交通建设领域“拖欠”问题分析

<正>工程建设领域拖欠问题由来已久,曾经在上世纪八十年代末九十年代初困扰经济领域的企业三角债问题就是其前身,只不过是由生产、销售领域转向了建筑施工和分配领域。近年来,国家加快基础设施建设步伐,做为先行产业之一的交通基础设施建设得以长足发展,为经济和社会发展做出了突出的贡献。但是,在     

全国交通运输系统工程建设领域突出问题专项治理工作推进会侧记 排查工作顺利完成 “阳光工程”持续推进

6月12日至13日,全国交通运输系统工程建设领域突出问题专项治理工作推进会在广州召开,在这次会议的分组讨论环节,参会代表对有些问题探讨之激烈、深入使记者耳目一新,本文撷取其中片段,以飨读者。     

高速公路隧道工程建设技术现状与问题探讨

文章针对广西高速公路隧道快速发展的现状,介绍了目前广西隧道工程建设中主要采用的勘测、设计、施工和检测技术,对隧道建设中存在的几个突出问题提出了解决的思路,具有一定的实践意义。     

构建完善我国公路水运工程建设信用管理体系

以信用为手段开展事中事后监管是政府行政职能转变的重要方向,基于现行公路水运工程建设领域信用体系建设现状及存在问题,对标国内外先进经验,构建了"五大主体、三大建设、一个平台、一套机制"的公路水运工程建设质量安全信用管理体系("5311")。该体系以从业单位和关键人员为管理对象,以制度体系建设、评价体系建设和监督体系建设为核心内容,以信用信息管理平台为纽带和手段,以奖惩机制作为保障,为切实提升公路水运工程建设质量安全水平,建设"交通强国"夯实基础。     

铁路建设领域农民工工资治欠问题及对策分析

文章结合广西铁路建设农民工工资治欠工作,根据国家当前对工程建设行业农民工工资治欠工作的要求,分析铁路建设领域中存在的农民工欠薪问题,提出加强工程建设农民工工资治欠工作的对策。     

最低评标价法在沙颍河复航工程中的应用

工程建设领域的腐败行为一直是个十分敏感的问题,据有关部门统计,近年来查处的行贿受贿案件中,发生在建筑领域的竟占三分之一以上,许多干部在工程建设中中箭落马,造成这一事实的根本原因是我国现行的建设工程制度还不够完善,尤其是我们的评标方式还有待于近一步修改完善。最低     

特殊性岩土对城市轨交工程建设影响的分析

特殊性岩土问题是城市轨交工程建设中重要的地质风险因素,直接影响到工程的质量安全和投资造价。通过总结和归纳目前苏州轨交工程建设中遇到的特殊性岩土的类别、成因及其分布特征,结合工程建设中存在的一些问题,着重分析了特殊性岩土对轨交工程建设的影响,并提出相应的防治措施。     

提高路桥施工项目管理的做法分析与阐述

如今,随着经济的发展,人们对于出行上的方便、舒适要求越来越高。同时也为了能够加强城市之间的相互联系,加强城市间的经济共同发展,这些因素就使得路桥施工重要性越来越突出。在我国交通行业中路桥工程建设有着非常重要的作用,是城市建设与发展的核心之一。那么我们就有非常有必要对路桥工程建设的方方面面进行探讨研究,以提高路桥施工项目管理的水平,并通过大量的时间经验和资料调查分析来发现其中存在的问题,针对这些问题等提出应对策略,进而提高路桥工程建设的整体质量,从而使我国的道路桥梁施工建设得到更好的发展。     

论健全交通建设工程质量执法监督体系

近年来，国家加大了对交通基础设施的投入力度，投资规模逐年加大，交通事业发展取得了前所未有的成就。但是也应该看到，在交通建设迅猛发展的同时，交通基础设施工程建设质量已经成为交通建设中的突出问题，引起了社会各界的广泛关注。健全交通基础设施工程质量执法监督体系尤为紧迫和必要。     

交通执法专项整治获成效

2021年5月起,交通运输部在全国各地开展了交通运输执法领域突出问题专项整治行动.目前专项整治行动已经完成了全面摸排和自查自纠,进入深入整改阶段.     

