City Bus Research Articles

Effect of natural gas composition and gas interchangeability on performance and emission characteristics in an air–fuel controlled natural gas engine

In this study, the effect of low-calorie gas on the output performance and efficiency of engines and the emission characteristics was investigated using an 11 L 6-cylinder supercharged engine for city buses. In order to examine the effect of changes in the physical properties of low calorific gas on combustion, the results with simulated low calorific natural gas by the addition of nitrogen were compared to those with reference natural gas fuel. Pure methane (CH4) is also used to investigate the effect of gas composition change on the performance and emission characteristics. The basic performance factors, including torque and thermal efficiency, were compared by varying the engine speed under full-load operating conditions. The trends of exhaust gas emissions were observed and analyzed with respect to the fuel composition.Another purpose of this study is to determine whether the higher heating value (HHV), Wobbe index (WI), and maximum combustion potential (MCP) index are appropriate factors for determining the performance and exhaust condition of the air–fuel controlled engine for the composition of the gas used in this study. It was found that the combustion rate is the most important physical property of the gas, while the MCP does not match the laminar flame speed of low calorific gas fuel and pure CH4. The modified MCP value is presented and is a suitable gas interchangeability index of the engine that controls the air–fuel ratio because it properly reflects the effect of the inert gas in the fuel gas.

Study on the Influence of the Center of Gravity of Fuel Cell City Bus on its Handling Characteristics

The vehicles driven by combustion engine leads to environmental problems because of fossil fuel consumption. In recent years, many policies have adopted to support the development of new energy vehicles, especially battery electric vehicles as the main strategy in China. For the battery electric vehicles, the position of the battery pack can change the centroid position of the vehicle because of its big mass, and it can also change the loading of each tire in the motion, which has important influence on the vehicle handing and stability performance. This article studies the relationship between handling characteristic and the change of centroid position on a fuel cell city bus, and then solves the suitable centroid position of this vehicle which makes the vehicle have satisfied steering characteristic.

Foundation's Grants for Electric Buses Ruled in Conformity With PF Tax Laws

A private foundation, created and solely funded by a utility providing electricity and natural gas services, is proposing to make grants to governmental bodies and other public charities to offset the cost difference between the purchase of gasoline and diesel vehicles and the purchase of electric vehicles. Prospective grantees are to include a governmental entity operating a city bus system and a public university. Essentially, the purpose of these grants is to subsidize the purchase of electric buses for the city.

The effects of autonomous buses to vehicle scheduling system

We are more and more close to the time when a higher number of autonomous vehicles are appearing in road traffic. The number of unanswered questions does not diminish but grow. One such issue is the role of autonomous vehicles in public transport. When talking about autonomous vehicles we often think of only cars and we think less about selfdriving buses. But the economic potential inherent in autonomous buses is huge. In the Hungarian vehicle and crew scheduling practice (and also in other countries) the one driver-one vehicle control is typical. This method closely links the vehicles and the drivers. Vehicles should therefore adapt to the rest time of the crew and the employment rules. Unused reserves are generated in the system. Autonomous vehicles can release this overcapacity. Thanks to that, fewer vehicles can carry out public transport tasks and we can save extra rides. It also provides a solution to the lack of drivers, which is a basic problem in many countries. In our study we show the reserves that can be recovered from the system in the case of three Hungarian cities (Eger, Dunaújváros, Győr). We show how much savings can be achieved by running autonomous buses in European cities with a population of 45 000, 54 000 and 130 000 inhabitants. The results are promising. In smaller cities we could achieve about 20% of economical savings but in bigger cities 40% is also realistic. Our statements are based on only rough calculations and they try to help in preparation for the future.

