The performance of tramway service from the users' viewpoint: A comparative analysis between two Moroccan cities

The Moroccan government has recently promoted sustainable public transport projects such as tramway services namely in the two largest cities of country, Casablanca and Rabat-Salé. Since its launch, the tramway service is in-creasingly present in citizens' daily lives in both cities. To maintain its attractiveness, operators and transport authori-ties should examine the performance of tramway service from user’s point of view. That is, an in-depth understanding of how passengers perceive service quality and what make them satisfied. The purpose of this study is to compare the performance of tramway service in the two cities based on the opinions of a sample size of 613 and 435 individuals in each city. The outcome of this peer comparison allows to determine the strengths and weaknesses of provided service and identify priorities for improvement in each city. Regarding the methodology, we adopted a two-step approach to achieve our research purpose. The first stage intends to compare users' perceptions regarding Service Quality Attrib-utes (SQAs) and overall satisfaction and to identify any significant differences between the two cities. To this end, we applied, in the first stage, a student t-test of two independent samples. The second stage employs an ordered probit regression model to identify the most important SQA; i.e., which most influence the overall satisfaction, and improve-ments priorities for the current service tramway. The results showed that, in average, passengers found service quality as good and are satisfied with tramway service in both cities. Tram vehicles’ is the best appreciated service attribute in both cities while Comfort in Rabat-Salé and Lines’ connectivity in Casablanca are the least appreciated. Moreover, the service performance of Rabat-Salé tramway exceeds that of Casablanca tramway in terms of service Availability, ser-vice Reliability, Fares level, Tram vehicle, Drivers’ competence, Lines’ connectivity, and overall satisfaction. On the other hand, we found that among top six important attributes, Reliability and Administrators should be prioritized for improvement in Casablanca; and staff, Lines, Comfort, and Administrators in Rabat-Salé. Results showed that im-provements in all these service aspects would increase significantly overall user’s satisfaction.

Modelling of the shape of railway transition curves from the point of view of passenger comfort

In the past, railway transition curves were not used. Instead of it, a simple connection of the straight track and circular arc was applied. Nowadays, such simplicity is not allowed due to the increasing vehicle operating velocities. It is mainly visible in the high-speed train lines, where long curves are used. The article aims to develop a new shape of railway transition curves for which passenger travel comfort will be as high as possible. Considerations in this paper concern the polynomials of 9th- and 11th-degrees, which were adopted to the mathematical model of the mentioned shape of curves. The study's authors applied a 2-axle rail vehicle model combined with mathematically understood optimisation methods. The advanced vehicle model can better assign the dynamical properties of railway transition curves to freight and passenger vehicles. The mentioned model was adopted to simulate rail vehicle movement in both cases of the shape of transition curves and the shape of circular arc (for comparison of the results). Passenger comfort, described by European Standard EN 12299, was used as the assessment criterion. The work showed that the method using the 2-axle railway vehicle model combined with mathematically understood optimisation works correctly, and the optimisation of the transition curve shape is possible. The current study showed that the 3rd-degree parabola (the shape of the curve traditionally used in railway engineering) is not always the optimum shape. In many cases (especially for the long curves), the optimum shape of curves is between the standard transition curves and the linear curvature of the 3rd-degree parabola. The new shapes of the railway transition curves obtained when the passenger comfort is taken into account result in new railway transition curves shapes. In the authors' opinion, the results presented in the current work are a novelty in optimisation and the properties assessment of railway transition curves.

Research on the effectiveness of alternative propulsion sources in high-tonnage cargo transport

