浅议地铁施工对北京市环境的影响

北京地铁四号、五号、十号线及奥运支线总长近100km的地铁线路均要求在2008年前建成通车,多条地铁线路同期施工必然会对城市环境和居民生活等造成较大的影响.文章根据地铁工程的施工特点,对此进行了初步分析探讨,并提出了有关应对措施的建议.     

The effects of highway development on housing prices

The purpose of this research is to estimate the effects of highway development projects on the price of housing. Transportation development projects, highways in particular, improve a certain area’s accessibility but also increase its levels of exposure to traffic intensity and noise pollution. These externalities are evaluated by homeowners and residents and are reflected in the price of housing. In this paper, we use several repeat sales model specifications, including difference-in-differences estimators, and control for neighborhood effects to examine housing price trends in the municipalities around two newly developed highways in the Netherlands. The results of the research demonstrate that changes in accessibility result in a significant positive effect on the price of housing in nearby municipalities, but that increased noise pollution and traffic intensity levels result in a decrease in prices. The findings also confirm that combining the total effects of all externalities, the effect of highway development on the price of housing is generally positive, and this effect is salient even before the project is completed due to public anticipation effects.     

Transportation infrastructure improvement and real estate value: impact of level crossing removal project on housing prices

This paper studies the impact of removing the level crossing, which constitutes traffic hazard to the society, on house prices by conducting a quasi-natural experiment using the Level Crossing Removal Project (LXRP) implemented by the Victoria state government in Australia since 2015. Using a difference-in-differences method, we analyzed the changes in housing prices due to the improvement of transportation infrastructure, gauging the LXRP’s impact on house and unit submarkets separately. We found that the prices for house and unit markets increased significantly after the removal of level crossings, with the value uplift decreasing with distance from the removal site. This paper contributes to the existing literature by adding an empirical study related to the enhancement of infrastructure aiming to improve the traffic safety in the urban context. Unlike previous studies, this study examines the effect of improvement projects for existing infrastructure and provides relevant implications to improve the efficiency of investing public resources in infrastructure improvement.

     

The impact of rail access on condominium prices in Hamburg

Using hedonic price functions, we study the influence of access to public railway stations on the prices of surrounding condominiums in Hamburg, Germany. The study examines the influence of rail infrastructure on residential property prices, not only of individual lines, but for the entire rail network of a metropolitan region. We test the stability of the coefficients for different sets of control variables. The study also estimates public-transit-induced increases in tax revenues due to real estate price increases for a study area outside the United States. We control for spatial dependence and numerous variables correlated with the proximity of railway stations and show that access to the public transit system of the city of Hamburg is to be rated with price increases of up to 4.6%. Such premiums for higher-income neighbourhoods and for subterranean stations tend to be higher. The premiums calculated are significantly lower than average price premiums reported in previous studies, which were mostly based on much fewer variables that rail access might be correlated to.     

The impact of a financial constraint on the spatial structure of public transport services

Using a single line model, it has been shown recently that the presence of a stringent financial constraint induces a less than optimal bus frequency and larger than optimal bus size. This occurs because the constraint induces a reduction of the importance of users’ costs (their time); in the extreme, users’ costs disappear from the design problem. In this paper we show that such a constraint also has an impact on the spatial structure of transit lines. This is done departing from the single line model using an illustrative urban network that could be served either with direct services (no transfers) or with corridors (transfers are needed). First, the optimal structure of lines is investigated along with frequencies and vehicle sizes when the full costs for users and operators are minimized (unconstrained case); the optimal lines structure is shown to depend upon the patronage level, the values of time and the cost of providing bus capacity. Then the same problem is solved for the extreme case of a stringent financial constraint, in which case users’ costs have relatively little or no effect in determining the solution; in this case the preferred outcome would be direct services under all circumstances, with lower frequencies and larger bus sizes. The impact of the financial constraint on the spatial structure of transit lines is shown to be caused by the reduction in cycle time under direct services; the introduction of users’ costs in the objective function makes waiting times reverse this result under some circumstances.     

北京地铁五号线预制盾构管片的高性能混凝土研究

文章通过利用2次正交试验,对内掺4种掺合料的高性能混凝土配合比的多指标进行了评价和筛选,确定了理论配合比.与国内其他地铁管片厂家的混凝土配合比相比,该配合比的突出特点是总胶凝材料用量较低、大量使用了矿碴掺合料、水胶比和砂率较低.依据该配合比配制的混凝土试验结果表明混凝土强度达到了C50、拌合物易于浇捣、28天收缩值较纯水泥降低一半、抗渗等级为P30、碱含量仅2.4 kg/m3,满足用于潮湿条件等耐久性要求.目前用该配合比生产的预制盾构管片已在北京地铁五号线中累计使用超过1 000环,满足工程无结构缺陷、无外形缺陷、无外表缺陷和无外表油污的四无质量要求.     

Measuring unobserved prices using the structural time-series model: The case of cycling

This study presents a means of determining a historic (generalised cost based) price index for cycling in the UK for the period 1949–2006 using annual demand data. By specifying demand as a function of generalised price and income and then applying a structural time-series model to elucidate the unobserved component of prices (while controlling for observed income levels), it is illustrated that the role of prices in influencing demand is non-trivial. Over the sample period price responses generally influence demand for cycling to a greater extent than income effects.     