Emission Measurement of Buses Fueled with Biodiesel Blends during On-Road Testing

Increasing the biodiesel content of diesel fuels is encouraged because of its reduced carbon footprint. Pure rapeseed methyl ester (RME)and used cooking oil methyl ester (UCOME) are characterised by well-to-tank greenhouse gas (GHG) reductions of 54% and 88% compared to pure B0 petrodiesel, respectively. Captive fleets such as public transport buses could benefit from these GHG reductions by increasing the biodiesel content of their fuel because they have a consequent yearly fuel consumption. The aim of this paper is to compare on-road tailpipe emissions of a diesel bus when increasing the biodiesel concentration in the fuel. The tests were carried out on a standard city bus belonging to the Euro V EEV emission standard that was equipped with a portable emission measurement system measuring NO, NO2, PN, CO and CO2 at the tailpipe. The bus followed the SORT which is representative of urban bus driving. The heavy urban on-road measurements indicated increased NOx emissions (24–26%), decreased PN emissions (43–45%) and slightly decreasing CO emissions for B30 RME and UCOME compared to B7. A measurement uncertainty analysis showed that the CO emissions were less reliable. Similar conclusions were drawn for the easy urban on-road bus emission measurements with smaller differences between B7 and B30 RME and UCOME.

Seating Provision and Configuration of a 12m City Bus Considering Passenger Crowding

Seating capacity of a limited area significantly affects passenger crowding on a 12 m city bus, which is the main type of buses for public transport in China. This study aimed to provide an optimal solution for the seating capacity to adapt the passenger flow during operational periods. The study claimed that the seating capacity was defined by an overall crowding effect considering both the standees and seated passengers, whose demands for seat supply are different. It investigated the projected area of the seated passengers on board, defined the criteria regarding whether the current trip was a peak shift, and proposed a passenger crowding index for optimizing the seating capacity during two operational periods. It not only provided a recommended table between actual seating capacity and intensity coefficient varying along the two periods, but also discussed the number of 12 m buses with different seating capacities allocated to the bus line. It demonstrated the feasibility of the passenger crowding index through a case study and compared the effects of three main seat configurations existing on the 12 m city bus. It displayed that a seat capacity preferably ranged from 21 to 43 while only one seat configuration was allowed by the public transport enterprises.

Research on Optimization of Urban Electric Bus Timetable Based on Computer Technology for Energy-saving Objectives

Energy saving and environmental protection has always been a new innovation goal of various industries in China in the new era. At present, a lot of energy-saving and environmental protection concepts and related design have been put forward. The traditional city bus energy is gasoline[1]. In order to meet the requirements of energy conservation and environmental protection, the energy of city buses has been changed into electricity. The dispatching work of urban electric bus is the core of bus enterprise management and related operation. Under the goal of energy saving, the arrangement and optimization of urban electric bus timetable has become the main concern of urban public transport.

Психофізіологічні особливості роботи водіїв автобусів в містах

The aim of the article is to analyze the psychophysiological features of the work of drivers of urban passenger transport to take into account the human factor in the transport process. The performed analysis of researches of methods of rational organization of city bus transportations has defined the list of recommendations on planning of modes of work and rest of drivers of city buses. However, they do not take into account the intensity of the driver's work on the route. The driver's activity is one of the most intense and responsible types of work. It is associated with great nervous and emotional stress, requires constant stability and concentration, as well as quite high energy expenditure. Because of this, the issue of rationing and distribution of time in trucking companies is an important factor that is designed to actively influence the quality of the driver's work. It is established that such factors as fatigue, working conditions, physical environmental factors, biomechanical and physiological factors are important for ensuring the efficiency of the driver's activity. Thus, the rationalization of labor activity, creating the necessary prerequisites for maintaining the health and development of the employee's personality, will achieve a significant increase in efficiency and reliability of human activity. When organizing the work of city bus drivers, the psychophysiological features of their work are not taken into account at all. As a result, the role of the human factor in the transport process, regardless of the mode of transport, is even more important. As a result, there is a need to analyze the norms of the length of the working day established by the labor legislation, breaks during the working day for rest and meals.

