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Hedvika Kovandová, Robert Válka
2014 (Vol 26), Issue 6
The paper deals with safety of transport from the point of view of an important social problem, which are accidents at railroad (including tramway) and road level crossings, which means compatibility of rail and road vehicles crash. The scale of such accidents can be very wide. Regarding the statistics and frequency of accidents particularly at railway level crossings and tramway level crossings, a collision simulating the collision of a tram and passenger car was experimentally carried out. The experiment took place at the site of testing laboratory of Rail Vehicles Research Institute in Cerhenice. The experiment was conducted with a passenger car Škoda Superb of the first generation that was exposed to two collisions from both sides. Firstly by the impactor for tram headstock tests and secondly by the tram headstock itself. Both the impactor and the headstock were placed on the experimental vehicle for tests of passive safety of rail vehicles. Various speeds were chosen so that the passenger car could be used for two subsequent experiments without the influence on properties of skeleton´s supporting structure.

Zhizhou Wu, Li Zhao, Jian Sun
2014 (Vol 26), Issue 6

Traffic conflicts among right-turn vehicles (RTVs), non-motorized vehicles (NMVs) and pedestrians were examined for urban signalized intersections with exclusive right-turn lane. This study proposed an approach to dynamically calculate the duration of the prohibited right-turn for vehicles by using a measure called the Degree of Clustered Conflict (DCC). The process of DCC control includes: 1) quantitative calculation of DCC value in the conflict area; 2) establishing the general cost model that combines the delay and conflict indicators; and 3) applying the DCC-control time model to control RTV in real time. Based on these, the paper presented a general approach of detailed dynamic on-line signal control process of RTV. Finally, the RTV control process was programmed based on VISSIM simulation to evaluate the control effectiveness. The results showed that the general cost (weighted summation of delay and conflict) of the RTV control decreases rapidly compared with non-control, fixed control and full control (drop of 58%, 35% and 42% under small flow conditions and 70%, 59% and 17% in the large flow conditions, respectively). The method not only improved the operation efficiency, but also reduced the potential safety risks among traffic participants when vehicles turn right at intersections.

Ishtiaque Ahmed, Suleiman Abdulrahman, Mohd Rosli Hainin, Sitti Asmah Hassan
2014 (Vol 26), Issue 6

Transportation planners need to estimate the trip generations of different land use types in the travel demand forecasting process. The Trip Generation Manual of Malaysia, similar to the Trip Generation Manual of the Institute of Transportation Engineers, USA, provides the trip generation rate at “Polyclinics” as a function of the Gross Floor Area. However, the data for this rate have no line of best fit resulting in the lack of confidence in the prediction. This study considered ten locations in Malaysia and verified the significance of different parameters, i.e. Number of Doctors, Number of Staff, Gross Floor Area and Density of Similar Clinics within 0.5 kilometre radius in Johor Bahru, Malaysia. The study developed regression equations for estimating the peak hours and daily trips at polyclinics in terms of “Number of Doctors”. The developed models can be used in estimating the number of trips generated by the polyclinics in Johor Bahru, Malaysia.

Qingyang Xu, Ning Wang
2014 (Vol 26), Issue 6
Recently, ship collision avoidance has become essential due to the emergence of special vessels like chemical tankers and VLCCs (very large crude carriers), etc. The information needed for safe navigation is obtained by combining electrical equipment with real-time visual information. However, misjudgements and human errors are the major cause of ship collisions according to research data. The decision support system of Collision avoidance is an advantageous facility to make up for this. Collision risk evaluation is one of the most important problems in collision avoidance decision supporting system. A review is presented of different approaches to evaluate the collision risk in maritime transportation. In such a context, the basic concepts and definitions of collision risk and their evaluation are described. The review focuses on three categories of numerical models of collision risk calculation: methods based on traffic flow theory, ship domain and methods based on dCPA and tCPA.

Victor Cantillo, Miguel Jaller, Jose Holguín-Veras
2014 (Vol 26), Issue 6
Freight transport modelling at interregional scale is relevant for planning issues. However, freight modelling processes are complex because it is not easy to define the relevant variables in the analysis, and to obtain the required information on freight movements through the network. These facts raise the need to adapt the modelling framework to each context.
This paper proposes a strategic national freight transport modelling framework developed as a variant of the traditional four-step modelling process with additional steps to estimate traffic flows from freight flows and to consider empty trips. The country of Colombia is used as the case study to implement and calibrate the proposed model. The data, data sources, and modelling methodologies used for each step are explained. In addition, data limitations and measures taken to complement the available data are discussed. From the implementation, the authors identify a set of advantages derived from the modelling approaches considered and suggestions for improvement.

Elen Twrdy, Andrej Androjna, Marko Pavliha
2014 (Vol 26), Issue 6
In the modern world, the sea is one of the most important resources for the economy and welfare of the country that has access to it and so is the sense of security. Meeting today’s security challenges requires a wide spectrum of civil and military instruments. It calls for regular coordination, consultation and interaction among all actors involved, and it requires a national multifunctional Structure.
The paper presents the search for new systematic forms to ensure adequate maritime security and safety at sea. Based on the research on successfully organized similar foreign institutions in relation to the national security institutions in the maritime domain the Coast Guard model of the Republic of Slovenia has been designed. The model could significantly improve the level of efficiency and consistency of national authorities in the area of control, security and safety of the territorial sea and rationalize expenditures. Implementing the proposed model and placing it in the national security and defence system, is a challenge and also a need.

