Modal shift implications of e-bike use in the Netherlands: Moving towards sustainability?

This paper investigates the modal shift patterns of e-bike users in the Dutch context. We focus on the change in e-bikers’ travel behavior to assess whether this change benefits sustainability. Our study provides direct ecologically valid evidence on modal shift by using a longitudinal dataset from the Netherlands Mobility Panel survey. We examine e-bikers’ modal shift patterns before and after acquiring an e-bike. The findings indicate that after e-bike adoptions, conventional bike use reduces significantly, while car use reduces less strongly. Nonetheless, the share of car kilometers is much larger than that of conventional bikes at the baseline. Besides, the emission rate per passenger kilometer of an e-bike is several times lower than that of a car. These imply a net environmental gain after e-bike adoptions. The present study also sheds light on modal shifts at a disaggregated level by investigating those e-bikers who are more likely to drive less after e-bike adoption. The findings suggest that e-bikers younger than 50 and those around retirement age (60–69) seem more likely to step out of their cars. Additionally, people living in rural areas tend to be more likely to reduce their car use than their counterparts in highly urbanized areas. Based on our findings, we present policy recommendations for achieving a greener shift in mobility systems.     

Effects of e-bikes on bicycle use and mode share

In Norway, as in many countries, a political goal is to increase bicycle use, and the e-bike is promising in this respect. However, concerns have been raised about mode-share effects. It has been argued that if the e-bike’s only function is in cycling becoming cycling with electric assistance, there would be no benefit to either the environment or public health. Little is yet known about the use of the e-bike, or of its potential in reducing motorized travel. In the current study, 66 randomly selected participants were given an e-bike to use for a limited period of time and the results compared with those of a control group (N = 160). E-bike cycling trips increased from 0.9 to 1.4 per day, distance from 4.8 km to 10.3 km and, as a share of all transport, from 28% to 48%, whereas with the control group there was no increase in cycling. The effect of the e-bike increased with time, indicating a learning effect among users, and was greater for female than for male cyclists. There were no differences with age. Overall, the results suggest that the e-bike is indeed practical for everyday travel.     

Effect of environmental awareness on electric bicycle users’ mode choices

Travellers’ environmental awareness can affect their mode choices. The primary objective of this study is to identify the effect of electric bicycle (e-bike) users’ environmental awareness on their mode choice when the use of e-bikes is prohibited in urban areas in China. The data were collected via a questionnaire survey administered at ten locations in Nanjing, China. Using mixed multinomial logit (MMNL) models, we examined the relationship between the e-bike users’ mode choice and their environmental awareness, combined with socioeconomic and demographic characteristics and trip attributes. The results show that the level of environmental awareness, gender, age, education, income, the ownership of car and conventional bike, and trip distance affect e-bike users’ choices significantly. Those with a high level of environmental awareness are more likely to choose zero-emission transport modes. A stratified analysis reveals that the effect of environmental awareness is associated with their original transport mode choice prior to their use of the e-bike. With a high level of environmental awareness, original car users tend to opt for moderate- or zero-emission modes; original bus and metro users incline to choose a zero-emission mode or their original mode; and few original cyclists and walkers favour moderate- or high-emission modes. The results of the current study provide transport authorities with insights to establish sustainable urban transportation management policies and strategies to increase the share of zero- and low-emission transport modes.     

Factors influencing the choice of shared bicycles and shared electric bikes in Beijing

China leads the world in both public bikeshare and private electric bike (e-bike) growth. Current trajectories indicate the viability of deploying large-scale shared e-bike (e-bikeshare) systems in China. We employ a stated preference survey and multinomial logit to model the factors influencing the choice to switch from an existing transportation mode to bikeshare or e-bikeshare in Beijing. Demand is influenced by distinct sets of factors: the bikeshare choice is most sensitive to measures of effort and comfort while the e-bikeshare choice is more sensitive to user heterogeneities. Bikeshare demand is strongly negatively impacted by trip distance, temperature, precipitation, and poor air quality. User demographics however do not factor strongly on the bikeshare choice, indicating the mode will draw users from across the social spectrum. The e-bikeshare choice is much more tolerant of trip distance, high temperatures and poor air quality, though precipitation is also a highly negative factor. User demographics do play a significant role in e-bikeshare demand. Analysis of impact to the existing transportation system finds that both bikeshare and e-bikeshare will tend to draw users away from the “unsheltered modes”, walk, bike, and e-bike. Although it is unclear if shared bikes are an attractive “first-and-last-mile solution”, it is clear that e-bikeshare is attractive as a bus replacement.     