A Comparative CFD Study of Side-view Mirror and Side-view Camera Usages on a City Bus

In this study, the effects of classical side mirrors and side-view cameras on the aerodynamic drag coefficient of a city bus model were investigated with Computational Fluid Dynamics (CFD). The surface profile of 1/5 scale bus was modeled with CATIA v5 program. Aerodynamic analyzes were per-formed with ANSYS Fluent® v18. Reynolds Average Navier-Stokes (RANS)-based Reynolds Stress Model (RSM) was used as the turbulence model. The ground effect was taken into consideration in all analyzes. The solution do-main for 5% blockage ratio was created. Inflation layers are used on the ve-hicle surface regarding velocity changes due to viscous effects. The mesh number independence of analyzes was examined for the bus model without side mirrors and provided for 1.3 M mesh element. The Reynolds number in-dependence of the analysis was investigated by using the optimum number of mesh. Free flow velocity of 90 m/s and above were found to be adequate for Reynolds number independence. The drag coefficient was calculated for the bus with side mirrors by using optimum mesh and wind speed as well. The drag coefficients for the bus with side mirrors and side view cameras were de-termined 0.53 and 0.521 respectively.

Association of presence and severity of obstructive Sleep Apnoea Syndrome with accident risk in city bus drivers.

To determine the relationship between frequency of traffic accidents and presence and severity of the disease in bus drivers who are at risk of having obstructive sleep apnoea syndrome (OSAS). In the present study, polysomnography (PSG) was applied on 162 city bus drivers directed to the sleep laboratory from a total of 1450 drivers after being determined as risky with regard to OSAS symptoms according to the questionnaire results. Their demographic characteristics, health status and accidents were compiled. Statistical analyses were made for those diagnosed with OSAS according to the PSG result and those with a traffic accident after which comparisons were made. Obstructive sleep syndrome was detected in 127 out of the 162 drivers determined to be risky with regard to OSAS based on the Berlin questionnaire result. While 50 (35%) of the drivers were normal according to the polysomnography (PSG) results in the study, 39 (24.1%) were determined as light OSAS, 35 (21.6%) as moderate OSAS and 53 (32.7%) as severe OSAS. While 105 (64.8%) of the cases had no accident, 37 (22.8%) were almost involved in an accident due to sleepiness and 20 (12.3%) were actually involved in an accident. A statistically significant relationship was determined between accident rates and OSAS severity (p:0.009; p<0.05). It was concluded that presence and increased severity of OSAS is an important risk factor for being almost or directly involved in an accident among city bus drivers, even though they were not driving for long distances.

JUSTIFICATION OF THE DEGREE OF NECESSITY OF QUALITY INDICATORS IN THE PASSENGER TRANSPORTATION EVALUATION SYSTEM

The approaches to assessing the quality of passenger transport services and indicators considered in scientific works, and also existing in state and international standards, are considered. A hierarchical system of indicators (ranking level) has been drawn up, which distributes the sequence of indicators of transport services. The foreign experience of organizing the work of municipal transport was taken into account, the quality of service of which is constantly monitored and as close as possible to the needs of passengers. However, a number of issues, namely: measuring the quality of transport services for the population on a digital scale, methods and methods for monitoring quality assessment, and improving it, etc., remain open. Based on the results of the preliminary study, the main indicators for assessing the quality of passenger transport were identified and grouped, both objective and dependent on the perception of the consumer, which most clearly describe the quality of the provision of passenger transport services. Almost all researchers in their works have determined that the system of general quality indicators should include the following indicators: availability, reliability, comfort, information content, safety, regularity, cost-effectiveness. But due to the importance of each of the elements of the complex indicator, it is necessary to take into account not only all the components of the quality assessment, but also, to a certain extent, their impact on the quality of the transportation process. The article analyzes the importance of each component included in the system of indicators for assessing the quality of transport services for passengers. The necessity of digital assessment of the quality of services for the transportation of passengers by city bus transport has been substantiated. The developed methodology will allow assessing the quality of passenger transportation by other types of transport. The degree of the need for quality indicators in the passenger traffic assessment system has been substantiated, which will allow evaluating the quality of passenger service not at the verbal level ("bad", "good"), but at the level of digital comparison. substantiation of the degree of need for quality indicators in the passenger traffic assessment system; considering the feasibility of each indicator with its constituent components, determining the degree of influence of each component on the quality of the provision of services for the carriage of passengers by road. For the digitalization of the assessment of the quality of transportation, the designation of the general quality indicator is adopted - Яобщ. In numerical terms, the quality indicator should tend to the maximum value, which in this study is taken as 4. For this, all indicators will be divided into separate components, the weight of which will be estimated at 0.1. A general indicator for assessing the quality of passenger transportation has been determined, which will determine the competitiveness of the enterprise, satisfy the need for a high-quality transportation process, taking into account all criteria and indicators. Thus, the assessment of the quality of passenger transportation, based on the minimum value of the coefficient, which will tend from 3.5 to 4, will determine the ability of the enterprise to carry out the transportation of passengers according to a qualitative assessment and, taking it into account, conduct tenders for the transportation of passengers. Keywords: quality assessment, indicators, transport service, transportation process, passenger traffic, monitoring, ranking.