Diana Božić, Ratko Stanković, Kristijan Rogić
2014 (Vol 26), Issue 6

Raising the service level and developing new logistic services require better understanding of logistic processes and possibilities of optimization. Different methodologies have been used for that purpose, while the application of Business Process Management (BPM) methodology is outlined in this paper. Identifying parts of logistic processes that could be optimized is facilitated by applying BPM methodology. It also enables more accurate quantification of impacts of the changes introduced in a particular process or activity on the processes as a whole and to other interacting processes. The application of BPM methodology is demonstrated in the case study, where a solution for logistic processes optimization is suggested and the prospective outcomes are simulated. The results of the logistic process comparative analysis have indicated a synergic effect of different improvements in sub-process on the effectiveness of the process as a whole, both on the operative and managerial level. The respective changes in workload distribution among interacting logistic processes have been quantified according to the same methodology.

Zhigang Du, Hongliang Wan, Chaozhong Wu, Xiaodong Pan
2014 (Vol 26), Issue 5

Utilizing the EMR-8B eye-tracker system, the pupil changes of eight drivers were monitored when they drove through 26 typical highway tunnels. Based on the test results, the driver’s pupil areas and pupil illuminance were found to be in a power function relationship at tunnel entrances. Furthermore, a quantitative relationship between the pupil area and its critical velocity was established, and the ratio of pupil area’s velocity in relation to its critical velocity was used to evaluate the lighting transitions and to establish the ideal curve of pupil illuminance at tunnel entrances. The results demonstrated that the relationship between the pupil illuminance of the tunnel entrance and the driver’s pupil areas conforms to the Stevens law found in experimental psychology; severe pupil illuminance transition within the range of 10 metres of the existing highway tunnel entrances, which results in great visual load, is in urgent need of improvement.

Hamid Behbahani, Navid Nadimi, Hooman Alenoori, Mina Sayadi
2014 (Vol 26), Issue 5

Collision avoidance system (CAS), with the help of surrogate safety measures is a beneficial tool for reducing driver errors and preventing rear-end collisions. One of the most well-known surrogate safety measures to detect rear-end conflicts is Time-to-collision (TTC). TTC refers to the time remaining before the rear-end accident if the course and the speed of vehicles are maintained constant. Different surrogate measures have been derived from TTC; however, the most important are Time Exposed Time-to-collision (TET) and Time Integrated Time-to-collision (TIT). In this paper a new surrogate safety measure based on TTC notion has been developed. This new indicator merges TET and TIT into one measure and gives a score between 0 and 100%, as the probability of collision. Applying this indicator in CAS as a safety measure will be more useful than TET&TIT, to reduce driver errors and rear-end collisions.

Zhenyu Mei, Dianhai Wang, Jun Chen, Wei Wang
2014 (Vol 26), Issue 5

Filtering the data for bicycle travel time using Bluetooth sensors is crucial to the estimation of link travel times on a corridor. The current paper describes an adaptive filtering algorithm for estimating bicycle travel times using Bluetooth data, with consideration of low sampling rates. The data for bicycle travel time using Bluetooth sensors has two characteristics. First, the bicycle flow contains stable and unstable conditions. Second, the collected data have low sampling rates (less than 1%). To avoid erroneous inference, filters are introduced to “purify” multiple time series. The valid data are identified within a dynamically varying validity window with the use of a robust data-filtering procedure. The size of the validity window varies based on the number of preceding sampling intervals without a Bluetooth record. Applications of the proposed algorithm to the dataset from Genshan East Road and Moganshan Road in Hangzhou demonstrate its ability to track typical variations in bicycle travel time efficiently, while suppressing high frequency noise signals.

Seyed Hadi Hosseini, Behzad Moshiri, Ashkan Rahimi-Kian, Babak Nadjar Araabi
2014 (Vol 26), Issue 5
Traffic flow forecasting is useful for controlling traffic flow, traffic lights, and travel times. This study uses a multi-layer perceptron neural network and the mutual information (MI) technique to forecast traffic flow and compares the prediction results with conventional traffic flow forecasting methods. The MI method is used to calculate the interdependency of historical traffic data and future traffic flow. In numerical case studies, the proposed traffic flow forecasting method was tested against data loss, changes in weather conditions, traffic congestion, and accidents. The outcomes were highly acceptable for all cases and showed the robustness of the proposed flow forecasting method.

Željko Ivanović, Sanja Bauk
2014 (Vol 26), Issue 5
The process of urbanization of coastal tourist destinations (CTDs) is taking place at high speed and at the same time creating a lot of complex problems. The positive trend of urbanization has resulted in increased volume of freight transport which leads to burdening the traffic network, time losses and causes traffic congestion problems on the streets with increased environmental pollution due to emissions, noise and vibration. These findings brought to some research being started on the EU level, aiming to develop new logistic solutions, so these areas could be developed on a sustainable basis. With this in mind, the paper proposes a method of developing a novel model of logistics (MoL) for CTDs through several stages. The point of proposed MoL lies in achieving optimal connectivity of transportation, warehousing and physical distribution of goods, and making it a single functional model, so as to allow simultaneous optimization of logistic processes in a CTD, and to incorporate logistics in tourist offer.

Luka Novačko, Ljupko Šimunović, Davor Krasić
2014 (Vol 26), Issue 5
This paper presents a model of data assessment for the requirements of a classical four-step model of traffic demand in individual traffic in small cities. The procedure is carried out by creating an initial origin-destination trip matrix using data from the traffic count and by defining the average rate of trip generation within single households. The research applied fuzzy logic for the correction of the initial trip matrix. The paper also presents the recommendations for defining the borders of traffic zones, as well as the locations of traffic counts. A flowchart has been used to show a summarized presentation of the proposed model. In the last part of the paper the model was tested on an example of a smaller city in the Republic of Croatia.