The progressive degradation of the environment makes implementing pro-ecological solutions in various areas of our lives more meaningful. These measures also apply to transport, responsible for around 30% of total carbon dioxide emissions in the EU. Implementing ecological solutions in road transport encounters various barriers resulting mainly from the specificity of transport tasks. One of the most promising solutions in the high-tonnage road transport sector seems to be LNG-fueled engines, which allow for similar operating conditions to traditional combustion vehicles. The article aims to identify the environmental benefits of the use of high-tonnage LNG-fueled vehicles in freight transport and to conduct a comprehensive assessment of the economic efficiency of this solution. The article assesses the effectiveness of using an LNG-fueled vehicle and a diesel-fueled vehicle that meets the highest exhaust emission standard in high-tonnage transport, both in terms of economy and an impact of these solutions on the environment. The research was carried out on a given route, taking into account variants of vehicle manning and simulations of transport cycle time. In conclusion, a discussion of the obtained results was carried out, emphasizing the factors determining the profitability of using high-tonnage vehicles with LNG drive or its lack. Regardless of the indicated lack of clarity in the economic assessment of the effectiveness of LNG drives in high-tonnage vehicles, the identified environmental benefits from implementing these solutions seem to be quite unequivocal. Thus, it should be expected that in the event of loss of economic competitiveness of these solutions, appropriate fiscal instruments should be used - especially since LNG drives in the policies of individual countries are considered pro-ecological solutions.

Combined optimisation and MCDA based solution of the tram depot location problem

This paper deals with an issue of technical facilities location in a public transport system. The decision problem is formulated as a selection of the most advantageous alternative, i.e. the location of a new tram depot among the already existing facilities of this type. The selection is preceded by the evaluation of the alternatives. The assessment is not a trivial task, because there are many groups of interest with usually contradictory points of view. Therefore, the evaluation of the new tram depot locations should represent different aspects, e.g., economical, technical, environmental, and organizational. To handle such a complex decision problem the authors propose a methodology, which is a composition of the optimisation and multiple criteria evaluation techniques. The developed methodology is experimentally applied to the selection of one out of five tram depot locations in the public transport system of the city of Poznan, Poland. All the computational experiments are performed by means of optimization and multiple criteria decision aiding (MCDA) methods and tools, i.e. a linear optimization engine Solver Premium Platform and AHP method with its application AHORNsimple. The calculations are the basis for recommending the location of a new depot in the central part of the transport system network, which is a reasonable solution taking into account, e.g. the proximity of the main railway line, the possibility of triple distribution of the transport means from depot. The proposed methodology of the decision problem solution gives also an opportunity to create the hierarchy of considered tram depot locations as well as to compare the position in the ranking of the best solution with the existing one. Since the proposed methodology assumes the selection of the most suitable MCDA method to the problem under consideration and the decision maker’s preferen¬ces, it guarantees that the result of analysis becomes reliable and the decision aiding process is credible.

Virtual reality as a new tool for transport data collection

Transport studies that adopt complex analyses present methodological challenges that lead to the use of innovative techniques to address the limitations of traditional methods. In the Latin American context, people consider security as a relevant variable in their daily lives. Thus, when people travel around the city and choose a mode of transport, secu-rity becomes an important factor and should therefore be included in transport studies. However, the definition of security in terms of transport in the Colombian context remains unclear. Therefore, we examined the security percep-tion effect on transport mode choice by addressing security as a latent variable consisting of three elements: environ-ment, subject and transport mode. We proposed the use of virtual reality (VR) to recreate travel routes and offer partic-ipants a scenario of choice closer to the natural conditions of a trip. The participants were provided routes in the form of immersive 3D videos recreating natural trip conditions to identify their choices and travel behaviour. Recordings were made of daily scenarios and existing urban environments portraying real and active modes of transport, giving respondents an almost-natural experience. The use of 360-degree immersive videos offers a multisensory experience allowing both the capture of socioeconomic and travel information and the collection of journey perception. The experiment evaluated two environments in Medellín, Colombia (secure (E1) and insecure (E2)) and studied the effects of lighting conditions (day (D) and night (N)). A total of four videos (E1D, E1N, E2D and E2N) depicting six transport modes in tandem were assessed by 92 participants from Medellín and Bogotá, Colombia. We found that environment-associated security perception varies depending on the time of the journey (day/night) and one’s familiarity with the environment. The research results position VR as a tool that offers high potential to support transport studies. We found that people’s movements, gestures and expressions while participating in the VR experiments resembled what was expected from journeys in reality. VR constitutes a relevant tool for transport studies, as it allows for an assessment of active transport mode perceptions. It prevents participants from being exposed to the risk associated with travel to specific places and carries out several routes in different transport modes even when participants cannot or have never undertaken journeys in the modes under assessment.

