Different types of pedestrians exhibit different speed characteristics and heterogeneity. In the case of mixed pedestrian flow at signalised intersections, pedestrian traffic flow modelling is important in research of the con-ditions at signalised intersections and the evaluation of services for pedestrians. The characteristics of pedestri-an traffic flow at signalised intersections were investi-gated in this study against the background of pedestrian heterogeneity using videos of pedestrians crossing three signalised intersections in Chongqing recorded in a field survey. The pedestrian walking speeds were manually ex-tracted from the videos and used as the data basis for dis-tinguishing pedestrian heterogeneity. The walking speed data of three types (young, middle-aged, and elderly) of pedestrians at different pedestrian flows were obtained by using a microsimulation software. Based on this, a pe-destrian traffic flow model for mixed-type pedestrians at signalised intersections was established and verified by actual cases. In comparison with the HCM model, the model outperforms the HCM model overall in practical applications, indicating its strong applicability and reli-ability.
Most studies investigate the benefit of public trans-port service from either the perspective of the operators or the public individually, failing to bind them together. Furthermore, they have not considered the significance of the government in quantifying the benefit. This pa-per explores the comprehensive benefit of public trans-port service from the perspectives of three stakeholders; namely, the operators, the public, and government. We develop a comprehensive benefit evaluation tool that is able to quantify production efficiency, service effect, and environmental effect, and test the effectiveness of the tool through a case study in 36 central cities of China. A network data envelopment analysis (NDEA) is used to evaluate the efficiency of the production and service sub-process, and comprehensive benefits. The results re-veal the following: (1) during the period 2010–2017, the production efficiency in 36 central cities showed a down-ward trend; (2) the service effectiveness did not change considerably from 2010 to 2013 but declined gradual-ly during the period 2014–2017; (3) the comprehensive benefits rarely changed during the period 2010–2013, but gradually got worse in response to reductions in the production efficiency and service effectiveness during the period 2014–2017. This study offers a robust tool to mea-sure the benefits of public transport in China for better decision-making, in terms of transit operation and man-agement.
Unconventional geometric designs such as continu-ous-flow intersections, U-turns, and contraflow left-turn lanes have been proposed to reduce left-turn conflicts and improve intersection efficiency. Having a waiting area at a signalised intersection is an unconventional de-sign that is used widely in China and Japan to improve traffic capacity. Many studies have shown that waiting areas improve traffic capacity greatly, but few have con-sidered how to improve the benefits of this design from the aspect of signal optimisation. Comparing the start-up process of intersections with and without waiting areas, this work explores how this geometric design influenc-es vehicle transit time, proposes two signal optimisation strategies, and establishes a unified capacity calculation model. Taking capacity maximisation as the optimisation function, a cycle optimisation model is derived for over-saturated intersections. Finally, the relationship among waiting-area storage capacity, cycle time, and traffic ca-pacity is discussed using field survey data. The results of two cases show that optimising the signal scheme helps reduce intersection delays by 10–15%.
The problem of choosing only one relevant safety performance indicator for the purpose of comparing and assessing road safety situations has been the subject of many recent research studies. This paper shows the concept of creating a composite exposure index based on available data. The procedure of creating a model for calculating this indicator is based on the analysis of quality of individual exposure indicators and the size of their impact on the direct safety performance indicators – number of road crashes and their consequences. The following four models (TOPSIS EQUAL, TOPSIS CRIT-IC, PROMETHEE EQUAL, PROMETHEE CRITIC) for determining weighted coefficients of the individual indi-cators that participate in the creation of the composite exposure index have been analysed in this paper. The method used for defining the composite exposure index is the “high-efficiency method” based on which the final shape of the model for defining the composite exposure index has been defined. The main aim of this paper is to create a model for defining the composite index of traffic exposure. The final outcome is to provide an opportuni-ty to evaluate and rank traffic safety levels based on the unique road traffic risk.