Monika Kontelj, M.Sc., Igor Jakomin, D.Sc.
2014 (Vol 26), Issue 5

Using specific science methods and through a model, authors have determinated how investments in the railway infrastructure influence the whole railway system. We have based our research on experience and on results that have been found out in Austria, Argentina, Bolivia, Brasil, Chile and Venezuela. Based on scientific studies about the conditions of the Slovenian railway system, on Methodology for determination of the investment's measures and definition of conditions for a justified realisation and on Calculation of the expected number of freight trains, authors give results that confirm our hypothesis.

Toni Bielić, Dalibor Ivanišević, Ana Gundić
2014 (Vol 26), Issue 5

This paper analyse the participation - based model on board the ship as possibly optimal leadership model existing in the shipping industry with accent on decision - making process. In the paper authors have tried to define master’s behaviour model and management style identifying drawbacks and disadvantages of vertical, pyramidal organization with master on the top.

Paper describes efficiency of decision making within team organization and optimization of a ship’s organisation by introducing teamwork on board the ship. Three examples of the ship’s accidents are studied and evaluated through “Leader - participation” model. The model of participation based management as a model of the teamwork has been applied in studying the cause - and - effect of accidents with the critical review of the communication and managing the human resources on a ship. The results have showed that the cause of all three accidents is the autocratic behaviour of the leaders and lack of communication within teams.

Aleksandar Sušić, Davor Sumpor
2014 (Vol 26), Issue 5

Ali Sercan KESTEN, Kemal Selçuk Öğüt
2014 (Vol 26), Issue 4

This paper presents a practical approach for monitoring public transportation systems' performance by focusing on customer evaluations. Within the framework of the developed method, 22 indicators are aggregated for 6 different measures, which are time, cost, accessibility and transfer, comfort, safety – security and quality of service respectively. Passenger Oriented Performance IndeX (POPIX) has been developed and applied to the Istanbul Metro, Light Rail and Tram systems. The goal of this research is to propose a new customer oriented performance index for transportation systems, enabling a reliable and objective base for monitoring system performance by setting performance goals and identifying priorities. Meanwhile, the proposed methodology also allows for the investigation of the performance changes of a particular transportation system and for performance comparison of different systems directly from the customer point of view. The data of the index is attained by the Customer Satisfaction Survey of Istanbul Public Railways' 2005, 2006 and 2007. The POPIX methodology has been defined and the corresponding POPIX scores are calculated for the systems investigated. Furthermore, the % POPIX concept has been developed for the comparison of different systems. Lastly, the shifted POPIX concept has been proposed for more reliable comparison between different years. The framework has been implemented to the public railway systems and individual index scores are calculated for each indicator, measure and overall system. The measures of cost, accessibility and transfer and comfort have lower index scores. Metro index scores are superior in comparison to the Tram and Light Rail for all the years analyzed.

Journal Editorial Board
2014 (Vol 26), Issue 4

Ivan Bolkovac, Marko Horvat, Kristian Jambrošić, Hrvoje Domitrović
2014 (Vol 26), Issue 4
The paper discusses the issue of adding artificial warning sounds to hybrid and fully electric vehicles, in order to increase traffic safety by making these vehicles audible at low speeds. The goal of this modification is to enable the pedestrians to perceive possible danger coming from such a vehicle in time to respond accordingly. Following the results of previous research which state that the sounds of internal combustion engines are valid candidates for artificial warning sounds to be added to hybrid or fully electric vehicles, a preliminary examination of the suitability and acceptability of different engine sounds in various modes of operation has been conducted. The chosen modes of operation are running in idle, at 2000 rpm and 3000 rpm with the vehicle stopped. Both gasoline and diesel engines were investigated. To expand the range of engine sounds, the type of vehicles was not limited to personal cars. The results show significant differences in suitability of engine sounds for the stated purpose, with vehicle type being the main differentiating factor.

Ji-Young Song, Jin Ki Eom, Sung Il Kim
2014 (Vol 26), Issue 4

We analyzed the travel patterns of senior citizens in Seoul using Automatic Fare Collection (AFC) data. We focused specifically on mode choices and transfer patterns. Results showed that 99% of trips made by senior citizens (individuals over 65 years old), who were given free subway transit passes, consisted of single-mode trips. Average travel time was 31 minutes, and subway travel times were longer than bus travel times. Individuals made fewer transfers, took longer metro trips, and paid smaller fares when using their free subway transit cards. They were more negatively sensitive to bus travel time than metro travel time. Encouraging older adult travelers to use transfers that increase costs to a modest extent might help improve travel quality among a group of individuals who find it difficult to enter the metro system or who are uncomfortable making inter-metro transfers. Additionally, as older adults have more time, yet are economically disadvantaged and take more leisure trips, travel improvements could include adopting a time-flexible fare discount. We discuss these improvements in terms of the individual and social benefits afforded to transit passengers in South Korea.

Deng Pan, Yingping Zheng
2014 (Vol 26), Issue 4

Both safety and efficiency should be considered in high-speed train following control. The real-time calculation of dynamic safety following distance is used by the following train to understand the quality of its own following behavior. A new velocity difference control law can help the following train to adjust its own behavior from a safe and efficient steady-following state to another one if the actual following distance is greater than the safe following distance. Meanwhile, the stopping control law would work for collision avoidance when the actual following distance is less than the safe following distance. The simulation shows that the dynamic control of actual inter-train distance can be well accomplished by the behavioral adjustment of the following train, and verifies the effectiveness and feasibility of our presented methods for train following control.

