can be simulated, evaluated and optimized consistently. KEY WORDS: railway planning, simulation, multi-scale, aggregation, discrete scaling, continuous scaling, homogenous process, inhomogeneous process

Andrija Vidović, Sanja Steiner, Igor Štimac
2011 (Vol 23), Issue 6
The liberalization of the aviation market has enabled low-cost airlines to take over a significant share in the aviation market. Benefits of low-cost models are multiple, both for passengers and for secondary and regional airports, which were neglected in the past and which record significant inflow of passengers with the arrival of low-cost airlines. In the structure of the air traffic in the Republic of Croatia in the last ten years, there has been a progressive growth of foreign low-cost airline operations, which suggests a potential for the operation of a Croatian low-cost airline. This paper defines the criteria applicable to modelling of a low-cost airline in the Republic of Croatia in the relevant context of fleet management, route networking and operator’s processes in traffic technology. It analyzes the dynamics of low-cost airlines operations in the structure of air traffic in Croatia and the impact of traffic on the status of airports and the national operator. KEY WORDS: low-cost airline, traditional airline, airport, route network, fleet management

Libor Beneš, Rudolf Kaloč
2011 (Vol 23), Issue 6
The paper provides a description of tribological aspects and the latest type of laboratory equipment which is expected to offer particular new knowledge in the field of railway wheel - rail contact phenomena diagnostics. The main considerations stated in this work imply that the coefficient of adhesion is among others dependent on contact temperature, and therefore it is possible to theoretically predict the value of the coefficient of adhesion. This fact has not been considered in the theory of adhesive contact so far. The entirely credible prognosis of the studied unfavourable effects is hardly satisfactorily solvable in theory. Hence, the authors present a new testing device by which the predicted effects will be verified. At the same time, the oscillation effect on the state of surface will be observed in the attached formulas. The work also implies that the effects evaluating possible initiations and local degradations of the contact area of railway wheel and rail are closely bound to the tribological effects that are comprehended here as dynamic processes. KEY WORDS: contact fatigue, railway wheel - rail contact, tribology, safety of transport

Stephan Gollasch, Matej David
2011 (Vol 23), Issue 5
The human-mediated transfer of harmful organisms via shipping, especially via ballast water transport, has raised considerable attention especially in the last decade due to the negative associated impacts. Ballast water sampling is important to assess the compliance with ballast water management requirements (i.e. compliance monitoring). The complexity of ballast water sampling is a result of organism diversity and behaviour which may require different sampling strategies, as well as ship design implications including availability of ballast water sampling points. This paper discusses the ballast water sampling methodologies with emphasis on compliance monitoring by the Port State Control officers according to the International Convention on the Management of Ships’ Ballast Water and Sediments, 2004. KEY WORDS: maritime transport, compliance control, port state control, ballast water sampling, ballast water management

Marko Matulin, Štefica Mrvelj, Niko Jelušić
2011 (Vol 23), Issue 5
The focus of this paper is evaluation of public transport (PT) performances. For this purpose the focus is on quantitative performance attributes of tramway network and two levels of the evaluation analysis are defined – the micro and macro level analysis. The two-level evaluation analysis can be used to solve the problem of ambiguity in conclusions about PT performances. The ambiguity appears when the set of collected data is incomplete, misinterpreted, partially analyzed or when some background impacts are neglected. For each level of analysis a set of performance indicators is defined and their mathematical formulations are presented. The selection of indicators is based on the analysis of expected events on the PT vehicle’s itinerary. The applied data collection methodology, necessary for testing of proposed evaluation approach, is described and the results are presented and discussed. It has been found that for a specific case the two-level evaluation analysis can be important for the control of PT performances and transport planning. KEY WORDS: evaluation, public transport performance, micro and macro level analysis, quality of service

Fatemeh Haghighat
2011 (Vol 23), Issue 5
Road safety is one of the influential factors in reducing road accidents and the resulting injuries and fatalities. The aim of this study is to determine the safety position of the roads of the Bushehr province based on various quantitative and qualitative criteria. For this purpose, a Multi-Criteria Decision Making (MCDM) approach has been utilized. In this approach, first all criteria influencing road safety in the Bushehr province were classified into main and sub-criteria groups and their weights were obtained using Group Analytic Hierarchy Process (GAHP). Then, the rankings of the Bushehr province roads were calculated through the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). The results indicate that during the period of investigation, the roads of Bushehr-Borazjan and Borazjan-Genaveh were the best with minor difference and Deylem-Behbahan road was the worst road of this province. In this regard, the criteria of violations/traffic and road facilities contribute more to the results due to their weights. It is clear that continuous evaluation of road safety will have significant effect on governmental policy-makings for improving roads and safety-related actions. KEY WORDS: Roads Safety Coefficient, quantitative and qualitative criteria, Multi Criteria Decision Making (MCDM), GAHP Technique, TOPSIS Method