Estimation of critical gaps and follow-up times at median uncontrolled T-intersection

The efficiency of the entire transportation system depends on the capacity of the individual elements that make up the given network. Point-type elements of the road and street network include intersections of different types. Critical gaps and follow-up times related to individual movements are important determinants of the capacity of such objects. There are many ways to estimate such times. The article discusses the assumptions and scheme one of them - the Siegloch method. The objective of the article is to analyze the process of determining critical gaps and follow-up times at the median uncontrolled T-intersections that are rare in the road and street network and have been studied to a limited extent. The commonly used HCM, HBS, and Polish (MOP SBS) methods in their current form do not consider the speci-ficity of such intersections and thus may not give reliable results. Due to their characteristics in terms of geometry conditions, there is a need for an individual approach to estimate both critical gaps and follow-up times. The article contains the results of empirical research conducted on a selected real object in the Upper Silesian agglomeration in Poland. The intersection under study is located in one of the central districts of Katowice city, in the built-up area serving commercial and service functions. The analysis of the behavior of individual drivers waiting for the possibility to continue driving was conducted separately for each minor traffic movement. The values of critical gaps and follow-up times were determined for all four subordinate movements. The values obtained are different from those contained in the Polish manual, which is recommended for use. The research should be considered as pilot studies that justify the need to develop a separate approach to the estimation of the critical gaps and follow-up times at median uncontrolled T-intersections.

Study of the two-rotor electric motor of a drive of vehicle drive wheels

In recent years, electric and hybrid vehicles have taken more and more attention due to their apparent advantages in saving fuel resources and reducing harmful emissions into the environment. Even though electric vehicles can solve the ecological problem, their operation is faced with a number of inconveniences associated with a limited driving distance from a single charge due to limited storage of energy from an independent power source and a lack of the required service and repair infrastructure. In hybrid and electric vehicles one of the main parameters is the curb weight, which affects energy consumption, vehicle speed, stability, controllability and maneuverability. In this regard, leading car manufacturers use parts with a low specific weight (non-metallic, aluminum alloys, etc.) in the design and also exclude some units from the design. Due to these technical solutions, the vehicle's operating is improved. One of the groups of parameters to be defined when designing a new electric vehicle is the parameters relating to the electric motor. The purpose of the article is determination of the mechanical characteristics of a two-rotor electric motor during magnetic flux control and assessment of the possibility of organizing the drive of the drive wheels of the vehicle. The electric motor has two mechanically independent outputs. For the study, an electrical equivalent diagram has been developed for the given two-rotor electric motor. A simulation model of the equivalent diagram has been built. Simulating the interaction processes of the rotors with the stator made it possible to obtain data for building the mechanical characteristics for each output of the electric motor. Analysis and processing of the mechanical characteristics data of the electric motors showed the conformity and the range of changes in the torque on each of the rotors when changing their slip and revolution, which are required when building algorithms for the operation of electric motor control systems as part of drives for various purposes. Analysis of the simulation results made it possible to assess the possibility of using the considered two-rotor electric motor for the drive of drive wheels in an electric and hybrid wheeled vehicle.

The relationship between bicycle traffic and the development of bicycle infrastructure on the example of Warsaw