Zvonimir Lušić, Serđo Kos, Stipe Galić
2014 (Vol 26), Issue 4
Today's methods of plotting courses and selecting sailing routes and turn points in maritime navigation are still largely based on subjective assessment of the master or the officer in charge. This results in a great variety of course distribution and, accordingly, in various ship movements. Modern electronic aids, in particular ECDIS (Electronic Chart Display and Information System) can significantly facilitate maritime voyage planning, course plotting, selection of turning points, etc. In addition to displaying electronic charts, the specific feature of these systems is that they facilitate route planning, supervision of ship movements, data recording, database search, alarm setting, etc. However, these systems do not yet provide automatic selection of courses on user's request in a standardised form. Therefore, in most cases, the routes and turn points are selected empirically or because they have been previously defined and used. This paper shows the drawbacks of the existing methods of selecting routes and plotting courses in maritime navigation and gives recommendations how to improve them.

Rafał Burdzik, Maria Cieśla, Aleksander Sładkowski
2014 (Vol 26), Issue 4

The paper presents assessment of the impact of the processes handling efficiency on the transport process based on research done in the real object, using same technologies and material handling equipment. The aim of the paper was to confirm importance of loading and unloading processes of palletized cargo as an initial and final link of multimodal transport by developing methods’ proposal for monitoring and assessing the effectiveness of cargo operations as well as development of measures and comparison estimators. The analysis of the manipulation operations’ duration throughout the transport process is based on the percentile rates of manipulation and carriage in total transport process duration and the percentage of manipulating time in the duration of the carriage. These indicators and examined loading and unloading times, are the basis for the development of scheduling algorithms for optimizing transport processes on the scale of the whole transport chain. This data is also a helpful input to support strategic decisions on the allocation of financial resources for the development of infrastructure and terminal equipment, warehouses and other facilities.

Carlos A Silva, Carlos Guedes Soares
2014 (Vol 26), Issue 4
The potential growth found inthe short sea shipping sector motivated the development of a methodology usedas a decision support tool in which both the parameters regarding the demand ofmarkets and the characteristics of the fleet may be tested for its evaluation.It is also possible to determine the fleet deployment, establishing its routesand scales in the ports for a particular scenario. The considered methodologymay be divided in two parts, being the first one related with the generation ofall feasible routes, alongside all the parameters specific to each route foreach vessel class. The second part is the introduction of a linear programmingmodel that maximizes the shipping operation’s total profit, according a givenset of restrictions. The models were structured according to three main criteria:the evaluation of the fleet for each vessel’s class; the optimal route for eachvessel and the frequency in each port. To provide the methodology’s validation,the developed models shall be submitted to a fictitious operational scenario,considering three different situations: the fleet’s normal operation; aparametric variation of required demand for the same fleet composition; anevaluation of several fleet compositions for the same demand level.

Marino Lupi, Alessandro Farina, Antonio Pratelli, Alessandra Gazzarri
2014 (Vol 26), Issue 4
In this paper, the existing rules commonly used for port traffic comparison are described. These rules provide weighting factors for each freight category in order to make them comparable and exploitable for port ranking. These rules are based on the value added concept related to port activities. Two new rules are proposed. The first is again based on the value added concept. The second rule is based on the assumption that ports not only create labour directly, through activities related to port operations, but they also play the role of “gates” for the existing economic activities of a region or a country, as a consistent quota of the overall international trade takes place by sea. This rule is based on the relationship among the trend of traffic volume of each freight category and the trend of the national GDP. The rules existing in the literature and the proposed new rules have been applied in ranking Italian ports; the results are discussed. The sensitivity of the ranking of Italian ports, to the different weighting rules, has been analysed.

2014 (Vol 26), Issue 3

Based on Turkish traffic survey data (n=5,520), driver accident rates per million kilometre-driver were compared according to the daily driven distances (DDD) for each age group as very old (65+, n=39), old (56-65, n=183), above middle-aged (36-55, n=1,875), middle-aged (26-35, n=2,204), and young (25-, n=1,219). When the accidents-per-km comparison was made in groups matched for daily exposure, there was no evidence of higher risk with increasing age. In all age groups, risk per km decreased with increasing daily driving distance. With this study the accident involvement prediction models have been obtained related to the daily driven distance with and without considering age. These models have been applied to some earlier studies. The results are quite satisfactory. The set of data of this study and the analysis controlling the daily (yearly) driving distance might make the “age” effect disappear.

Xuecai Xu, Željko Šarić, Ahmad Kouhpanejade
2014 (Vol 26), Issue 3

Classification and Regression Tree (CART), one of the most widely applied data mining techniques, is based on the classification and regression model produced by binary tree structure. Based on CART method, this paper establishes the relationship between freeway incident frequency and roadway characteristics, traffic variables and environmental factors. The results of CART method indicate that the impact of influencing factors (weather, weekday/weekend, traffic flow and roadway characteristics) of incident frequency is not consistent for different incident types during different time periods. By comparing with Negative Binomial Regression model, CART method is demonstrated to be a good alternative method for analyzing incident frequency. Then the discussion about the relationship between incident frequency and influencing factors is provided, and the future research orientation is pointed out.