Prediction of the Transition From Subexponential to the Exponential Transmission of SARS-CoV-2 in Chennai, India: Epidemic Nowcasting.

BackgroundSeveral countries adopted lockdown to slowdown the exponential transmission of the coronavirus disease (COVID-19) epidemic. Disease transmission models and the epidemic forecasts at the national level steer the policy to implement appropriate intervention strategies and budgeting. However, it is critical to design a data-driven reliable model for nowcasting for smaller populations, in particular metro cities.ObjectiveThe aim of this study is to analyze the transition of the epidemic from subexponential to exponential transmission in the Chennai metro zone and to analyze the probability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) secondary infections while availing the public transport systems in the city.MethodsA single geographical zone “Chennai-Metro-Merge” was constructed by combining Chennai District with three bordering districts. Subexponential and exponential models were developed to analyze and predict the progression of the COVID-19 epidemic. Probabilistic models were applied to assess the probability of secondary infections while availing public transport after the release of the lockdown.ResultsThe model predicted that transition from subexponential to exponential transmission occurs around the eighth week after the reporting of a cluster of cases. The probability of secondary infections with a single index case in an enclosure of the city bus, the suburban train general coach, and the ladies coach was found to be 0.192, 0.074, and 0.114, respectively.ConclusionsNowcasting at the early stage of the epidemic predicts the probable time point of the exponential transmission and alerts the public health system. After the lockdown release, public transportation will be the major source of SARS-CoV-2 transmission in metro cities, and appropriate strategies based on nowcasting are needed.

Real-Time Weather Monitoring and Prediction Using City Buses and Machine Learning.

Accurate weather data are important for planning our day-to-day activities. In order to monitor and predict weather information, a two-phase weather management system is proposed, which combines information processing, bus mobility, sensors, and deep learning technologies to provide real-time weather monitoring in buses and stations and achieve weather forecasts through predictive models. Based on the sensing measurements from buses, this work incorporates the strengths of local information processing and moving buses for increasing the measurement coverage and supplying new sensing data. In Phase I, given the weather sensing data, the long short-term memory (LSTM) model and the multilayer perceptron (MLP) model are trained and verified using the data of temperature, humidity, and air pressure of the test environment. In Phase II, the trained learning model is applied to predict the time series of weather information. In order to assess the system performance, we compare the predicted weather data with the actual sensing measurements from the Environment Protection Administration (EPA) and Central Weather Bureau (CWB) of Taichung observation station to evaluate the prediction accuracy. The results show that the proposed system has reliable performance at weather monitoring and a good forecast for one-day weather prediction via the trained models.

Impact on City Bus Transit Services of the COVID–19 Lockdown and Return to the New Normal: The Case of A Coruña (Spain)

The COVID–19 pandemic led to restrictions on activities and mobility in many parts of the world. After the main peak of the crisis, restrictions were gradually removed, returning to a new normal situation. This process has impacted urban mobility. The limited information on the new normal situation shows changes that can be permanent or reversible. The impact on the diverse urban transport modes varies. This study analyzes the changes in transit ridership by line, the use of stops, the main origin–destination flows, changes in transit supply, operation time, and reliability of the city bus network of A Coruña. It is based on data from automatic vehicle location, bus stop boarding, and smart card use. Data from the first half of 2020 were compared to similar data in 2017–2019, defining suitable baselines for each analysis to avoid seasonal and day of week effects. The impact on transit ridership during the lockdown process was more significant than that on general traffic. In the new normal situation, the general traffic and the shared bike system recovered a higher percentage of their previous use than the bus system. These impacts are not uniform across the bus network.