Bicycling renaissance in North America? An update and re-appraisal of cycling trends and policies

This paper reviews trends in cycling levels, safety, and policies in Canada and the USA over the past two decades. We analyze aggregate data for the two countries as well as city-specific case study data for nine large cities (Chicago, Minneapolis, Montréal, New York, Portland, San Francisco, Toronto, Vancouver, and Washington). Cycling levels have increased in both the USA and Canada, while cyclist fatalities have fallen. There is much spatial variation and socioeconomic inequality in cycling rates. The bike share of work commuters is more than twice as high in Canada as in the USA, and is higher in the western parts of both countries. Cycling is concentrated in central cities, especially near universities and in gentrified neighborhoods near the city center. Almost all the growth in cycling in the USA has been among men between 25-64 years old, while cycling rates have remained steady among women and fallen sharply for children. Cycling rates have risen much faster in the nine case study cities than in their countries as a whole, at least doubling in all the cities since 1990. They have implemented a wide range of infrastructure and programs to promote cycling and increase cycling safety: expanded and improved bike lanes and paths, traffic calming, parking, bike-transit integration, bike sharing, training programs, and promotional events. We describe the specific accomplishments of the nine case study cities, focusing on each city’s innovations and lessons for other cities trying to increase cycling. Portland’s comprehensive package of cycling policies has succeeded in raising cycling levels 6-fold and provides an example that other North American cities can follow.     

Energy use in passenger transport in OECD countries: Changes since 1970

This paper analyzes some of the changes that took place in the structure of energy use for passenger travel in industrialized countries. Data is presented on energy use and travel activity for the four major modes of travel — automobile, bus, rail and air — for eight OECD countries: the United States, Japan, the United Kingdom, West Germany, France, Italy, Sweden, and Norway. We use the Laspeyres and Divisia indices to analyze the causes of the change in energy use between 1970 and 1987. The total change in energy use for travel is explained by changes in domestic passenger transport volumes, the mix of modes of travel, and the energy intensities of each mode. We have found two important effects that have a fundamental impact on energy use for travel since 1970. First, shifts among modes of transport towards more energy-intensive ones and large increases in volumes of travel (measured in passenger-kilometers) increased energy use for travel in many OECD countries, often more rapidly than the overall growth in GDP. Second, energy intensities, measured in mJ/passenger-kilometer, of passenger transport fell only in a few countries between 1970 and 1987. Even though individual automobiles have become more energy-efficient, greater size, power, and weight, worsening traffic conditions in Japan and Europe, and fewer people in cars restrained or even offset efficiency improvements. Particularly notable are the increases in intensities in Japan and Germany. The most important exception to this trend was the United States, but the intensities of land-based travel remain higher there than in most other countries. These findings lead to a pessimistic outlook for future energy use for travel. After all, if little or no energy was saved during the decades of high fuel prices, what can be expected in the 1990s?     

基于LEAP模型的佛山市交通碳排放研究

随着城市化的发展,珠三角城市交通能源消耗和碳排放迅速增长。为了探讨珠三角城市低碳交通的发展方向,本文采用LEAP模型,以珠三角的佛山市为例,模拟了不同情景下交通总量、陆运和水运的能源消耗、能源结构和碳排放由2011至2030年的变化情况;并据此提出了珠三角城市低碳交通发展对策。结果表明:水运在交通运输中所占份额逐渐被陆运替代,将形成陆运为主、水运为辅的交通模式;在交通总量、陆运和水运等的交通能耗及碳排放方面,低碳情景均小于基准情景,且呈水运小于陆运的态势;而清洁能源使用比重的增加则有利于交通领域的低碳发展。珠三角城市低碳交通发展需关注陆运交通,提高清洁能源在陆运中的使用比重,优化陆运与水运的交通布局,提高运输及能源利用效率。     