Atilla Senih MAYDA, Muammer YILMAZ, Filiz BOLU, Mustafa USLU, Nuray YEŞİLDAL
2014 (Vol 26), Issue 3
The aim of the study is to estimate hospitalization and mortality rates in patients admitted to the University Hospital due to traffic accidents, and to determine the mean cost of the applicants in the hospital due to traffic accident. In this retrospective study data were obtained from the records of a university research and practice hospital. There were 802 patients admitted to emergency and other outpatient clinics of the University Hospital because of traffic accidents throughout the year 2012. Out of these patients, 166 (20.7%) were hospitalized, and the annual mortality rate was 0.87%. The total cost was 322,545.2 euro and 402.2 euro per patient. Road traffic accident detection reports covered only the numbers of fatal injuries and injuries that happened at the scene of accidents. Determination of the number of the dead and wounded with overall mortality rate would be supposed to reveal the magnitude of public health problem caused by traffic accidents.

Danwen Bao, Tangyi Guo, Hongshan Xia
2014 (Vol 26), Issue 3
In much of studies on spatial mismatch between residential and employer locations, job accessibility has been measured. However, the apparent disadvantages of the traditional measurement methods on the studies of Chinese cities have been noted.  This paper proposed an optimized method for job accessibility measurement by introducing the weigh coefficient of job opportunity, which quantifies the degree of uneven distribution of job opportunity in the Chinese cities. Take Nanjing city for example, this new method was used to measure the spatial distribution of job opportunity, investigate the spatial patterns and analyze the influences of job accessibility on commuting behavior. The results show that the distribution of job accessibility in Nanjing exhibits the different spatial patterns and mechanisms compared with US cases.

Katarzyna KOCUR-BERA
2014 (Vol 26), Issue 3

This paper discusses the issue of statistical analysis of traffic flow in different regions of Poland. Such analysis allows us to identify “valuable (sensitive) areas” whose damage or blockage may provoke considerable disturbances or even a stoppage of traffic flow in the examined road network. The results of the studies indicate that the road network in Poland has the properties of a scale-free network. The distribution of the examined variables does not have a normal character, whereas the relationship between the number of nodes and the number of connections is a power-law feature.


Gholamreza Ilati, Abdorreza Sheikholeslami, Erfan Hassannayebi
2014 (Vol 26), Issue 3

Todays, due to the rapid increase in shipping volumes, the container terminals are faced with the challenge to cope with these increasing demands. To handle this challenge, it is crucial to use flexible and efficient optimization approach in order to decrease operating cost. In this paper, a simulation-based optimization approach is proposed to construct a near-optimal berth allocation plan integrated with a plan for tug assignment and for resolution of the quay crane re-allocation problem. The research challenges involve dealing with the uncertainty in arrival times of vessels as well as tidal variations. The effectiveness of the proposed evolutionary algorithm is tested on RAJAEE Port as a real case. According to the simulation result, it can be concluded that the objective function value is affected significantly by the arrival disruptions. The result also demonstrates the effectiveness of the proposed simulation-based optimization approach.

Lena Winslott Hiselius
2014 (Vol 26), Issue 3

This paper brings to the fore the importance of a holistic approach to attaining a general pro-environmental behavioural change in order to reduce carbon emissions and the need to strive for a spillover of pro-environmental behaviour from one area to another. An adjusted version of the MaxSEM model is developed to capture differences in stages of behavioural change regarding environmental load on entering a Mobility Management campaign and one year after. The analytical tool is applied on two test samples in order to illustrate the tool and possible difficulties and methodological challenges. The test samples consist of participants in Mobility Management campaigns with personal incentives in two cities in Sweden. The application of the tool indicates e.g. that the timing of the survey is important and that there is need to upscale the MM-campaigns, in order to further discuss and analyse the effects of voluntary mobility measures in other domains.

Mario Šafran
2014 (Vol 26), Issue 3

Dario Babić
2014 (Vol 26), Issue 3

Ivan Lovrić, Dražen Cvitanić, Deana Breški
2014 (Vol 26), Issue 2
Free flow speed is used as a parameter in transportation planning and capacity analysis models, as well as speed-flow diagrams. Many of these models suggest estimating free flow speed according to measurements from similar highways, which is not a practical method for use in B&H. This paper first discusses problems with using these methodologies in conditions prevailing in B&H and then presents a free flow speed evaluation model developed from a comprehensive field survey conducted on nine homogeneous sections of state and regional roads.

Gorkem Gulhan, Huseyin Ceylan, Ozgur Baskan, Halim Ceylan
2014 (Vol 26), Issue 2
Policy makers and planners evaluate the implementation of the urban public transport (UPT) planning studies in terms of some objective measures such as load factor, mean volume per trip, capacity usage ratio and total capacity. In some cases, improving these measures may lead an unforeseen decrease on accessibility to the opportunities in terms of UPT users. Thus, this study aims to evaluate Potential Accessibility (PA) as an efficiency measure in decision stage of UPT planning. It widely depends on fieldwork, surveys, data inventories and existing plans. In this context, a comprehensive UPT planning has been carried out through VISUM traffic simulation software by taking the PA into account, and a four-step UPT planning procedure has been proposed. The results showed that PA may alternatively be used as an evaluation instrument in decision stage of UPT planning while the objective measures are insufficient to represent the effectiveness of alternative scenarios.