Origin-destination (OD) matrices provide transportation experts with comprehensive information on the number and distribution of trips. For comparing two OD matrices, it is vital to consider not only the numerical but also the structural differences, including trip distribution priorities and travel patterns in the study region. The mean structural similarity (MSSIM) index, geographical window-based structural similarity index (GSSI), and socioeconomic, land-use, and population structural similarity index (SLPSSI) have been developed for the structural comparison of OD matrices. These measures have undeniable drawbacks that fail to correctly detect differences in travel patterns, therefore, a novel measure is developed in this paper in which geographical, socioeconomic, land-use, and population characteristics are simultaneously considered in a structural similarity index named GSLPSSI for comparison of OD matrices. The proposed measure was evaluated using OD matrices of smartphone Global Positioning System (GPS) data in Tehran metropolitan. Also, the robustness of the proposed measure was verified using sensitivity analysis. GSLPSSI was found to have up to 21%, 15%, and 9% higher accuracy than MSSIM, GSSI, and SLPSSI, respectively, regarding structural similarity calculation. Furthermore, the proposed measure showed 7% higher accuracy than SLPSSI in the structural similarity index of two sparse OD matrices.
The taxi system is one of the most famous and de-veloped subsystems of flexible passenger transport. To reach the goal of the system achieving maximum produc-tion efficiency, the management focus is directed at users and service quality (SQ). The SQ can have several forms: expected, targeted, delivered, and perceived SQ. We ex-amine the expected SQ, expressed through the users’ at-titudes about the importance of the defined parameters of the SQ, which represent the users’ expectations from the taxi system. The analysis included the data from the conducted studies in three selected taxi systems. The aim of this paper was to determine the effect of market and selected user characteristics on the user expectations, applying the Chi-Square Test. We conclude that the spe-cific market and certain user characteristics affect the user expectations of the taxi system. There is a moderate effect on the employed users, pensioners, and daily users of the taxi system. When it comes to the users who use the taxi system several times a month and week, there is a less significant effect. Other user categories have no sig-nificant correlation with the selection of the parameters of the SQ in the taxi system.
Evaluating air transport service quality is fundamen-tal to ensure acceptable quality standards for users and improve the services offered to passengers and tourists. In the transportation literature there is a wide range of studies about the evaluation of public transport service quality based on passengers’ perceptions; however, more recently, the evaluation of air transport service quality is becoming a relevant issue. Evaluating service quality in air transport sector represents a more stimulating chal-lenge, given the complexity of air transport system in re-gards to the other systems; in fact, air transport service is characterised by a great variety of service aspects relat-ing to services offered by the airlines and provided by the companies managing airports. The complexity of such a service requires a deep investigation on the methods adopted for collecting and analysing the data regarding passengers’ perceptions. We propose this paper just for treating these interesting aspects and to provide an ex-haustive literature review of the studies analysing ser-vice quality from the passengers’ point of view, where the opinions of the passengers are collected by the Customer Satisfaction Surveys (CSS). We decided to select papers published within the last decade (2010–2020) in journals indexed in important databases such as Scopus and WoS.
Walking is an environment-friendly trip mode and can help ease the congestion caused by automobiles. Proper design of pedestrian facilities that promotes effi-ciency and safety can encourage more people to choose walking. Upstream detection (UD) strategy is proposed by previous studies to reduce pedestrian waiting time at mid-block crosswalk (MBC). This paper applied UD strategy to MBC under mixed traffic circumstance where the crosswalk serves both pedestrians and non-motor us-ers. Traffic data was collected from an MBC in the city of Nanjing, China. Simulation models were developed by using the VISSIM software and its add-on module Vehicle Actuated Programming (VAP). The models were catego-rised by the volume and composition of pedestrians and non-motor users. Models were simulated according to different experimental schemes to explore the effective-ness of the UD strategy under mixed traffic circumstance. T-test and analysis of variance (ANOVA) were used to interpret the simulation results. The main conclusions of this paper are that the UD strategy is still effective at the MBC with a mixed traffic circumstance despite the pro-portion of non-motor users. However, as the proportion of non-motor users becomes higher, the average delay of pedestrians and non-motor users will increase compared to pure pedestrian flow.