Persistence of walking in Chile: lessons for urban sustainability

ABSTRACT

An extensive body of work from the urban planning, health, and other disciplines has documented the importance of walking to urban sustainability from health, safety, security, environmental and other perspectives. These studies come mainly from countries in North America and Europe, where the majority of the population relies on cars for transportation. Notwithstanding, in many countries in the Global South, walking remains a majority transport mode, while cars increasingly dominate the urban streetscape, but are accessible only to a minority of the population. Chile provides fertile terrain for studying this phenomenon. This article reviews current practice and recent research of walking in Chile, in light of international findings regarding walkability, equity and urban sustainability. To elaborate an overview of the depth and breadth of walking in Chile, an interdisciplinary team conducted a literature review, examined relevant case study material from experience from Chile and in particular from Santiago, and triangulated this mainly qualitative data with results from the origin-destination survey applied in Chile’s main cities, Chilean traffic safety data) and results from official transport reports of other Latin American cities [Tirachini, A. (2019). South America: The challenge of transition. In J. Stanley & D. Hensher (Eds.), A research agenda for transport policy. Northampton, MA: Edward Elgar Publishing]. Findings show that despite priority public investments that have largely prioritised infrastructure for cars, walking in Chile has remained as the majority transport mode up until today, especially for lower-middle income groups, and particularly for care-related tasks performed mainly by women. In this sense, walking in Chile has proven remarkably persistent. The importance of walking as the main transport mode, against the odds, reflects economic, cultural, and urban form determinants, which are explored in this article. Furthermore, a recent upsurge in public interest and community design initiatives to improve walking, particularly the generation of a Chilean approach to “complete streets” has emerged, opening up opportunities to challenge Chile’s version of automobility in favour of more equitable, active and public transportation modes. There is, therefore, in Chile an opportunity to prioritise the walking mode, improve infrastructure for walkers and build from preserving current high pedestrian modal shares, rather than having to reverse widespread car use, as occurs in many countries in Europe and North America. This potential is highly relevant as these conditions are similar to those in other Latin American cities and, potentially, other cities elsewhere in the Global South.     

The growing gap in pedestrian and cyclist fatality rates between the United States and the United Kingdom,Germany, Denmark,and the Netherlands, 1990–2018

ABSTRACT

Using official national data for each country, this article calculates trends in walking and cycling fatalities per capita and per km in the USA, the UK, Germany, the Netherlands, and Denmark. From 1990 to 2018, pedestrian fatalities per capita fell by 23% in the USA vs. 66%–80% in the other countries; cyclist fatalities per capita fell by 22% in the USA vs. 55%–68% in the other countries. In 2018, pedestrian fatality rates per km in the USA were 5–10 times higher than in the other four countries; cyclist fatality rates per km in the USA were 4–7 times higher. The gap in walking and cycling fatality rates between the USA and the other countries increased over the entire 28-year period, but especially from 2010 to 2018. Over that 8-year period, per-capita fatality rates in the USA rose by 19% for pedestrians and 11% for cyclists; per-km fatality rates rose by 17% for pedestrians and 33% for cyclists. By comparison, fatality rates either fell or remained stable in the four European countries. We reviewed the relevant literature to identify factors that might help explain the much lower walking and cycling fatality rates in Europe compared to the USA. Possible explanatory factors include better walking and cycling infrastructure; lower urban speed limits; fewer vehicle km travelled; smaller and less powerful personal motor vehicles; and better traffic training, testing, and enforcement of traffic regulations. We recommend that the USA consider implementing an integrated package of mutually reinforcing safety measures such as those that have been successfully implemented in the Netherlands, Denmark, and Germany to reduce pedestrian and cyclist fatality rates.     

新疆钢渣成渣工艺及集料化分析研究

本文通过对新疆不同成渣工艺及钢渣矿物化学组成、稳定性、物理指标进行分析,阐述了新疆钢渣技术现状,推动钢渣在公路工程中的资源化利用。新疆钢渣主要集中于北疆的乌昌地区,在热泼法和热闷法两种成渣工艺下,钢渣化学矿物成分相对稳定,属于高碱活性材料,并具有胶凝特性,同时具有一定工程级配。f-CaO含量热闷法小于热泼法,并且在自然环境下可陈化降解,有利于钢渣的稳定性。钢渣物理指标优于新疆常规碎、砾石材料,可集料化用于公路工程建设。此外,钢渣在工程应用中具有显著的经济和生态效益。     

Heavy metals and metalloid contamination in Louisiana Lake Pontchartrain Estuary along I-10 Bridge