Tomaž Tollazzi, Marko Renčelj, Sašo Turnšek
2011 (Vol 23), Issue 5
Recently, many of the foreign traffic-safety analyses point out the low level of traffic safety in multi-lane roundabouts. This problem is resolved in several ways in different countries; however, the solution, whereby the number of conflict points is diminished (e.g. turbo roundabout) has proven to be the most successful. However, the turbo roundabout also has its deficiencies: it has conflict crossing points and larger reconstruction of the existing two-lane roundabout is needed when the turbo roundabout is to be implemented instead of the existing one. In the paper a new type of roundabout has been introduced; the roundabout with “depressed” lanes for right turning (“the flower-roundabout”). Financially speaking, the main advantage of the new type of roundabout is that it can be implemented within the dimensions of the already existing “normal” two-lane roundabout. From the traffic-safety point of view, the main advantage of the new type of roundabout is that it has no crossing conflict points. KEYWORDS: traffic safety, roundabout, turbo roundabout, roundabout with “depressed” lanes for right turn

Tomislav Kljak, Marijan Bolarić, Marijan Binički
2011 (Vol 23), Issue 5
The key hypothesis of the paper is the existence of a particular impact occurring between the development of mobile telecommunications traffic and the development of postal traffic. The objective of the paper is to ascertain the strength of the impact as well as the nature (type) of the impact in the case of the state of the art in the Republic of Croatia. Relevant data have been collected regarding the number of postal services realised (letters and parcels), minutes referring to duration of the voice conversations within, from and towards mobile networks as well as the number of text messages (SMSs) sent. The interrelations between the postal traffic and mobile telecommunications traffic have been determined following the multi-regression linear modelling which has been statistically tested after having been determined. KEY WORDS: postal traffic, multi-regression modelling, mobile telecommunications traffic

Biljana Juričić, Ružica Škurla Babić, Ivana Francetić
2011 (Vol 23), Issue 5
The paper deals with the Zagreb Terminal Airspace capacity. The basic scenario has been modelled using the RAMSPlus simulator and capacity has been calculated by using the WMSE method which takes into account the peak-hour workload based on air traffic controllers’ tasks. The problem of traffic congestion has been analyzed and several case study scenarios have been simulated. The conducted simulations have demonstrated that in the conditions of increased traffic loads (traffic demand amounting to 6% annually) the working technology and the airspace organization of Zagreb Terminal Airspace will become a restricting factor at peak-hour workloads. The new technologies in Zagreb Terminal Airspace (P-RNAV routes and airspace sectorization) will enable the reduction in air-traffic controller’s workload regarding radar vectoring, radio-telephony and coordination tasks. This should increase the airspace capacity and thus enhance the safety and orderly flow of air traffic. KEY WORDS: terminal airspace, capacity, simulation, workload, task, sectorization

Žarko Koboević, Pavao Komadina, Željko Kurtela
2011 (Vol 23), Issue 5
This paper deals with the rules and regulations pertaining to the protection of the marine environment from the pollution by vessel’s sewage. There is an international perspective on legal regulations dealing with this matter, but the sensitive marine environment has not been properly covered. Some maritime countries have set forth their own and more strict regulations to provide for a more efficient protection of their marine environments. Having compared the international legal regulations for the protection of the seas from pollution by vessel’s sewage with the regulations of individual countries that have stricter regulations, a certain similarity has been noticed in some criteria, but also significant differences in some other criteria concerning allowed discharge of treated or untreated waste waters from the vessels. Amendments to the valid legal regulations and establishment of new rules pertaining to the marine environment are of particular importance in order to provide for a more effective protection of the seas from the increasing pollution from vessel’s sewage preventing thus the negative influence onto marine organisms, human health and economy. KEY WORDS: sea pollution, sewage, black water, faecal coliform bacteria, suspended solids, sewage treatment plant, convention

Ádám Török, Árpád Siposs, Ferenc Mészáros
2011 (Vol 23), Issue 5
The main scope of this paper is to present the historical background and the foreseeable future of the Hungarian road tolling. In the introduction the authors have investigated the historical dataset of motorway constructions and analysed the unequal extension of motorway system in time and space. In this article the authors are considering road tolling as an instrument of financing road infrastructure investment and the maintenance and controlling possibilities of traffic flows. KEYWORDS: road transportation, reduction of travel time, positive external effect

Stephan Gollasch, Matej David
2011 (Vol 23), Issue 5
The human-mediated transfer of harmful organisms via shipping, especially via ballast water transport, has raised considerable attention especially in the last decade due to the negative associated impacts. Ballast water sampling is important to assess the compliance with ballast water management requirements (i.e. compliance monitoring). The complexity of ballast water sampling is a result of organism diversity and behaviour which may require different sampling strategies, as well as ship design implications including availability of ballast water sampling points. This paper discusses the ballast water sampling methodologies with emphasis on compliance monitoring by the Port State Control officers according to the International Convention on the Management of Ships’ Ballast Water and Sediments, 2004. KEY WORDS: maritime transport, compliance control, port state control, ballast water sampling, ballast water management