Urban transportation and equity: A case study of Beijing and Karachi

Development of mega cities of Pakistan and China has greatly been affected by the growth in urbanization and motorization. The uncontrolled rise in urbanization, motorization, exclusionary planning and disproportionate investment in transportation infrastructure has created a socio-economic imbalance, thereby challenging the issue of equity. This paper focuses on a comparative social equity assessment of urban development, characteristics of supply and demand of transportation and infrastructure systems and the impact of existing strategies over equity in the development of urban and transportation system of Beijing and Karachi. The paper concludes by suggesting some strategies for the development of sustainable and equitable urban transportation systems.     

Delivering trusting partnerships for route bus services: A Melbourne case study

The Thredbo Conference series has developed the idea of negotiated performance-based contracts as effective public transport service delivery mechanisms, with trusting partnerships between authority and operators providing an environment likely to maximise the performance of this delivery mode. However, there is a distinct lack of relevant case study material on trusting partnerships in public transport to affirm this proposition. This paper seeks to redress the balance. It outlines the system development directions that are being implemented for bus services in Melbourne, Australia, and the way that a broad-based constituency has been built to support those directions. It then illustrates the extension of the tactical trusting partnership approach between purchaser and provider to the level of the individual operator contract, showing how this should create a flexible yet disciplined environment to manage and cope with change and growth. The broad nature of the new contracts is summarised and, building on the findings from Thredbo 9, processes that are being implemented to manage the on-going relationship between purchaser and providers are outlined. Finally, the paper argues for extending KPIs beyond the operator to encompass the authority/regulator and the partnership of authority/operator, to extend performance pressures beyond the operator and recognise the interdependence of partners in a true partnership.     

Assessing the impact of the built environment on travel behavior: a case study of Buffalo,New York

Assessing the impact of characteristics of the built environment on travel behavior can yield valuable tools for land use and transportation planning. Of particular interest are planning models that can estimate the effects of ‘smart growth’ planning. In this paper, a post-processor method of quantifying and searching for relationships among many aspects of travel behavior and the built environment is developed and applied to the Buffalo, NY area. A wide scope of travel behavior is examined, and over 50 variables, many of which are based on high-detail data sources, are examined for potentially quantifying the built environment. Linear modeling is then used to relate travel behavior and the built environment, and the resulting models may be applied in a post-processor fashion to travel models to provide some measure of sensitivity to built environment modifications. The study’s findings demonstrate that mode choice is highly correlated to measures of the built environment, and that many of the principles of smart growth appear to be a valid way to encourage non-vehicle travel. Home-based VHT and VMT appear to be affected by the built environment to a lesser degree.     

北京地铁四号线区间工法的选择

文章简要论述了地铁区间施工方法的特点及适用条件,并结合北京地铁四号线的工程实践,分析了盾构法在地铁区间施工中的控制和影响因素.     

The relationship between property values and railroad proximity: a study based on hedonic prices and real estate brokers' appraisals

We study the relationship between the price of residential property value and proximity to railroads in Oslo, by two different methods, namely a) through a hedonic price study where the statistical relationship between property prices and railroad proximity is estimated, and b) through a multi-attribute utility investigation of real estate agents' evaluation of such a relationship. We find in both cases that there are strong effects of proximity to railroad lines on property prices, at distances less than 100 meters from the lines. In the statistical study log-linear relationships fit the data best, and our estimates indicate that a doubling of the distance from the railroad line, within a 100 meter bound, increases the property price by about 10%. With real estate agents only a linear relationship is probed. This yields an increase in the price of an average relevant housing unit by about 182,000 NOK, due to a increase in the distance to a railroad track from 20 to 100 meters. The equivalent figure from the statistical study is in the range 120–150,000 NOK. The two figures are thus of the same magnitude.     

Understanding urban mobility patterns from a spatiotemporal perspective: daily ridership profiles of metro stations

Transportation - Smart card data derived from automatic fare collection (AFC) systems of public transit enable us to study resident movement from a macro perspective. The rhythms of traffic...     

The impact of car specifications,prices and incentives for battery electric vehicles in Norway: Choices of heterogeneous consumers

Electric vehicles (EVs), specifically Battery EVs (BEVs), can offer significant energy and emission savings over internal combustion engine vehicles. Norway has a long history of research and government incentives for BEVs. The BEV market in Norway allows us to fully examine consumers’ BEV choices influenced by car specifications, prices and government incentives (public bus lanes access, toll waiver and charging stations). The Random-Coefficient Discrete Choice Model (referred to as the BLP model) is applied to understand the choices of heterogeneous personal consumers and business buyers. Our study is instantiated on the entire EV sales data in Norway from 2011 to 2013, as well as a set of demographics at the municipality level. The results suggest significant positive effects of BEV technology improvement, space, toll waiver and charging station density on EV demand for both personal consumers and business buyers. However, the effects on business buyers may be generally less pronounced than on personal consumers. Interestingly, bus lanes access demonstrates a negative impact for personal consumers, possibly due to consumers’ concern regarding bus lane congestion. In addition, preferences on the BEV price can vary statistically among consumers with different income levels. Compared to the BEV technology development, demographical features and municipal incentives may have generally less impacts on market shares within the BEV market.     