In this study, HMs concentration in sediments and water from the Lake Pontchartrain estuary along the I-10 Bridge were investigated in two seasons to evaluate the level of contamination and to assess the effect of vehicular traffic. Vehicular traffic has led to HMs such as As, Cd, Cr, Pb, Zn, Ni, and Cu accumulation in sediments along the bridge. The HMs content in water especially in summer increased due to high temperature which led to release of HMs from the sediments. The level of pollution attributed to anthropogenic activities was evaluated using several pollution indicators. The overall HMs bioavailability and EFs was mostly high in summer and the concentration of the HMs in both sediments and water was highly influenced by the season and the distance from the highways. The content of As and Cd in lake sediments were higher than the background values (BGV) for both seasons (spring and summer), and Cr and Pb in sediments were higher than the BGV in most sampling points in the spring. According to Sediments Quality Guidelines (SQGs), heavy metals except for As have low biotoxicity, and As could potentially result in harmful effects on the aquatic organisms. The relationship between As and vehicular traffic is less studied so our finding stress the need for further study on source of As in Lake Pontchartrain sediments.     

Urban walkability considering pedestrians’ perceptions of the built environment: a 10-year review and a case study in a medium-sized city in Latin America

ABSTRACT

Numerous methodologies measuring walkability have been developed over the last years. This paper reviews the Walkability Index (WI) literature of the last decade (2009–2018) and highlights some limitations in the current approaches. Only a few studies have evaluated walkability in Latin America, mainly in big cities but not in medium and small-sized cities in the region, which present their own urbanisation dynamics, security issues, sidewalk invasion problems, and poor planning. Furthermore, most WIs in the literature use objective mesoscale variables to assess walkability in a given area. This paper contributes to filling these gaps by generating new evidence from a medium-sized city in Latin America to question if characteristics of the built environment encourage walking trips, as found in the literature, are transferable among regions. The study also proposes a novel index comprised of microscale and mesoscale built environment variables to assess walkability using virtual tools and considering users’ perceptions. The WI estimation relies on ranking probability models. The results of the case study suggest that subjective Security and Traffic Safety are the most crucial factors influencing walkability in these kind of cities, which is different from what is found in the literature from cities in developed countries where Sidewalk Condition and Attractiveness are the most important factors. Security appeared to be strongly associated with a subjective dimension, represented by the fear of crime or perceived risk for crime, instead of the actual occurrence of crimes. This result evidences the importance of the physical attributes of the real world and how they are captured, judged, and processed by pedestrians. Then, regional transferability of WIs needs to be done carefully. Finally, results in this paper highlight the importance of microscale built environment characteristics in the WI formulation in these cities. Results are in line with other research in some cities of the region, which found that microscale variables such as pavement quality and presence of obstacles on the sidewalks are relevant components to promote walkability.     

含蜡热油管道清管过程的卡堵风险分析

现场清管作业时,清管器经常被卡堵,严重时会影响生产.因此,为降低热油管道清管过程中的卡堵风险,根据清管器在含蜡热油管道中的受力情况和运行规律,结合输油管道的现场运行管理经验,分析含蜡热油管道清管过程可能遇到的卡堵,对此提出可靠的应对措施,以杜绝含蜡热油管道周期性清管中各种事故的发生,保证热油管道清管工作的安全进行,为今...     

Technical and environmental effects of biodiesel use in local public transport

Biodiesel use in local public transport could be especially significant in improving air quality in cities. The purpose of the experiments described in this paper was to evaluate the various (10, 20 and 50%) blends of biodiesel with diesel in the context of the engine and pollution aspects. As regards the experimental use of these findings on municipal buses, these experiments were the first reference in Hungary. The ages (15–20 years) and types of buses (Ikarus-280, Ikarus-260) used in the experiments are still common vehicles in Hungarian public transport. During our measurements, there was a significant difference between the change in fuel consumption of articulated and solo buses in traffic when compared to test bench measurements. The proportion of the engine performance reduction is nearly the same as that for biodiesel share in the blends. Most pollutants were decreasing (both at idle and full rpm), but this reduction is not directly proportional to the increase of the blending percentage. However, as for CO₂, emission increase was observed in the case of idle rpm in comparison to normal diesel operation, even though this phenomenon was not due to biodiesel use, but the catalytic converter and the fact that biodiesel was used for the first time in the engine concerned.