Seyyed Mohammad Sadat Hoseini
2011 (Vol 23), Issue 4
The difficulties of microscopic-level simulation models to accurately reproduce real traffic phenomena stem not only from the complexity of calibration and validation operations, but also from the structural inadequacies of the sub-models themselves. Both of these drawbacks originate from the scant information available on real phenomena because of the difficulty in gathering accurate field data. This paper studies the traffic behaviour of individual drivers utilizing vehicle trajectory data extracted from digital images collected from freeways in Iran. These data are used to evaluate the four proposed microscopic traffic models. One of the models is based on the traffic regulations in Iran and the three others are probabilistic models that use a decision factor for calculating the probability of choosing a position on the freeway by a driver. The decision factors for three probabilistic models are increasing speed, decreasing risk of collision, and increasing speed combined with decreasing risk of collision. The models are simulated by a cellular automata simulator and compared with the real data. It is shown that the model based on driving regulations is not valid, but that other models appear useful for predicting the driver’s behaviour on freeway segments in Iran during noncongested conditions.

Sergej Težak, Ratko Zelenika, Drago Sever
2011 (Vol 23), Issue 4
The cableway transport system is very important for the Slovenian tourist economy. Within the Slovene transport system, the cableway transport subsystem has a specific role because it allows and ensures access to regions which are difficult to access or completely inaccessible by other transport subsystems owing to the configuration of the area. The quality and development of transport services are directly linked to the introduction of new cableways. New technical achievements, which are nowadays used in cableways, all provide greater capacity and higher speed of cableways, which, however, results in their higher maintenance and exploitation costs. The cableway transport system is being developed in Slovenia, but not on principles of sustainable development. This paper presents a model of sustainable growth and development of the cableway transport system in Slovenia based on which it is possible to determine assumptions for future growth so that the Slovene cableway transport system would approach standards of such highly developed systems. The new model includes ten essential elements of this system for which growth rates were calculated.

Dejan Dragan, Tomaž Kramberger, Martin Lipičnik
2011 (Vol 23), Issue 4
The paper addresses the problem of optimal bus stop allocation. The aim is to achieve reduction of costs on account of appropriate re-design of the process of obligatory transportation of children from their homes to the corresponding schools in the Laško municipality. The proposed algorithm relies on optimization based on the Monte Carlo simulation procedure. The number of calculated bus stops is required to be minimal possible, which can still assure maximal service area within the prescribed radius, while keeping the minimal walking distances pupils have to go across from their homes to the nearest bus stop and vice versa. The main issues of the proposed algorithm are emphasised and the working mechanism is explained. The presentation of calculated results is given and comparison with some other existing algorithms is provided. The positions of the calculated bus stops are going to be used for the purpose of physical bus stops implementation in order to decrease the current transportation costs.

Darko Babić, Anđelko Šćukanec, Kristijan Rogic
2011 (Vol 23), Issue 4
Logistics and distribution centres represent very significant infrastructure elements of the macro-logistic system. The creation of the logistics and distribution centres and their connection into a wide (global) network have resulted in the creation of conditions for an adequate distribution of labour and significant increase in the productivity of all the logistics elements and processes, noting that the logistics and distribution centres in this concept have a superregional significance. This paper represents the summary (results) of the research that was carried out on a large number of logistics and distribution centres with the aim of considering the complexity and the issues related to the logistics and distribution centres and the distribution network, their elements and action of the subsystems according to the following criteria: spatial, technical, technological, and organizational, with the aim of defining the categorisation model of the logistics and distribution centres. The analysis of the selected data collected during the research has resulted in defining of the categorisation model of the logistics and distribution centres which foresees six categories. Each of the foreseen categories has been defined according to the set model by the mentioned traffic, technical and technological, and organisational characteristics and the level of service. This is precisely where the application of the categorisation model of the logistics and distribution centres can be found, which will define the relevant categories of the centres applicable in the creation of effective distribution

Ivana Ćavar, Zvonko Kavran, Marjana Petrović
2011 (Vol 23), Issue 4
Official road classification is used for general purposes but for deep traffic analysis this classification is not sufficient. Today there are efficient ways to collect large amounts of data from multiple sources that can be used for different causes. These large amounts of data cannot be analysed with traditional methods and new state-of-the-art algorithms should be used. The paper presents the methodology for urban road classification based on GPS (Global Positioning System) vehicle tracks and data on infrastructural characteristics of road subsegments. The process of defining road categories includes data collection and analysis, data cleansing and fusion, multiple regression, principal component analysis (PCA) as well as cross-validation and k-nearest neighbour (kNN) classification procedure. Results of such continuum can be used as base for further traffic analysis as travel time prediction, optimal route detection etc.