Amir Reza Mamdoohi, Mohsen Fallah Zavareh, Christer Hydén, Trond Nordfjærn
2014 (Vol 26), Issue 2
Conflicts in traffic stream have been detected by different safety performance indicators. This study aims to empirically investigate the differences between different indicators in detecting rear-end conflicts and assessing the risk in an uninterrupted flow. Micro-level data of a 24-hr traffic stream (including 6,657 vehicles) were captured using inductive loop detectors installed on a rural freeway section. Different indicators (Time Headway (H), Time to Collision (TTC), Proportion of Stopping Distance (PSD), Deceleration Rate to Avoid Collision (DRAC) and Stopping Distance Index (SDI)) were used to measure each car following event in a bivalent state (safe/unsafe). Unsafe events associated with each indicator were detected and common unsafe events characterized by different indicators were identified. Temporal distributions of rear-end collision risks associated with each indicator at 15-min intervals were also compared. Finally, the 15-min risk values based on different indicators were categorized and compared across three levels (Low, Medium and High). Data mining and statistical techniques showed that while SDI is the single most conservative indicator, DRAC and TTC detect a few risky events but very equal ones. In almost all conflicts associated with TTC, headway is still lower than the critical threshold. However, there exist considerable risky events based on headway which are still safe according to TTC. Comparison of PSD and TTC also declares that almost all conflicts associated with TTC are also risky according to PSD.

Nedal Taisir Ratrout, Yazan F Issa
2014 (Vol 26), Issue 2

Recently, Variable Message Signs (VMS) were introduced in Saudi Arabia and their reliability under local environment is being tested. This paper aims to evaluate the possible response of the drivers to VMS when used for messages related to traffic conditions. A major arterial in Al-Khobar city in Saudi Arabia with a massive VMS board was selected for this paper. The evaluation process started by interviewing drivers selected randomly from the study area. About 77% of the interviewed drivers indicated positive attitude toward messages requesting change of route. The drivers’ interviews demonstrated statistical relationship between the degree of response to messages requesting change of route and the reason for such request. The maximum response was for messages related to accidents, roadwork activities, and traffic congestion. A field experiment was also conducted along the studied arterial. It was found that VMS statistically increased the percentage of diverted traffic during specific peak periods.

Rok Marsetič, Darja Šemrov, Marijan Žura
2014 (Vol 26), Issue 2

The basic principle of optimal traffic control is the appropriate real-time response to dynamic traffic flow changes. Signal plan efficiency depends on a large number of input parameters. An actuated signal system can adjust very well to traffic conditions, but cannot fully adjust to stochastic traffic volume oscillation. Due to the complexity of the problem analytical methods are not applicable for use in real time, therefore the purpose of this paper is to introduce heuristic method suitable for traffic light optimization in real time. With the evolution of artificial intelligence new possibilities for solving complex problems have been introduced. The goal of this paper is to demonstrate that the use of the Q learning algorithm for traffic lights optimization is suitable. The Q learning algorithm was verified on a road artery with three intersections. For estimation of the effectiveness and efficiency of the proposed algorithm comparison with an actuated signal plan was carried out. The results (average delay per vehicle and the number of vehicles that left road network) show that Q learning algorithm outperforms the actuated signal controllers. The proposed algorithm converges to the minimal delay per vehicle regardless of the stochastic nature of traffic. In this research the impact of the model parameters (learning rate, exploration rate, influence of communication between agents and reward type) on algorithm effectiveness were analysed as well.

Aleksandar Nikolić, Danilo Nikolić, Emilija Nikolić, Vesna Vujačić
2014 (Vol 26), Issue 2

Traffic is the most significant noise source in urban areas. The village of Kamenari in Boka Kotorska Bay is a site where, in a relatively small area, road traffic and sea (ferry) traffic take place at the same time. Due to the specificity of the location, i.e. very rare synergy of sound effects of road and sea traffic in the urban area, as well as the expressed need for assessment of noise level in a simple and quick way, a research was conducted, using empirical methods and statistical analysis methods, which led to the creation of acoustic model for the assessment of equivalent noise level (Leq). The developed model for noise assessment in the Village of Kamenari in Boka Kotorska Bay quite realistically provides data on possible noise levels at the observed site, with very little deviations in relation to empirically obtained values.

Chuan Ding, Chao Liu, Yaoyu Lin, Yaowu Wang
2014 (Vol 26), Issue 2

Reducing car trips and promoting green commuting modes are generally considered important solutions to reduce the increase of energy consumption and transportation CO2 emissions. One potential solution for alleviating transportation CO2 emissions has been to identify a role for the employer through green commuter programs. This paper offers an approach to assess the effects of employer attitudes towards green commuting plans on commuter mode choice and the intermediary role car ownership plays in the mode choice decision process. A mixed method which extends the traditional discrete choice model by incorporating latent variables and mediating variables with a structure equation model was used to better understand the commuter mode choice behaviour. The empirical data were selected from Washington-Baltimore Regional Household Travel Survey in 2007-2008, including all the trips from home to workplace during the morning hours. The model parameters were estimated using the simultaneous estimation approach and the integrated model turns out to be superior to the traditional multinomial logit (MNL) model accounting for the impact of employer attitudes towards green commuting. The direct and indirect effects of socio-demographic attributes and employer attitudes towards green commuting were estimated. Through the structural equation modelling with mediating variable, this approach confirmed the intermediary nature of car ownership in the choice process. The results found in this paper provide helpful information for transportation and planning policymakers to test the transportation and planning policies effects and encourage green commuting reducing transportation CO2 emissions.

Gordana Štefančić, Slavko Šarić, Robert Spudić
2014 (Vol 26), Issue 2

Investment in the transport system with the aim of fostering attractiveness and land use in urban structures is of great interest for planners and investors. Investment in urban public transport would especially contribute to revitalising distinct city areas. The samples of high population density and diversified area use are organised around accessible means of urban public transport.