The reasonable placement of the advance guide signs (AGSs) is important in improving driving efficiency and safety when exiting an expressway. By analysing the lane-changing process when approaching an exit on new two-way eight-lane expressways, we modified the tradi-tional AGS model lane-change distance formula. To this end, a field experiment was designed to explore the lane-change traversal time at the free flow condition (LOS 1). Considering the limitations of the experimental equip-ment, lane change distance at the worst levels of service was explored using VISSIM simulation. The results show that the eight-lane changing distance based on modified theoretical calculations, revealed a minor difference with VISSIM simulation in free flow condition. Further-more, placement distance at the worst levels of service are discussed. Then placement distance of all-level AGSs is recommended to be 3 km, 2 km, 1.2 km, and 0.8 km, considering the driver's short-term memory attenuation calculation formula. Determining the two-way eight-lane AGS placement distance from the perspective of LOS can provide a basis on which to supplement the existing stan-dards and references for the AGS placement distance af-ter the expressway expansion in China.
According to models commonly used in practice, the capacity of roundabouts largely depends on the value of critical headway. The value of critical headway depends on the characteristics of vehicles, driving conditions, and geometric characteristics of intersections, but also on driver behaviour. Driver behaviour is the result of many factors that depend on the influence of the local environment, driver habits, mentality, etc. Accordingly, to calculate the capacity of roundabouts within the op-erational and planning analyses of roundabouts more accurately, it is necessary to use data that correspond to local conditions. In this paper, the critical headway was estimated at five urban single-lane roundabouts using five methods: Harders’, Logit, Raff’s, Wu’s, and the max-imum likelihood method. In order to determine which of the stated methods provides the most realistic estimate of critical headway, a comparison of field capacity values with theoretical capacity values was performed. Based on the comparative analysis performed in MATLAB, as well as the calculation of percentage prediction error, it was found that the Harders' method provides the most accurate estimate of critical headway at observed round-abouts in two cities in Bosnia and Herzegovina. Due to the similarity in the design of roundabouts and driver be-haviour, the results obtained in this paper can be applied in the surrounding countries, i.e., Southeast Europe
Level of service (LOS) classifications of traffic oper-ational conditions play a significant role in roadway-im-provement funding decisions. Traveller perception of LOS should be consistent with traffic analysis values to avoid undermining the public confidence in the transpor-tation agency decisions. Research methods to study trav-eller perceptions range from in-vehicle videos to focus groups and surveys. These methods have different advan-tages, but all suffer from time and/or cost inefficiencies for collecting data sets across a wide range of operating conditions. This paper describes a novel method to study this topic with increased time and cost efficiency. This new method combines traffic microsimulation and 3-D visualisation capabilities. The focus of this paper is to provide guidance on how to apply traffic microsimula-tion and computer 3-D visualisation to evaluate highway trip quality from a traveller’s perspective. It discusses the creation of the simulation environment to produce a real-istic view from the vehicle’s cabin interior, including the network creation, landscaped area, dashboard speedom-eter, and rear-view mirror. The authors also propose an automated method for choosing an appropriate vehicle within the simulated traffic stream, such that the desired overall traffic stream conditions are conveyed to the trav-eller vehicle within the field of view.
The contribution includes the necessity to analyse the potential of the regions in terms of rail passenger transport. The main research goal is to propose a new concept of determination and evaluation of the particu-lar factors, which evaluate the region potential. Several research methods are used in research, for example the brainstorming methods, methods of expert estimate, and especially point evaluation method. Firstly, the factors influencing the traffic potential are defined and exam-ined. Secondly, specific ways of monitoring and evaluat-ing particular factors are proposed. The research results form the basis of a new methodology for traffic potential determination in regions. Subsequently the mentioned methodology is applied in practice to the selected region-al railway line in Slovak Republic. The potential of this region is expressed by coefficient values of the chosen factors. For example, coefficient of the number of inhab-itants is 2.69 and the average value of the adjacent co-efficient of the railway stations and stops availability is 1.92. The details are explained in the fourth chapter. The proposals and outputs including practical application represent a new innovative way for region evaluation which has so far not been used anywhere. It can help plan and organise traffic service in the regions.
Accelerating Discoveries in Traffic Science |
2024 © Promet - Traffic&Transportation journal