Saša Petar, Morana Ivaković-Babić
2011 (Vol 23), Issue 4
The development of information and telecommunication technologies, apart from accelerating the information flows, increasing efficiency on the market and other business changes, results also in the reduction of the number of employees in companies. With the application of new information and telecommunication technologies even companies with a single employee in certain activities (publishing, counselling, tourism, etc.) can successfully compete with larger companies, which leads to an increased number of logistic service demands. A large number of small enterprises create a large number of small orders which have to be delivered in the same unit of time, thus causing increased congestion of roads, especially in urban areas. Although information transport, due to the mentioned technologies, has become to a large extent virtual, the transport of people and cargo continues to operate in a three-dimensional space (recognizing the time dimension as an important factor for calculating the business efficiency). The application of the model from the paper makes it possible to confirm the thesis of increased traffic congestion as consequence of the technological development and to emphasise the need to find a solution in the form of logistic and distribution centres for small and mid-size enterprises. The companies that offer logistic and distribution services may become centres for small and mid-size enterprises, thus offering a solution that maintains the speed and efficiency and avoids costs of congestions and delays.

Aleksandra Deluka-Tibljaš, Barbara Karleuša, Čedomir Benac
2011 (Vol 23), Issue 4
The paper deals with the selection of traffic infrastructure facility location by applying the AHP (Analytic Hierarchy Process) multi-criteria analysis methodology. The proposed methodology is applied in a case study to solve the problem of selecting a location for the garage-parking facility in the town of defined characteristics. The paper analyses the characteristics of five potential locations (alternatives), the selection of criteria and measures for assessing the alternatives and presents the input data preparation, the application of the selected method and the analysis results. All the relevant criteria for the analyses were included: the traffic, the economic criteria and those which nowadays are of great significance: the influence of the facility on the environment and the social criteria which is in accordance with the sustainable development principles. The goal of the paper is to present the procedure of the AHP method application on the complex issue of traffic planning and to confirm the adequacy of the chosen method on the traffic facility strategic planning.

Vuk Bogdanović, Ivan Dadić, Zoran Papić, Nenad Ruškić
2011 (Vol 23), Issue 4
A minor movement performed at unsignalized intersections is one of the most complex and most difficult actions in traffic. Drivers performing a minor movement make decisions based on the estimation of movement parameters of vehicles in the major street. A driver’s estimation depends on subjective estimation of the distance between vehicles in the major street and the gap which exists between them, that is, the time gap in the conflicting flow which is suitable for accomplishing a minor movement. The possibilities of estimation are sometimes limited due to complex traffic conditions, as well as the limited driver’s view. When, during doing a minor movement, a traffic accident happens, in most cases the cause of the accident is the failure to give right-of-way. But, in case when a vehicle from the major street moves at a speed above the limited one, based on the existing analytical procedures, it is impossible to determine the extent of their responsibility. This paper shows the procedure for safe distance determination, necessary for accomplishing a minor movement, as well as the procedure of establishing the driver’s omission, depending on the movement regime and traffic conditions at unsignalized intersections.

Sanja Grubeša, Hrvoje Domitrović, Kristijan Jambrošić
2011 (Vol 23), Issue 3
The efficiency of noise barriers largely depends on their geometry. In this paper, the performance of noise barriers was simulated using the numerical Boundary Element Method (BEM). Traffic noise was particularly considered with its standardized noise spectrum adapted to human hearing. The cross-section of the barriers was varied with the goal of finding the optimum shape in comparison to classical rectangular barriers. The barrier performance was calculated at different receiver points for a fixed barrier height and source position. The magnitude of the insertion loss parameter was used to evaluate the performance change, both in one-third octave bands and as the broadband mean insertion loss value. The proposed barriers of varying cross-section were also compared with a typical T-shape barrier of the same height.

Tomaž Maher, Irena Strnad, Marijan Žura
2011 (Vol 23), Issue 3
This paper presents the estimation of nine types of utility function parameters for the application in EVA mode choice model for the city of Ljubljana, Slovenia. Four different modes (private car, public transport, bike and walking) and five purposes (work, education, shopping, leisure and other) were taken into consideration. This paper presents first the design of the Stated Preference survey, then a brief review of the EVA model, different types of utility functions and the estimation method. The final log-likelihood enables comparison of different types of utility functions. The results show that absolute differences in final log-likelihood among most types of utility functions are not high despite the different shapes, which implies that different functions may best describe different variables.

Yong-Gang Wang, Gang Wei, Xu Zhu, Yu-Long Pei
2011 (Vol 23), Issue 3
Although much is known about the operation of signalized intersections, little or no empirical research has been conducted regarding bicycle capacity at these locations and the correspondent contributory factors. The purpose of this study is to accurately quantify the capacity of bikeway at signalized intersection through a fluid dispersion approach, and ultimately the lane group capacity. Using this total dispersion of bicycle flow, a relationship is also described between bicycle volume per hour and per unit width, signal parameters (length of signal cycle and green time), bicycle flow (arrival rate, density, moving velocity) and geometric intersection distance. Through the videotaping of four intersections that have significant bicycle traffic around Xiaozhai in Xi’an, China, it is ascertained that bicycle capacity varies linearly (but limited by an asymptote domain) associated with the adjustment of these parameters. The analytical results indicate that the impact saturation flow of lane groups containing right-turning vehicles and pedestrian flow at signalized intersections on bicycles is being underestimated. If this is the case, then capacity is being overestimated through the HCM 2000 capacity model and JJ37-90 approach and intersections are not being adequately designed, due to the neglect of conflict nature of mixed traffic arrivals in competing for space.