The main objective of this case study was to find an adequate model for the solution of urban public transport on the location Novi Jelkovec in Zagreb after the construction of a new urban settlement, with the aim to revitalise the peripheral parts of the city.

The theoretical assumption on the influence of better organised transport on land use is hereby researched through the example of correction of timetables and reduction of travelling time between nodes on the line in the Novi Jelkovec settlement. In preparing this paper the following methods were used: analysis and synthesis, mathematical and statistical methods, methods of interviewing. The theory of correlation of land use and urban public transport is based on models that develop the “compact city”.

The obtained research results confirm the significance of the correlation between urban land use and urban public transport. It can be concluded that this paper proves the influence of the correlation between land use and urban public transport on the concrete example of Novi Jelkovec. Its implementation could result in solving the concrete traffic problem and along with it a faster urbanisation of the new settlement.

Snežana Radoman Tadić, Slobodan Marko Zečević, Mladen Dragan Krstić
2014 (Vol 26), Issue 2
This paper presents the procedure for logistics system scenario selection for the central business district (CBD) of the city in the phase of significant urban changes. Scenarios are defined in accordance with the overall logistics concept of the city. Conflicting goals of stakeholders (residents, shippers and receivers, logistics providers and city government) generate a vast number of criteria that need to be included when selecting the scenario for the city area logistics system. Due to limited resources and linguistic assessment of criteria, fuzzy extensions of conventional multi-criteria decision-making (MCDM) methods were used. Fuzzy 'analytical hierarchy process' (FAHP) is applied to determine the relative weights of evaluation criteria, and fuzzy 'technique for order preference by similarity to ideal solution' (FTOPSIS) is applied to rank the logistics systems scenarios. This paper contributes to the literature in the field of city logistics (CL), as it applies the integrated FAHP-FTOPSIS method for the evaluation of scenarios, which are also integrated combinations of different CL initiatives. The integrated combined approach proved to be accurate, effective and a systematic tool for the decision support in the process of selecting CBD logistics scenarios.

Željko Kanović, Vladimir Bugarski, Todor Bačkalić
2014 (Vol 26), Issue 1
This paper presents the comparison of some well-known global optimization techniques in optimization of an expert system controlling a ship locking process. The purpose of the comparison is to find the best algorithm for optimization of membership function parameters of fuzzy expert system for the ship lock control. Optimization was conducted in order to achieve better results in local distribution of ship arrivals, i.e. shorter waiting times for ships and less empty lockages. Particle swarm optimization, artificial bee colony optimization and genetic algorithm were compared. The results shown in this paper confirmed that all these procedures show similar results and provide overall improvement of ship lock operation performance, which speaks in favour of their application in similar transportation problem optimization.

Li Li, Lijun Sun, Guobao Ning, Shengguang Tan
2014 (Vol 26), Issue 1
A feasible pavement crack detection system plays an important role in evaluating the road condition and providing the necessary road maintenance. In this paper, a back propagation neural network (BPNN) is used to recognize pavement cracks from images. To improve the recognition accuracy of the BPNN, a complete framework of image processing is proposed including image preprocessing and crack information extraction. In this framework, the redundant image information is reduced as much as possible and two sets of feature parameters are constructed to classify the crack images. Then a BPNN is adopted to distinguish pavement images between linear and alligator cracks to acquire high recognition accuracy. Besides, the linear cracks can be further classified into transversal and longitudinal cracks according to the direction angle. Finally, the proposed method is evaluated on the data of 400 pavement images obtained by the Automatic Road Analyzer (ARAN) in Northern China and the results show that the proposed method seems to be a powerful tool for pavement crack recognition. The rates of correct classification for alligator, transversal and longitudinal cracks are 97.5%, 100% and 88.0%, respectively. Compared to some previous studies, the method proposed in this paper is effective for all three kinds of cracks and the results are also acceptable for engineering application.

Baozhen Yao, Ping Hu, Mingheng Zhang, Xiaomei Tian
2014 (Vol 26), Issue 1
This paper deals with a real-life vehicle delivery routing problem, which is a seafood product delivery routing problem. Considering the features of the seafood product delivery routing problem, this paper formulated this problem as a multi-depot open vehicle routing problem. Since the multi-depot open vehicle routing problem is a very complex problem, a method is used to reduce the complexity of the problem by changing the multi-depot open vehicle routing problem into an open vehicle routing problem with a dummy central depot in this paper. Then, ant colony optimization is used to solve the problem. To improve the performance of the algorithm, crossover operation and some adaptive strategies are used. Finally, the computational results for the benchmark problems of the multi-depot vehicle routing problem indicate that the proposed ant colony optimization is an effective method to solve the multi-depot vehicle routing problem. Furthermore, the computation results of the seafood product delivery problem from Dalian, China also suggest that the proposed ant colony optimization is feasible to solve the seafood product delivery routing problem.