Examining the Heterogeneous Impact of Ride-Hailing Services on Public Transit Use

Practice or Policy Abstract

Online Web query system for various frequency distributions of bus passengers in Taichung city of Taiwan

It is highly desirable that traffic controllers or city residents can discern regular patterns and promptly detect irregularities or abnormal events in a public transportation system. This study proposes a web-based information system that allows users to study the travel behaviour of bus passengers from various perspectives. The system uses data from the comprehensive set of Taichung City Bus Riding Records between 2015 and 2016. However, it can provide the same functionality to any other similar bus transportation system by using the appropriate data. It should be emphasised that the system can provide the frequency distributions not only of passenger trips between two stops but also of the passenger volume for a given segment of any route. Owing to the increased computational and storage-capacity requirements of the proposed system, the scalable Hadoop MapReduce programming model was used. Furthermore, bus companies can use the system to design better service plans, such as more flexible bus schedules and more convenient routes, to meet passenger demand as well as reduce operation cost and energy consumption. The authors believe that the proposed system can make a valuable contribution to public welfare.

A Study on the Optimization of University School Bus Routes

통학버스는 학생의 등교를 원활하게 지원하기 위해서 복지 차원에서 운영되며, 대학의 지리적 입지에 따라 다양한 통학버스 운 영방식이 채택되어 운행되고 있다. 통학버스는 지정된 정차 지점을 방문하여 학생을 태우거나 내린 후 최종 목적지로 이동하는 형태로 운영되고, 운영 효율성을 높이기 위해서는 이동 시간과 비용을 절감해야 한다. 따라서 본 연구에서는 한 시간 이내로 통학 을 할 수 있는 통학 수요가 있는 K대학의 사례를 대상으로 통학버스 운영의 효율성을 극대화 할 수 있는 방안을 모색하고자 하였 다. 이를 위해 먼저 통학버스의 노선 현황을 파악하고 통학버스를 이용하는 학생들을 대상으로 설문조사를 하였다. 이를 통해 학 생들의 불편사항을 분석하고 통학버스의 운영 최적화를 위해 수리적 모델을 수립하고 최적해를 도출하고자 제약 프로그래밍 기법 을 적용하였다. 분석 결과는 다음과 같이 요약될 수 있다. 첫째, 통학버스 만족도를 분석하기 위해 설문조사를 시행하였고 학생들 은 통학버스의 등교 및 하교 시간대에 개선점이 필요하다고 생각하였다. 둘째, 통학버스 운행은 통학버스 투입 대수, 신청 학생, 학생들의 지리적 위치, 시간대별 이용 학생 수 등 다양한 불확실성을 내재하고 있다. 이러한 상황을 고려하여 본 연구에서는 통학 버스 운영방식을 등하교 노선을 같게 운영하도록 하여 단순화하는 방안을 제시하였다. 셋째, 통학버스가 시내버스와 같이 노선별 로 고정된 승차지점을 반복 운행하는 형태로 운영하게 되면 불특정 다수의 고객을 유입할 수 있는 이점을 제공할 수 있다. 따라서 본 연구의 분석 결과는 통학버스를 운영하는 대학의 입장에서 다양한 운영방식을 통해 학생의 편익과 대학의 재정적 손실을 최소 화는 방안을 해결하는 자료로 활용될 수 있는 측면에서 연구의 의의가 있다고 판단된다.School buses are operated in terms of transportation welfare in order to support commuting students, and depending on the geographical location of a university, a variety of school bus operating methods are adopted and operated. School buses are operated by visiting designated stops and picking up and dropping off students and moving to the final destination. Such operational efficiency can be achieved by saving travel time and money of students. Therefore, this study aimed to find a way to maximize the efficiency of school bus operation for the case of K-university where there is a demand of attending school by bus within an hour. To do this, the current route status of the school bus was first analyzed and a questionnaire survey was conducted for students who have had experience using the school bus. Through this, we analyzed the inconveniences of students and established a mathematical model to optimize the operation of the school bus and applied the constraint programming technique to derive the optimal solution. The analysis results can be summarized as follows. First, a questionnaire was conducted to analyze the satisfaction of the school bus, and students judged that improvement was necessary in operating time of the school bus. Second, the operation of the school bus implies a variety of uncertainties, such as the number of students entering the school bus, the number of students applying, the geographic location of students, and the number of students using each time zone. In consideration of such situation, this study suggested a way to simplify the way that the school bus operates by operating the same round-trip routes. Third, if the school bus operates the same round-trip routes such as a city bus, it can provide an advantage to attract an unspecified number of customers. Therefore, the analysis results of this study are considered to be meaningful in terms of providing an insight to solve students’ benefits and methods to minimize the financial loss of the university through various management methods from the viewpoint of the university.