Tomislav Josip Mlinarić, Klemen Ponikvar
2011 (Vol 23), Issue 3
Energy saving is necessary in accordance with the principles of sustainable development. Energy consumption is increasing, and the production capacities are limited. The three main railway segments such as: railway infrastructure, traffic management and dynamic train movement have an important impact on energy consumption for train haulage. The aim of the research presented in this paper is to determine energy consumption efficiency for train haulage, by choosing optimal construction parameters of railway lines, modern design of railway stations, optimal traffic management and energy efficient dynamic train movement. The paper gives a concrete presentation of energy consumption in all three segments of railway traffic and proposals for rationalization of energy consumption. The infrastructure managers and rail carriers should cooperate in the process of efficiency consumption of energy for train haulage. Saving of energy is a never-ending process.

Iztok Ostan, Borut Poljšak, Eva Podovšovnik Axelsson
2011 (Vol 23), Issue 3
A survey was performed in 2008 on a representative stratified sample of 245 railroad employees in Slovenia (168 blue-collar and 77 white-collar workers) with the aim of exploring different dimensions of workers’ lifestyle health. For this purpose a special questionnaire was developed. The intensity of perceived job stress was measured with one general index based on a 4-point ordinal scale. There were 54.3% of employees who perceived their work as stressful or very stressful. No significant differences between blue- and white-collar workers were found. Twenty-six dimensions of lifestyle were measured. There were 66.9% of interviewed employees who were found to be overweight or obese (BMI 25 or higher). Differences in lifestyle between blue- and white-collar workers were not significant at the level of 0.05, except for some dimensions: blue-collar workers spend more time in the open air and sunlight and consume lunch as the main meal more regularly. In general, lifestyle was not confirmed as statistically significant (at 0.05 level) moderator of perceived job stress, explaining just 11% of variance. However, there are some dimensions that are significantly (P<0.05) associated with occupational stress: employees that have regular bowel movements, sleep well and evaluate that they do not eat too much perceive their work as less stressful.

Marija Molan, Gregor Molan
2011 (Vol 23), Issue 3
The Butterfly Flower Shower (BFS) Human Behaviour Model describes human behaviour in each demanding, possible accidental situation. The BFS human behaviour model is presented for a traffic situation. The key elements (perception, cognition, reaction) of the human behaviour are identified. Also possible limitations and errors in all elements of human behaviour are presented. The model is presented as the butterfly on the flower under the shower of interventions. The flower is environment describing traffic infrastructure composed of the environment, technology and organization. The body of the butterfly is human cognition with personality and motivation. The left wing of the butterfly is the driver’s perception. The right wing of the butterfly is the driver’s reaction. The butterfly presents the driver, the flower presents the road – the traffic infrastructure and the shower presents the shower of humanization interventions into the traffic infrastructure and into the driver. The drops from the shower are related to identified limitations in the traffic infrastructure and to the driver. They are focused on the improvements of perception, cognition and reaction abilities of the driver also with investments into the traffic infrastructure.

Rifat Akbiyikli, Seyyit Umit Dikmen, David Eaton
2011 (Vol 23), Issue 3
The long-term sustainable provision of new and high quality maintained road stock is vitally important, especially in times of economic constraint such as Europe is currently experiencing. The Private Finance Initiative (PFI) is one method of financing such large-scale, capital intensive projects. An important aspect of this form of financing projects is that the risks are borne not only by the sponsors but are shared by different types of investors such as equity holders, debt providers, and quasi-equity investors. Consequently, a comprehensive and heuristic risk management process is essential for the success of the project. The proposition made within this paper is that the PFI mechanism provides a Value-for-Money and effective mechanism to achieve this. The structure of this PFI finance and investment on a particular road project therefore enables all project stakeholders to take a long-term perspective. This long-term perspective is reflected in the mechanism of a case study of UK – Class A trunk roads which are examined in detail. This paper presents a novel solution to a modern dilemma.

Svetlana Čičević, Vladan Tubić, Milkica Nešić, Marjana Čubranić-Dobrodolac
2011 (Vol 23), Issue 3
Young drivers are over-represented in crash and fatality statistics. One way of dealing with this problem is to achieve primary prevention through driver education and training. Factors of traffic accidents related to gender, age, driving experience, and self-assessments of safety and their relationship to perceptual learning styles (LS) preferences have been analyzed in this study. The results show that auditory is the most prominent LS. Drivers in general, as well as drivers without traffic accidents favour visual and tactile LS. Both inexperienced and highly experienced drivers show relatively high preference of kinaesthetic style. Yet, taking into account driving experience we could see that the role of kinaesthetic LS is reduced, since individual LS has become more important. Based on the results of this study it can be concluded that a multivariate and multistage approach to driver education, taking into account differences in LS preferences, would be highly beneficial for traffic safety.