Why early adopters engage in interpersonal diffusion of technological innovations: An empirical study on electric bicycles and electric scooters

Early adopters promoting electric vehicles in their social network may speed up market uptake of this technology. Apart from their opinion leader status, few previous research details the motivations which turn early adopters into advocates for innovation who approach the non-adopters among their family and friends, or casual acquaintances.Drawing on a survey among 1398 e-bike and 133 e-scooter early adopters in Austria, personal drivers of engagement in interpersonal diffusion are investigated. Longitudinal data one year later for 157 e-bike users allows tests of causal relations. A complementary sample of 33 network peers illustrates the early adopters’ social impact.Early adopters engage actively in discussing product features, instigating trial behavior and recommending purchase. Analyses by structural equation modeling show that efforts at interpersonal diffusion are driven by opinion leadership, experienced product performance, and perceived normative expectations of others toward pro-environmental technologies. Mediator and moderator analyses underline that opinion leadership is conveyed upon early adopters because personal norms and technophilia qualify them as credible and competent for the specific topic of e-vehicles. Social norm interrelations point to dynamic interactions and discourse between early adopters and their addressees. Evidence from the peer sample suggests though that the persuasive impact of early adopters is small.To accelerate market entry of electric vehicles, public or private agencies should foremost approach early adopters scoring high in the identified drivers, and empower them in their role as multiplicators by providing pre-prepared product information and encouraging them to continuously address peers.     

From e-bike to car: A study on factors influencing motorization of e-bike users across China

Household car ownership has risen dramatically in China over the past decade. At the same time a disruptive transportation technology emerged, the electric bike (e-bike). Most studies investigating motorization in China focus on macro-level economic indicators like GDP, with few focusing on household, city-level, environmental, or geographic indicators, and none in the context of high e-bike ownership. This study examines household vehicle purchase decisions across 59 cities in China with broad geographic, environmental, and socio-economic characteristics. We focus on a subset of households who own e-bikes and rely on a telephone survey from an industry customer database. From these responses, we estimate two three-level hierarchical choice models to assess attributes that contribute to (1) recent car purchases and (2) the intention to buy a car in the near future. The results show that the models are dominated by household characteristics including household income, household size, household vehicle ownership, number of licensed drivers and duration of car ownership. Some geographic, environmental and socio-economic factors have significant influences on car purchase decisions. Only two city-level transportation variable have an effect – higher taxi density and higher bus density reducing car purchase. Cold weather, population density gross domestic product per capita positively influence car purchase, while urbanization rate reduces car purchase. Because of supply heterogeneity in the data set, described by publicly available urban transportation data, this is the first study that can include geographic and urban infrastructure differences that influence purchase choice and suggests potential region-specific policy approaches to managing car purchase may be necessary.     

Travel mode choices in small cities of China: A case study of Changting

The existing literature on urban transportation planning in China focuses primarily on large cities and neglects small cities. This paper aims to fill part of the knowledge gap by examining travel mode choice in Changting, a small city that has been experiencing fast spatial expansion and growing transportation problems. Using survey data collected from 1470 respondents on weekdays and weekends, the study investigates the relationship between mode choice and individuals’ socio-economic characteristics, trip characteristics, attitudes, and home and workplace built environments. While more than 35 percent of survey respondents are car owners, walk, bicycle, e-bike, and motorcycle still account for over 85 percent of trips made during peak hours. E-bike and motorcycle are the dominant means of travel on weekdays, but many people shift to walking and cycling on weekends, making non-motorized and semi-motorized travel especially important for non-commuting trips. Results of multinomial logistic regression show that: (1) job-housing balance might exert different effects on mode choice in different types of urban areas; (2) negative attitude towards e-bike and motorcycle is associated with more walking and cycling; and (3) land use diversity of workplace is related to commuting mode choice on weekdays, while land use diversities of both residential and activity places do not significantly affect mode choice on weekends. Our findings imply that planning and design for small cities needs to differentiate land use and transportation strategies in various types of areas, and to launch outreach programs to shift people’s mode choice from motorized travel to walking and cycling.     

The transition to electric bikes in China: history and key reasons for rapid growth

Annual electric bike (e-bike) sales in China grew from 40,000 in 1998 to 10 million in 2005. This rapid transition from human-powered bicycles, buses and gasoline-powered scooters to an all-electric vehicle/fuel technology system is special in the evolution of transportation technology and, thus far, unique to China. We examine how and why e-bikes developed so quickly in China with particular focus on the key technical, economic, and political factors involved. This case study provides important insights to policy makers in China and abroad on how timely regulatory policy can change the purchase choice of millions and create a new mode of transportation. These lessons are especially important to China as it embarks on a large-scale transition to personal vehicles, but also to other countries seeking more sustainable forms of transportation.

