An analysis of soft transport policy measures implemented in Sweden to reduce private car use

Evaluations carried out in many countries show that soft policy measures in the form of personalized travel planning reduce private car use and increase travel by public transport. Sweden is a sparsely populated country that poorly supports public transport, a country with long distances, a cold climate, and a high concentration of private cars, which is why soft policy measures implemented in Sweden may be less cost-effective than has been found in other countries. Thirty-two programs using personalized travel planning were analysed with regard to stewardship, geographic area of application, choice of techniques of exerting an influence, and effects on car use and choice of alternative travel modes. None of the evaluations of the documented programs met the method requirements for such evaluations as regards design and effect measurement. Additionally, reporting was substandard as well as non-standard in the way that is desirable in order to enable comparative analyses. With reservations for these shortcomings, it is inferred that positive effects on a par with the results in other countries have been obtained in some of the implemented programs. It is however necessary to conduct evaluations which are of higher quality. The requirements which will then have to be applied are defined.     

有氧生活

跳上SUV穿上球鞋踩碎无力，来一段有氧节奏……[编者按]     

Open boundary conditions in stratified ocean models

In most applications of numerical ocean models, artificial boundaries are introduced to limit the domain. Along such a boundary we need to apply what is often referred to as an open boundary condition (OBC). In this paper a number of local methods used in barotropic ocean models are applied and discussed for the stratified case using a normal mode approach. The OBCs are the simple conditions: clamped, prescribed and zero gradient; the radiation conditions: Camerlengo–O'Brien, Orlanski and a method of characteristics based on linear equations; and a sponge type condition: the flow relaxation scheme. The OBCs have been implemented in a 3-layer ocean model and examples of how the various OBCs perform for three simple flow situations are investigated. The cases are: internal wave radiation, a quasi-steady coastal jet and the response to a storm moving across a strait. It is found that the flow relaxation scheme and the method based on characteristics perform well for the test cases in general, although some of the simpler methods give better results in individual cases.     

新消费税的“紧箍咒”与“痒痒挠”

回首2006年国内首次改变汽车消费税率，做出扬小抑大的姿态，但还是出现了保时捷、宝马大排量瓣年超过50%的市场增长。与此形成对应的，是近两年1．6L轿车在汽车厂家概念行销的阴谋下，莫名其妙地成为了家用轿车黄金排量．1．0L以下的小排量车也随之出现了销售低谷。而有行业专家表示，单从消费税角度入手，即使完全取消了小排量的消费税，也不过在减少百元左右，并不能形成明显的价格杠杆作用，因此，在深度剖析“紧箍咒”和“痒痒挠”的问题时，很多消费税之外的因素和博弈不得不考虑。     

Rules for aggregated satisfaction with work commutes

In general trips frequently entail several stages varying in mode, duration, and other factors. In some way travelers aggregate their satisfaction with the stages to satisfaction with the whole trip. In this paper we address the question of how this aggregation is made. We use data from a Swedish survey measuring satisfaction with commutes to and from work and with the stages of the commutes. We test several aggregation rules for their goodness of fit to the observations. Our results show that a normatively correct averaging rule that takes into account the relative durations of the stages out-perform heuristic aggregation rules such as the peak-end, summation, and equal-weight averaging rules. We note that this does not exclude that the heuristic aggregation rules apply to other trips than repetitive commute trips.     

Subjective well-being related to satisfaction with daily travel

Previous research demonstrates an impact on subjective well-being (SWB) of affect associated with routine performance of out-of-home activities. A primary aim of the present study is to investigate whether satisfaction with daily travel has a positive impact on SWB, either directly or indirectly through facilitating the performance of out-of-home activities. A secondary aim is to determine whether emotional-symbolic or instrumental reasons for car use results in higher satisfaction with daily travel than other travel modes. A survey of a population-based sample of 1,330 Swedish citizens included measures of car access and use, satisfaction with daily travel, satisfaction with performance of out-of-home routine activities, and affective and cognitive SWB. The results confirmed that the effect on affective and cognitive SWB of satisfaction with daily travel is both direct and indirect via satisfaction with performance of activities. Percent weekly car use had a small effect on satisfaction with daily travel and on affective SWB, although fully mediating the effect of satisfaction with performance of the activities. This suggests that car use plays a minor role for satisfaction with daily travel and its effect on SWB. This role may be larger if investigated after a forced reduced car use.     

Author Index Volume 30 2003

Authors Index

Author Index Volume 30 2003     

Children’s travel to school: satisfaction,current mood,and cognitive performance

We investigate whether travel mode, travel time, and activities during travel influence children’s satisfaction with their travel to school, their current mood, and their cognitive performance after arriving at school. A sample of 344 children (165 girls) between the ages of 10 and 15 years were recruited at five public schools in Värmland County, Sweden. Directly after arriving at school, the children rated how they felt on two scales ranging from very sad to very happy and from very tired to very alert, filled out the Satisfaction with Travel Scale adapted for children (STS-C), reported details about their journeys, and took a word-fluency test. The results for STS-C showed that traveling by school bus and walking or cycling was experienced as having a higher quality than traveling by car. Children who engaged in conversation during their journeys reported a higher quality and more positive feelings than children who were engaged in solitary activities during their journeys. A shorter journey was experienced as having a higher quality and resulting in more positive feelings. Children traveling for longer durations performed better in the word-fluency test if using their smartphones or doing a combination of activities during their journeys.     

具初始裂纹钢桥梁焊接构件疲劳裂纹扩展和疲劳寿命计算

钢桥梁构件因焊接缺陷或者在疲劳应力交互作用下萌生裂纹,钢桥梁构件因存在初始裂纹大大地降低焊接构件的疲劳性能.文中考虑到焊接构件往往会存在初始缺陷,研究了含初始缺陷的桥梁焊接构件的疲劳分析方法.在已有的大量含裂纹构件的疲劳实验工作基础上,结合课题组所做的焊接构件疲劳实验资料,假设初始裂纹焊接构件在疲劳裂纹扩展过程中裂纹形状保持为半椭圆形状;针对桥梁构件实际受力特征,由钢桥梁构件的高周疲劳损伤演化方程入手,考虑初始裂纹条件下裂纹前缘的损伤区的存在及其对裂纹扩展的影响,采用虚拟裂纹扩张方法推导了适用于钢桥梁构件的疲劳裂纹扩展分析的疲劳裂纹扩展率公式,建议了裂纹扩展和疲劳寿命数值计算方法.采用文中的计算方法,研究了已有的钢桥梁结构焊接构件疲劳实验的裂纹扩展过程和疲劳寿命的计算.计算结果表明:裂纹的扩展过程中裂纹的深度和表面半长度之比a/c是一个变化的数值,且在一定的a0/t0条件下,随着a0/c0的增加,循环次数逐渐增大.     

新Z4的快乐印迹

宝马艺术车曾经把波普、把印地安部落图腾、把日本烫箔艺术展示给我们,而这次宝马展示的是它自己。