The article presents the relationship between the intensity of bicycle traffic volume and the development of bicycle infrastructure on the example of Warsaw. There has been a big increase in cycling over the last decade. At the same time, the linear and point bicycle infrastructure developed very strongly. Similar trends are also observed in other cities in Poland. The article presents the types of infrastructure available to cyclists. Then, the method of assessing the bicycle infrastructure is presented, taking into account the five features of good bicycle infrastructure: cohesion, directness, attractiveness, safety and comfort. In terms of coherence, the analysis covered the bicycle infrastructure network in the vicinity of the measurement site. The directness was tested by checking the accessibility of several dozen of the most important nodal points of the city's communication network. The attractiveness was examined by checking the availability of public bike stations, bicycle racks and bike-sharing stations. The infrastructure adjusted to the technical class of the road was adopted as a measure of safety. The comfort was checked by analyzing the quality of the road surface, which affects the driving comfort and energy expenditure. All the factors presented impact the cyclist's assessment of the infrastructure. To standardize the assessment rules, an aggregate index of the development of bicycle infrastructure was determined. The analysis was carried out for 10 sample points for four consecutive years. The points were characterized by different bicycle infrastructure, location in the city road network and different results of bicycle traffic measurements. The analysis showed a strong positive relationship between traffic and cycling infrastructure for most of the analyzed places. There was a negative dependence in the case of the construction of alternative routes in relation to the place of traffic measurements. The obtained results are the same as in the works of other authors. However, the effects of work do not allow to determine which of the examined factors is the cause and which is the effect but only show the existing relationship.

Analysis of safety impact of paved shoulder width on Czech secondary roads

Traffic safety is influenced, among other factors, by characteristics of the roads, which include the width of the shoulder. Shoulder width was noted to have a large effect on crash frequency, as well as on traffic speed. In this paper, we focused on paved shoulders. Previous studies confirmed that increasing the width of the paved shoulder is associated with a decrease in crash frequency. However, wider shoulders may encourage higher driving speed, which is related to an increase of impact speed and crash severity – this issue was hypothesized, but not statistically investigated. Thus, conclusions based on crashes and speeds contradict each other, and there is no simple answer to the question of the safety impact of wide shoulders. To address this gap, we analyzed a sample of two most typical categories of Czech secondary roads, which differ only in the paved shoulder width (S9.5 roads with 0.75m-wide shoulder, and S11.5 roads with 1.75m-wide shoulder) and thus present a suitable example for studying the safety impact of paved shoulder width. We used generalized linear models of crash frequency, and multinomial logistic models of crash severity (separately for single-vehicle and multi-vehicle crashes), as well as a statistical test of differences in speed for the two road categories. The results showed that: Firstly, there were fewer crashes on S11.5 roads compared to S9.5 roads; this was true for both single-vehicle and multi-vehicle crashes. Secondly, single-vehicle crashes on S11.5 roads were more severe compared to S9.5 roads; the change of severity in multi-vehicle crashes was not statistically significant. Thirdly, driving speeds on S11.5 roads were approx. by 7 km/h higher compared to S9.5 roads. These findings support the hypothesis of an association between wider shoulders, higher speeds, and increased crash severity, especially in the case of single-vehicle crashes. As a practical solution, various speed management measures, including widening to a 2+1 road, may be recommended.

Assessment of airside aerodrome infrastructure by SAW method with weights from Shannon's interval entropy

Multi-criteria decision support (MCDM) methods are widely used in many areas of science. This applies to economic, social and technical sciences. Implementing activities at the strategic, tactical or operational level requires appropriate tools to support decision-makers. The use of these tools requires the preparation of a decision model along with the formalization of the goal and the acquisition and preparation of data to make the decision accurate. Due to the wide application of MCDM in engineering practice, the article presents their application in air transport. It is an area that is constantly evolving, and all decisions at the strategic level have long-term effects and must be adequately justified. In the paper a compartmental extension of the classical SAW method with weights obtained using the compartmental Shannon entropy was proposed. This paper presents issues concerning the choice of airport layout and describes the problems that occur in determining the cost and capacity of airports. This paper reviews the literature on airport capacity and operations and airside air transport processes and the application of various multi-criteria decision support methods to airport problems. The main part of the article contains an optimization mathematical model aimed at determining the parameters of the elements comprising the airport, on the basis of which a simulation model was developed and a modified method of multi-criteria evaluation of SAW taking into account the interval numbers was presented, in which the set of weights was estimated by the Shannon entropy method. In the application part for 3 variants of the airport arrangement, the parameters were determined in the form of interval numbers and then evaluated using the presented method. The presented numerical example shows that the proposed method is an excellent tool to assist in solving complex decision problems where the data are imprecise and represented by interval numbers.