Katica Miloš, Ivica Jurić, Pero Škorput
2011 (Vol 23), Issue 2
The implementation of the achievements in material science both through history as well as today, is directly indicated in the improvement of the efficiency of transport means which then results in the improvement of the technology of traffic and transport. Today’s requirements in the area of engineering materials intended for the construction of transport means impose reduction of mass as one of the fundamental criterion. Consideration of the technical and technological societies have been oriented towards light materials and the possibilities of their modification in order to substitute the past traditional heavy monoliths such as iron, steel, copper, etc. The potential has been recognised in the aluminium-based materials. Aluminium and its versions have been already widely used in automotive industry; however, their utility spectrum still avoids the tribologically sensitive purposes. This paper is focused on the possibility of producing such a material. Ceramic particles Al2O3 have been integrated into soft aluminium, various particle sizes and share, by powder metallurgy techniques. The mechanical properties of materials have been studied in dependence on the share, size of particles, type of Al/Al2O3, as well as the graphite addition. Al/Al2O3 composites have been produced without any problems and have shown satisfactory mechanical properties. KEYWORDS: reduction of transport means mass, aluminium-based composites, Al/Al2O3 composites

Zmago Skobir, Tone Magister
2011 (Vol 23), Issue 2
The subject of investigation are unmanned aircraft lighter than 150kg under control by national aviation authorities and therefore prudently requiring harmonized individual state regulations. Originated from a general premise that the unmanned aircraft regulations should evolve from the existing standards for manned aircraft of equivalent class or category, the light fixed wing unmanned aircraft equivalence to the manned aircraft is defined in the form of sets of equivalency and non-equivalency based on the established administrative type of methodology of impact kinetic energy comparison. The basic flight characteristics of the existing operational light fixed wing unmanned aircraft are analyzed assuring proper input for determination of the more realistic unmanned aircraft impact kinetic energy in controlled and uncontrolled flight into terrain crash scenarios used for the evaluation of established methodology adequacy for equivalence determination. It is shown in the paper that determination of the unmanned aircraft equivalency to the manned aircraft should not be based on the unmanned aircraft maximum take-off mass nor their airspeed range alone. KEYWORDS: light unmanned aircraft, impact kinetic energy, hazard potential, classification

Bojan Beškovnik, Elen Twrdy
2011 (Vol 23), Issue 2
This article presents a strategic view of industry’s expectations from the lean supply chains concept in relation to the container shipping industry. The global market is putting the shipping industry under strong pressure as new trends in logistics seek new opportunities to cut unnecessary costs and players in the supply chain management and in the intermodal transport. For this reason we performed a research on how the intermodal transport can secure efficient transport operations. The emphasis is mainly on setting up the agile port and intermodal transport model, in which all necessary subjects should be involved in a unique supply chain. Thus we analyzed port operators, shipping lines and inland transport operators and the way they eliminate waste processes in their everyday operation procedure. Considering all important dynamic facts in the container and shipping industry and our analyses of the intermodal service through the port of Koper we propose the agile port and inland operations model suitable to improve intermodal service and to secure lean supply chains for containerized cargo. Consequently, we came to the conclusion that some traditional subjects in the traditional supply chain are not needed; while others, like customs authorities and inspection companies should be involved adequately to secure efficient organization of agile services in the ports, on the borders between different countries and at final destinations. KEY WORDS: lean supply chains, agile intermodal operations, shipping lines, port operators, inland transport operators

Dejan Paliska, Milan Batista, Roman Starin, Daša Fabjan
2011 (Vol 23), Issue 2
Court expertise dealing with the reconstruction of road traffic accidents often have to take into account the possibility that an accident could have been a set-up. Such suspicions can be eliminated only by considering all the evidence material from the accident scene. In case of photographic material experts come across the missing material, bad lighting, lack of contrast, different angle perspectives, blurring, omitting important details, etc. Therefore, different methods in forensics image processing have been developed. Most of these methods are primarily used in the processing of different types of photographic material, but some can be applied in the field of road accidents analyses. This paper shows the implementation of digital image processing methods used for processing of remotely sensed imagery. Even though the photographic evidence is incomplete, it is possible to determine the position and dispersion of different materials. This gives the experts additional information that can help in understanding with relatively high probability if the collision between vehicles occured at all and if it did, where. The paper consists of the presentation and description of methods used for digital image processing in a real case study while reconstructing the road accident. KEY WORDS: road traffic accidents, forensics, induced traffic accidents, image classification, digital image processing

Gordan Badurina, Zvonimir Majić, Stanislav Pavlin
2011 (Vol 23), Issue 2
Pharmaceutical industry like aviation is one of the most regulated industries today. Shipping pharmaceutical products under defined time and temperature conditions is a challenge deriving from regulatory and product quality aspects. Good distribution practice should be valid throughout the distribution chain but regulatory issues are still short of strength in practice. Transportation should be considered as extended warehousing, still compliances are business rather than regulatory driven. The paper demonstrates deviations between shipping requirements and realistic capabilities of today’s commercial aviation in terms of maintenance of the controlled room temperature. Examples show cases of temperature deviations during transport realization. Suggestions are made on future research in the field of air transportation. KEY WORDS: good distribution practice, regulatory issues, controlled room