Ljupko Šimunović, Davor Brčić
2014 (Vol 26), Issue 1

Andriela Vitić-Ćetković, Sanja Bauk
2014 (Vol 26), Issue 1

The paper positions the passenger sea ports in the context of cruise tourism on the basis of e-services they offer. The e-services of eleven passenger ports are categorized and then quantitatively evaluated by binary and ranking approaches. In general, the port e-services might be categorized according to their functionality as navigational, ship and passenger-related ones, logistics, business, marketing, entertainment, security, safety, environmental, etc. These services can be bidirectional informational and/or transactional. In this paper, only those port e-services related directly to the passengers’ needs, within the frame of cruise tourism, are taken into consideration and categorized as core, or as value-added ones, and as informational and/or transactional ones. Then, each of them is assigned an appropriate binary value (0/1), depending on whether the considered passenger port offers the related e-service or not. These values are employed in the evaluation of the analyzed passenger port e-services offered, and as a base for their positioning. The appropriate weights coefficients, obtained by ranking (Saaty method), were used in the process of the considered port final positioning on the cruise tourism e-market. Some additional analyses and recommendations in the direction of further positioning and promotion of the port of Kotor (Montenegro), as rising cruise tourism port (destination), are given as well.

Mario Miler, Damir Medak, Dražen Odobašić
2014 (Vol 26), Issue 1

In the field of geoinformation and transportation science, the shortest path is calculated on graph data mostly found in road and transportation networks. This data is often stored in various database systems. Many applications dealing with transportation network require calculation of the shortest path. The objective of this research is to compare the performance of Dijkstra shortest path calculation in PostgreSQL (with pgRouting) and Neo4j graph database for the purpose of determining if there is any difference regarding the speed of the calculation. Benchmarking was done on commodity hardware using OpenStreetMap road network. The first assumption is that Neo4j graph database would be well suited for the shortest path calculation on transportation networks but this does not come without some cost. Memory proved to be an issue in Neo4j setup when dealing with larger transportation networks.

Meng Meng, Chunfu Shao, Jingjing Zeng, Chunjiao Dong
2014 (Vol 26), Issue 1

This paper presents a dynamic traffic assignment (DTA) model for urban multi-modal transportation network by con­structing a mesoscopic simulation model. Several traffic means such as private car, subway, bus and bicycle are con­sidered in the network. The mesoscopic simulator consists of a mesoscopic supply simulator based on MesoTS model and a time-dependent demand simulator. The mode choice is si­multaneously considered with the route choice based on the improved C-Logit model. The traffic assignment procedure is implemented by a time-dependent shortest path (TDSP) al­gorithm in which travellers choose their modes and routes based on a range of choice criteria. The model is particularly suited for appraising a variety of transportation management measures, especially for the application of Intelligent Trans­port Systems (ITS). Five example cases including OD demand level, bus frequency, parking fee, information supply and car ownership rate are designed to test the proposed simulation model through a medium-scale case study in Beijing Chaoy­ang District in China. Computational results illustrate excel­lent performance and the application of the model to analy­sis of urban multi-modal transportation networks.

Ting-Wei Lin, Chia-Yen Lin, Wen-Ho Hsu
2014 (Vol 26), Issue 1

This study proposes a behavioural intention model that integrates information quality, response time, and system accessibility into the original technology acceptance model (TAM) to investigate whether system characteristics affect the adoption of Web-based advanced traveller information systems (ATIS). This study empirically tests the proposed model using data collected from an online survey of Web-based advanced traveller information system users. Con­firmatory factor analysis (CFA) was performed to examine the reliability and validity of the measurement model, and structural equation modelling (SEM) was used to evaluate the structural model. The results indicate that three system characteristics had indirect effects on the intention to use through perceived usefulness, perceived ease of use, and attitude toward using. Information quality was the most im­portant system characteristic factor, followed by response time and system accessibility. This study presents implica­tions for practitioners and researchers, and suggests direc­tions for future research.

pengcheng yuan, zhicai juan
2014 (Vol 26), Issue 1

The assumption about travellers’ route choice behaviour has major influence on the traffic flow equilibrium analysis. Previous studies about the travellers’ route choice were mainly based on the expected utility maximization theory. However, with the gradually increasing knowledge about the uncertainty of the transportation system, the researchers have realized that there is much constraint in expected util­ity maximization theory, because expected utility maximiza­tion requires travellers to be ‘absolutely rational’; but in fact, travellers are not truly ‘absolutely rational’. The anticipated regret theory proposes an alternative framework to the tra­ditional risk-taking in route choice behaviour which might be more scientific and reasonable. We have applied the antici­pated regret theory to the analysis of the risk route choosing process, and constructed an anticipated regret utility func­tion. By a simple case which includes two parallel routes, the route choosing results influenced by the risk aversion degree, regret degree and the environment risk degree have been analyzed. Moreover, the user equilibrium model based on the anticipated regret theory has been established. The equivalence and the uniqueness of the model are proved; an efficacious algorithm is also proposed to solve the model. Both the model and the algorithm are demonstrated in a real network. By an experiment, the model results and the real data have been compared. It was found that the model re­sults can be similar to the real data if a proper regret degree parameter is selected. This illustrates that the model can better explain the risk route choosing behaviour. Moreover, it was also found that the traveller’ regret degree increases when the environment becomes more and more risky.

Xiao-Jun Yu, Chun-Hua Fang
2014 (Vol 26), Issue 1
The efficiency loss of mixed equilibrium associated with two categories of users is investigated in this paper. The first category of users are altruistic users (AU) who have the same altruism coefficient and try to minimize their own perceived cost that assumed to be a linear combination of selfish com­ponent and altruistic component. The second category of us­ers are Logit-based stochastic users (LSU) who choose the route according to the Logit-based stochastic user equilib­rium (SUE) principle. The variational inequality (VI) model is used to formulate the mixed route choice behaviours associ­ated with AU and LSU. The efficiency loss caused by the two categories of users is analytically derived and the relations to some network parameters are discussed. The numerical tests validate our analytical results. Our result takes the re­sults in the existing literature as its special cases.

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