Influence of housing development designs on household vehicle miles traveled: A case of Iskandar Malaysia

Demand for housing in Malaysia grew noticeably in 1960s and expanded rapidly in the late 1980s and beyond as a result of rapid urbanization. The same scenario repeats itself in Iskandar Malaysia, a southern development corridor located in Johor, Malaysia where close to three hundred housing developments have been launched from pre-1980s to 2000s. These housing developments are believed to have undergone a layout design evolution affecting land use distribution, road network design, density and many other neighborhood metrics. Thus, this study investigates the impact of housing development designs on vehicle miles traveled (VMT) as they evolve over the decades. Evolution in layout design is discussed in terms of the 4Ds of urban form factors: density, diversity, design (street connectivity and intersection density) and destination accessibility (proximity). Twenty four housing areas developed within decades of pre-1980s to the 2000s were selected and travel diaries of their randomly selected households were recorded. The results obtained show that urban form and demographic factors explain almost 87% of the variances in household VMT and the three main design factors influencing VMT are housing density, proximity index (destination accessibility) and diversity index. The findings of the study show that there is a decreasing trend in density, (land use) diversity, connectivity and destination accessibility of the housing areas. While the results obtained confirm the prevalent theory on the relationship between neighborhood design and VMT, unfortunately for the study area the average VMT has been increasing with the recent housing areas.     

Built environment,travel behavior,and residential self-selection: a study based on panel data from Beijing,China

The influence of the built environment on travel behavior has been the subject of considerable research attention in recent decades. Scholars have debated the role of residential self-selection in explaining the associations between the built environment and travel behavior. The purpose of this study is to make a contribution to the literature by adopting the cross-lagged panel modeling approach to analyze a panel data, which scholars have recommended as the ideal design for studying the influence of the built environment on travel behavior accounting for the residential self-selection. To that objective, we collected activity-travel diary data from a sample of 229 households in Beijing before and after they moved from one residential location to another. We developed a two-wave structural equation model linking the residential built environment to travel behavior and taking into consideration travel-related attitudes before and after residential change. The modeling results show that individuals’ travel attitudes may change after a home relocation. We found no evidence of residential self-selection, but significant influence of the built environment on travel preference. Nevertheless, the direct influence of travel preference on travel behavior seems to be stronger than that of the built environment. As one of the very few studies to use panel data, this research presents new insights into the relationship between the built environment and travel behavior and the role of residential self-selection.

     

Reliable route guidance: A case study from Chicago

Reliable route guidance can be obtained by solving the reliable a priori shortest path problem, which finds paths that maximize the probability of arriving on time. The goal of this paper is to demonstrate the benefits and applicability of such route guidance using a case study. An adaptive discretization scheme is first proposed to improve the efficiency in computing convolution, a time-consuming step used in the reliable routing algorithm to obtain path travel time distributions. Methods to construct link travel time distributions from real data in the case study are then discussed. Particularly, the travel time distributions on arterial streets are estimated from linear regression models calibrated from expressway data. Numerical experiments demonstrate that optimal paths are substantially affected by the reliability requirement in rush hours, and that reliable route guidance could generate up to 5-15% of travel time savings. The study also verifies that existing algorithms can solve large-scale problems within a reasonable amount of time.     

改性沥青路面施工温度影响的研究

通过多年的工作总结,采用不同油源的改性沥青、面层类型和不同石质的矿料在不同路面结构上的施工情况分析,深入研究了改性沥青路面合理施工温度的影响因素,以提高路面压实度、控制路面空隙率和渗水系数为标准,提出了在各相关因素影响下的合理施工温度范围及确定依据。试验路检测结果表明,依此确定的改性沥青路面施工温度可较好地满足对沥青路面的设计要求,保证了改性沥青路面的施工质量。     

The impact of urban form on automobile travel: disentangling causation from correlation

A longstanding question within the field of transportation demand management is the strength of the relationship between urban form and mobility behavior. Although several studies have identified a strong correlation between these variables, there is as yet scant evidence to support policy interventions that target land use as a means of influencing travel. To the contrary, some of the more recent research has cast skepticism on the proposition that the relationship is causative, recognizing the possibility that households endogenously self-select themselves into communities that support their preferences for particular transportation modes. Focusing on individual automobile travel, the present study seeks to contribute to this line of inquiry by estimating econometric models on a panel of travel-diary data collected in Germany between 1996 and 2003. Specifically, we employ the two-part model (2PM)—a procedure involving probit and OLS estimators—to assess the determinants of the discrete decision to use the car and the continuous decision of distance traveled. Beyond modeling variables that capture the urban form features that are commonly suggested to influence mobility behavior, including mixed use and public transit, this study employs instrumental variables to control for potential endogeneity emerging from the simultaneity of residential and mode choices. Unlike much of the work to date, our results suggest that urban form has a causative impact on car use, a finding that is robust to alternative econometric specifications.