Francisco Campuzano Bolarín, Antonio Guillamón Frutos, Andrej Lisec
2011 (Vol 23), Issue 2
Price fluctuation is a practice commonly used by companies to stimulate demand and a main cause of the Bullwhip effect. Assuming a staggered step demand pattern that responds elastically to retailer’s price fluctuation, and by using a supply chain management dynamic model, we will analyse the impact of these fluctuations on the variability of the orders placed along a traditional multilevel supply chain. Subsequently, the results obtained will serve to propose a forecasting model enabling to calculate the potential variability of orders placed by each echelon on the basis of the price pattern used. Finally, under the hypothesis of an environment of collaboration between the different members of the chain, we propose a predictive model that makes it possible to quantify the distortion of the orders generated by each level. KEYWORDS: Bullwhip effect, systems dynamics, price fluctuation, supply chain management

Karel Greiner
2011 (Vol 23), Issue 2
The paper describes the facilities of a new application serving for entering railway undertakings requirements related to train tracks in the conditions of the Czech Republic. The application is a part of a new information system of the train timetables configuration. The train editor represents a distributed application consisting of a database server, application server and a client program. It contains most of the data of trains available in the programming schedule. In addition to features for working with trains, it provides a variety of analytical tools and printing of tools for railway workers and passengers. In order to coordinate compiling of the timetable by the infrastructure manager, a train-making procedure was designed based on the stages of the train. KEY WORDS: timetable, train, information system, distributed application

Marko Pršić, Dalibor Carević, Davor Brčić
2011 (Vol 23), Issue 2
The article provides a definition of inland waterway parameters with the emphasis on the international waterway classes IV, Va and Vb relevant to the Sava River. The parameters have been defined through the comparative analysis based on international classification of inland waterways, the available theoretical assumptions, and available and published physical model researches. The channel parameter problems have not been considered herein. The philosophy of the applicable UN/ECE classification of 1992 consists in defining the relevant waterway structures and navigable water levels only. The waterway parameters are then determined in compliance therewith for each individual waterway based on the navigable channel morphology, through the morphological, technical and economic analysis. Through such an iterative procedure, a detailed standardization of the Sava River waterway parameters was created for the international classes IV, Va and Vb, serving as basis for the current analysis of the Sava River navigability for the purpose of gaining informative concept of the scope of water works to be executed and the financial dimension of requested works for short-term and long-term periods. KEY WORDS: inland waterway, the Sava River, waterway class, standardization, river bed morphology

Pavao Komadina, Vinko Tomas, Marko Valčić
2011 (Vol 23), Issue 1
This paper presents a combinatorial model for the identification and simulation of a certain number of parameters of marine steam turbine plant for LNG tankers based on the classification and approximation neural networks. The model consists of two basic parts. In the first part, parameters are classified in adequate clusters by means of self-organizing neural network, while the combinatorial identification of clusters interrelationship is carried out in the second part by means of static feed-forward neural networks. In the following part, the successfulness of the achieved results is analyzed by generating an adequate rank-list of all identification-simulation models. This approach gives a clear insight into certain cluster interdependences which can significantly contribute in following applications which are based on the estimation and prediction of the lost sensor information not depending on the cause of their loss. Although all of the above is distinctly expressed in marine propulsion control systems, it should be pointed out that in this way significantly increased reliability and redundancy of the sensor information directly reflect on considerable increase in technical security of the whole ship as a floating object. KEY WORDS: marine steam turbines, marine control systems, neural networks, identification, clusterization

Saša Petar, Ivona Bajor, Siniša Radulović
2011 (Vol 23), Issue 1
The capital and technology transfer into a certain region leads also to increased demands for logistic services. The transition to the logistic delivery organisation is very important under the conditions of accelerated technological development, in particular in the field of telecommunications and informatics, which enabled the advent of successful companies having a single employee. Owing to the mentioned technologies these companies get networked with similar companies, thus being able to solve all their needs by outsourcing the services or products of other networked companies. Higher speed and greater flexibility of operation of such companies has brought the following challenge: larger number of small companies has created a larger number of small orders that have to be delivered within the same unit of time. The logistics and distribution centres can represent a solution which maintains the speed and efficiency, and avoids costs of congestions and delays. KEY WORDS: capital transfer, technology transfer, logistics and distribution centres, optimisation

Ratko Zelenika, Tomaž Lotrič, Ervin Bužan
2011 (Vol 23), Issue 1
Multimodal transportation means transporting goods from a pickup point, where the operator receives the goods, all the way to the delivery location, using at least two different means of transportation, covered under the same multimodal transport contract and by only one document, regardless of the number or type of transportation vehicles used. The key factor to the optimal operation of multimodal transportation is the multimodal transport operator. It is up to this individual to compensate for various unpredictable circumstances, the complexity of the business processes, nature’s whims and carelessness. He must also organize and execute multimodal transport in all stages. Due to the above mentioned dangers and the fact that the area of liability insurance for multimodal transport operators is still being neglected, this article raises some valid points in favour of a proposal that would cover all of the transportation means as well as all the accompanying activities with a single insurance policy. The model includes 17 elements of liability insurance for a multimodal transport operator and all values which quantify the insurance elements in 2009 as well as the projected values for 2015, when progress is expected in the areas pertaining to the implementation of economical processes concerning transit development, as well as values for 2025, representing a period of innovation, reconstruction, optimization and modernization. With this supposed model for liability insurance of a multimodal transport operator, the foundation is laid for a liability insurance which would be used by a multimodal transport operator. KEYWORDS: transport insurance, multimodal transport, multimodal transport operator, multimodal transport operator liability systems