隧道粉尘颗粒物的危害及控制措施分析

目前我国隧道大规模快速的发展,而钻爆法以其高效、经济的特点在隧道建设过程中起着至关重要的作用。然而,施工期隧道钻孔、爆破、喷射混凝土、出渣等施工工艺都会扬起大量粉尘颗粒物,严重危害现场人员的身体健康,降低施工现场的能见度影响施工效率和安全,同时大量颗粒物加剧机械设备磨损,在一定程度上影响了设备的使用寿命。结合隧道开挖过程,根据粉尘在隧道内分布规律,粉尘产生因素及运移机理,通过比较隧道减尘、降尘、排尘、除尘、阻尘五种控制措施的特点,提出与现场相适应的粉尘颗粒物综合防治措施,从而减小粉尘的危害,提高现场施工环境质量。     

基于LEAP模型的城市客运交通能耗和污染物排放预测

我国交通运输业能源消耗量与污染物排放量日益增多,交通部门的节能减排措施研究迫在眉睫。本论文基于LEAP模型构建了某城市客运交通能耗与污染物排放模型,并预测了基准情景、政策情景、技术情景及综合情景下该城市客运交通2014-2030年之间的能耗及污染物排放情况。研究表明,三种发展情景下该城市能源需求量及污染物排放较基准情景均有减少,其中综合情景效果最佳,综合情景在2030年的能源消耗与CO2排放可分别减少56.98%和54.55%,CO、HC、NOx与PM2.5可分别减排67.39%、67.27%、51.43%与75.38%。因此应大力发展公共交通,尤其是轨道交通,同时限制私家车的无节制发展,并推广节能环保技术以改善终端利用层次能源结构。     

The contribution of road traffic to particulate matter and metals in air pollution in the vicinity of an urban road

A detailed investigation was conducted to study the sources of particulate matter in the vicinity of an urban road in Žilina. To determine the amount of particulate matter (PM₁₀, PM_2.5 and PM₁) present in the ambient air, a reference gravimetric method was used. The main objective of this contribution was to identify the sources of these particles by means of statistical methods, specifically principal component analysis (PCA), factor analysis (FA), and absolute principal component scores (APCS), as well as using the presence of 17 metals in the particulate matter (Na, Mg, Al, Ca, V, Cr, Fe, Mn, Ni, Cu, Zn, As, Mo, Sb, Cd, Ba, Pb). To identify the metals in the particulate matter samples and to determine their abundances, spectroscopic methods were used, specifically inductively coupled plasma mass spectrometry (ICP-MS). Each of these metals may come from a specific source, such as the burning of fossil fuels in fossil fuel power plants; local heating of households; the burning of liquefied fossil fuels in the combustion engines of vehicles; the burning of coal and wood; non-combustion related emissions resulting from vehicular traffic; resuspension of traffic-related dust; and industry. Diesel vehicles and non-combustion emissions from road traffic have been identified as two key sources of the particulate matter. The results reveal that non-combustion emissions, which are associated with the elements Na, Fe, Mn, Ni, Zn, Mo, Sb, Cd, and Pb, are the major contributors, followed by combustion emissions from diesel vehicles, which are associated with the elements Mg, Ca, and Ba.     

海底管道单项高风险因素分析

为了准确掌握海底管道在运行阶段面临的各种单项高风险因素,通过采用相应模型计算和OLGA模拟等方法,以某管道为例,得到了对管道安全影响较大的单项高风险因素为海底管道埋深、海床变化、析蜡可能性、水合物堵塞可能性、结垢、沥青质沉积、抛锚与拖网干扰等、腐蚀、悬跨影响等。文中给出了相应的风险减缓措施,为解决生产实践中海底管道存在的安全隐患提供了依据,预防海底管道事故的发生。     

三阶段检查台账在公路建设质量监督管理中的应用

高速公路的建设需要良好的质量控制措施,质量专项检查就是进行质量监督、管理、控制的重要和有效手段。在实践中按其进度和重要性,我们把它分成三个关键阶段:第一个关键阶段路基、结构物下部;第二个关键阶段路面底基层、基层、结构物上部;第三个关键阶段路面面层、交通安全设施。我们对三个关键阶段完成后所进行的质量专项检查简称三阶段检查,以此实现消除工程隐患,提高质量的目的。     