Bisnis Transportasi dalam Pusaran Globalisasi

&lt;p&gt;&lt;em&gt;This study aims to examine the differences between conventional taxis and online taxis and whether the existing legal regulations are sufficient to regulate the two modes of transportation. The author's curiosity comes from seeing the past when taxis were considered a luxury means of transportation that people rarely use except for emergencies, so city buses and public transportation become the choice of citizens. The choice that was "forced" to be taken considering the low cost and far coverage. Now, when online taxis offer low costs and easy access, the means of transportation that have become "gods" have fallen. The drivers gasped, the transportation entrepreneurs were distracted to finance their business empire and the passengers were no longer greeted by buses and public transportation. This research is a sociological legal research which makes a phenomenon that exists in society and its influence on existing legal rules. The research results show that the difference between conventional taxis and online taxis lies in the amount of tariff, standardization of services, determination of routes and special features and legal protection. The government needs to be firm in regulating the existence of online transportation, given the potential for conflict over disparity in tariff differences and the importance of legal protection for drivers and passengers in driving safety.&lt;/em&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;&lt;em&gt;Keywords:&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;em&gt;&lt;em&gt;Online Taxi; Conventional Taxi; Legal.&lt;/em&gt;&lt;br /&gt;&lt;/em&gt;&lt;/p&gt;

Development Forecasts for the Zero-Emission Bus Fleet in Servicing Public Transport in Chosen EU Member Countries

Nearly two-thirds of the emissions that cause smog come from road transport. In April 2019, the European Parliament adopted new regulations on public procurement to encourage investment in clean buses—electric, hydrogen, or gas. Directive 2009/33/EC is to apply from the second half of 2021. The aim of this article is to make an attempt to simulate the number of zero-emission buses (ZEB) in European Union (EU) member countries in two time horizons: 2025 and 2030, and to forecast the number of clean vehicles in the precise time horizons, including before and after 2050. Research questions are as follows: (1) what will be the number of ZEBs in individual EU countries over the next few years; (2) which of the EU countries will reach by 2030 the level of 95% share of ZEBs in all buses, which are a fleet of public transport buses; and (3) in which year will which EU countries reach the level of 95% share of zero-emission buses. The method used is a Bass model. The conducted analyses demonstrate that, by 2050, only four of the EU members will be able to reach 95% level of share of clean buses in the city bus transport fleets. It is likely that other countries may not achieve this even by 2050.

CONCEPT ON LANDMARK DETECTION IN ROAD SCENE IMAGES TAKEN FROM A TOP-VIEW CAMERA SYSTEM

Abstract. In this paper, we demonstrate the inclusion of a top-view camera system mounted on a city bus in an existing sensor setup. A novel sensor setup with five down-facing cameras is mounted on the roof of a MAN Lion’s City 12 city bus to extract landmarks in road scene images. Its positioning is validated by an exemplary detection of lane markings. The concept for further landmark detection with the help of the presented camera system is explained in this paper and sensor data fusion methods are proposed. Based on our previous findings (Albrecht et al., 2019), strengths of the novel sensor system are introduced to improve the current environment perception system. For now, only a qualitative observation of the capability to detect lane markings and other landmarks can be presented. Future work will use the current findings for landmark detection for a vehicle self-localization system.