Rita Markovits-Somogyi
2011 (Vol 23), Issue 1
Efficiency analysis of transport systems can be carried out using numerous different techniques. Experts generally distinguish them as parametric and non-parametric methods, or else as methods using a production function, an index or not using anything of this kind. Based on the literature and on own research the present paper sets up a clear systematization of these techniques giving a brief summary of their essence while also providing examples of their application in the transport sector. Having elucidated each method, the author also outlines the correlation and the reliability of the techniques and presents a novel view which stresses the importance of links between the different techniques. KEY WORDS: efficiency measurement, transport, TFP, MPI, SFA, DEA, OCRA

Toni Bielić, Robert Mohović, Renato Ivče
2011 (Vol 23), Issue 1
This article investigates the possibility of optimizing the organization of a ship as a highly complex technical system. In this sense, the existing relationship between technology and the human as a user is considered. Using the socio-technical approach the aim is to identify the weaknesses in the existing technological and organizational ship’s system. Based on research conducted on the navigation simulator, socio-technical components that affect the safety of navigation have been observed. By subsequent comparative analyses of the implementation of technical solutions in accordance with the human requirements certain solutions are proposed and conclusions made. KEY WORDS: socio-technical model, ship organization, safety, effectiveness, technology indulgence, control systems, automation

Alen Jugović, Svjetlana Hess, Tanja Poletan Jugović
2011 (Vol 23), Issue 1
Successful management of any sea port depends primarily on the harmonisation of transport supply and demand, whereas their incompatibility leads to a number of problems. The port, i.e. its management, through its operation and part of port policy may affect the planning of the construction or modernization of its port facilities. In doing so, the specified planning requires forecasting and quantification of the needs for infrastructural services of specified port, i.e. assessment of traffic demand. Accordingly, the basic problem of research in this paper is forecasting of traffic demand for the port services by applying the appropriate forecasting methods. In order to find ways of solving concrete problems in the port operations the methods for traffic demand forecasting are set by applying the methodology and the presentation of the application of economic forecasting methods. The selected methods of demand forecasting for port services in demand are illustrated and tested on the example of the Croatian largest cargo port, the Port of Rijeka. KEY WORDS: planning, forecasting, traffic demand, commodity flows, port capacity

Ljudevit Krpan
2011 (Vol 23), Issue 1
The new generation of physical planning documents requires adaptation to new economic and other development plans as well as to new parameters of the modern society development. Therefore, it is necessary to insure high-quality planning foundations which will serve as the basis to determine the basic guidelines of physical plans. This refers especially to the need for integral consideration of the development of traffic and the traffic infrastructure in compliance with the space requirements and possibilities. In order to evaluate the objective parameters of physical and traffic planning, the traffic studies carried out as required for the production of the physical planning documentation of the new generation have been analyzed. The goal of research was to determine the credibility of infrastructure development plans predefined by the documents of physical planning from the region of the Primorje-Gorski Kotar County. The paper presents the results of initial research carried out for the requirements of producing the Physical and Traffic Integral Study of the Primorje-Gorski Kotar County and the city of Rijeka. According to overall distribution of responses it may be concluded that there is great gap in knowing the procedures of traffic and spatial planning among specialized traffic agencies and the rest of the respondents. KEY WORDS: physical and traffic planning, urbanism, physical planning documentation, space-traffic interrelation

Ali Tavakoli Kashani, Afshin Shariat-Mohaymany, Andishe Ranjbari
2011 (Vol 23), Issue 1
Seventy percent of the traffic crash fatalities of Iran happen on rural roads, and a significant proportion of the rural roads network of this country is constituted of the main two-lane, two-way roads. The purpose of this study is to identify the most important factors which affect injury severity of drivers involved in traffic crashes on these roads, so that by eliminating or controlling such factors an overall safety improvement can be accomplished. Using the Classification and Regression Tree (CART), one of the powerful data mining tools, the crash data pertaining to the last three years (2006-2008) were analyzed. The variable selection procedure was carried out on the basis of Variable Importance Measure (VIM) which is one of the CART method outputs. The results revealed that not using the seat belt, improper overtaking and speeding are the most important factors associated with injury severity. KEYWORDS: injury severity; traffic safety; data mining; Classification and Regression Trees (CART); Variable Importance Measure (VIM)

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University of Zagreb, Faculty of Transport and Traffic Sciences
Online ISSN
1848-4069
Print ISSN
0353-532
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