沿海九省港航发展情况定位分析

通过对沿海辽宁、河北、山东、江苏、浙江、福建、广东、广西和海南等九省2001、2006和2007三年揭示港航发展状态数据的灰色聚类分析,得出了广东的港航发展一直位居第一,浙江已经跃居第二,江苏第三,山东始终排在第四和辽宁正在逐步攀升等重要结论。其结论和揭示的内涵对山东和沿海各省的港航在落实科学发展观、推动现代化发展等方面具有参考价值。     

基于AHP-DEMATEL的高铁枢纽换乘效率关键因素研究

为了找出影响高铁枢纽换乘效率关键因素,科学合理高铁枢纽布局,提出一种基于AHPDEMATEL组合评价方法。以高铁枢纽为评价对象,通过构建具有层次结构的评价指标体系,采用层次分析法(AHP)确定指标初始权重,决策与试验评价实验室法(DEMATEL)求得各评价指标影响度、被影响度、中心度,从而确定各指标综合影响度。研究结果表明:其他交通衔接性、通道便捷性、设施供给度、枢纽组织有序度、停车场供需比、平均换乘时间、平均换乘距离、单位时间换乘量、绕行系数是影响高铁枢纽换乘效率的关键因素。     

影响含有凹痕管道运行寿命的因素研究

国外管道设计标准普遍采用凹痕深度对管道凹痕是否需要修复进行评估，但是，很多满足标准中凹痕深度要求的凹痕仍会发生失效。因此，国外许多研究机构对含有凹痕的管道进行了大量的试验研究。通过比较现场和试验数据，并使用计算软件对管道的压力进行分析，试图从各个方面找出影响含有凹痕的管道运行寿命的因素。文中对此进行了总结，介绍了凹痕长度、凹痕深度、凹痕肩部坡度、凹痕尖度、管道几何形状、管道材料、运行压力、焊缝、壁厚变薄对管道上凹痕疲劳行为的影响。最后得出了结论．并提出建议。     

沥青混凝土路面平整度差的成因及对策研究

结合G205、G312等沥青路面不同程度出现的沉陷、接缝台阶、波浪、车辙、桥涵与路面接茬不平、跳车等路面不平整现象,分析、探讨造成沥青路面平整度差的路基、桥涵、路面基层施工方面、材料方面以及路面摊铺、碾压等主要原因,并提出相应对策措施。     

The Concept and Practice of Treatment for Damage in Railway Tunnel Linings Caused by High-pressure Karst Water北大核心CSCD

In recent years, railway tunnels in karst areas have frequently suffered flooding after high-intensity rainfall, which seriously affects the safety of tunnel operation and the order of transportation, and even interrupts the traffic. Based on the water hazard case in the Yuanbaoshan Tunnel on the Zhijin-Bijie Railway Line, this paper explores the causes of lining damage in terms of geology, rainfall, and the design and construction of water hazard sections, and puts forward the treatment technology for tunnel water hazards with the core concept of "making full use of existing structures and employing open drainage methods in key sections". Besides, this paper simulates and analyzes the formation of hazards and the treatment effect through numerical simulation. The results show that the subjective causes for the damage in tunnel linings include an insufficient understanding of the water-bearing formations at the geological investigation stage, the underestimation of water hazard risks posed by high-intensity rainfall during construction, and the unimproved waterproof and drainage system in the design alteration, while the objective reasons include the development of karst near the tunnel section that passes through the stratum, the strong connectivity of water conduits, and the high-intensity rainfall in a certain period of time on the tunnel site. As for the simulation results, they show that the increase of external water pressure caused by the sudden rise in groundwater level after rainstorm significantly increases the internal force of linings, and eventually leads to a much lower safety factor of sidewall linings and large scale damage, which is in consistency with the characteristics of the actual on-site damage. After on-site emergency treatment, the tunnel structure has become stable and even encountering unprecedentedly heavy rainfall twice, the tunnel has still remained in a good condition. Since then, no water hazards and other disasters have occurred, which proves that the treatment plan is valid. © 2022, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

德国柏林职业教育模式的启示

文章从德国柏林政府、企业、学校、行会在职业教育中的关系、地位、职责和作用入手,介绍了德国柏林职业教育运行的体制机制情况,并针对我国国情与职业教育现状,提出了加强和改进我国职业教育工作的措施建议。     

探地雷达技术在隧道围岩深层病害检测中的应用

探地雷达作为一种先进而实用的无损检测技术，在许多工程领域得到了广泛应用。文章根据探地雷达的工作原理，提出将探地雷达应用于隧道围岩深层病害的检测。检测结果表明，在围岩深层病害检测中，采用探地雷达技术能够准确确定围岩深层病害的特征及其分布情况，克服了常规检测方法的局限性，并具有无损、直观、快速、高精度等特点。