Preventive maintenance of road pavement with microsurfacing—an economic and sustainable strategy

To ensure a good quality level of road pavements, it is essential to perform preventive maintenance before they are irreparably damaged. Treatments for preventive maintenance are a solution that is recognized but still in the acceptance phase; effective models covering different combinations of techniques and intervention times and assessing economic and environmental benefits are lacking. The present study aimed to respond to the abovementioned issues, using microsurfacing as the subject of analysis. Several structures and different interventions were evaluated, conducting an economic analysis over their life cycles and an environmental study evaluation using emission factors. The most advantageous solution included the maximum possible number of treatments of preventive maintenance with microsurfacing applied consecutively. This scenario ensures economic and environmental benefits. Additionally, it became clear that it is economically advantageous to design pavements for longer lifetimes.     

Travel,roads, risks and volunteers

International volunteers often travel to destinations (low- and middle-income countries) that carry a greater chance of being involved in a road-related injury and a possible fatality. Within this cultural exchange, tourists move from safe roads and cars to those that are potentially unsafe. Is this all part of the adventure of volunteering or should the tourist industry take some responsibility? This paper highlights the intersection between tourism and road injury and fatality risks (as pedestrians or in vehicles) with special attention to the longer term volunteer traveller. Social science theory underpins some of the discussions around risk and travel. A brief consideration of the international road traffic death and injury crisis and the emergence of the recognition that this impacts upon tourist safety is explored as backdrop to discussions. Tourism relies upon the ability for people to travel in and around the countries they travel to, often taking on the local travel arrangements prevalent in their destination. These local travel arrangements enable leisure tourists to explore their destination and volunteer travellers to live and work as locals. Is it time to consider and further the research on road risks as a growing feature of tourism?     

交通网络演变对中心城市腹地范围的影响——以江西省为例

交通网络演变对中心城市腹地范围的变化产生关键影响.选取1994、2002、2010和2020年4个年份作为时间断面,在江西省社会经济数据及交通地理数据的支持下,应用时间距离和场强模型对江西省中心城市的小时圈影响范围和场强腹地进行了划分,得到中心城市两种类型腹地范围的演变格局.结果表明:交通网络的优化可以给中心城市腹地内部带来显著的时空压缩效应;中心城市腹地范围的变化同时受到自身及周边中心城市交通路网演变的影响;交通网络演变对中心城市腹地范围的影响显著,表现出多样化特征.     

中国畜产品出口贸易效率及潜力研究——以“丝绸之路经济带”沿线国家为例

目的 文章分析了中国对“丝绸之路经济带”沿线国家畜产品出口贸易效率及贸易潜力,以挖掘贸易潜力,推进双边畜产品贸易发展和畜牧产业合作。方法 运用2001—2020年面板数据构建随机前沿引力模型,测度中国对沿线国家畜产品贸易效率及潜力,并对经济规模、对外投资、地理位置等影响因素进行实证分析。结果 中国与沿线国家的经济发展水平、中国对外投资、是否加入WTO都对中国畜产品出口沿线国家有显著正向促进作用,而沿线国家的政治稳定程度和畜牧业发展水平则对中国畜产品出口该地区有抑制作用。结论 中国对沿线国家畜产品出口的贸易效率极不平衡,对亚欧经济带国家的出口效率远高于中亚及环中亚经济带;畜产品出口贸易潜力从高到依次为环中亚经济带、中亚经济带和亚欧经济带,其中,对亚美尼亚、哈萨克斯坦、阿富汗和伊朗等中西亚国家的畜产品市场潜力极大。我国应积极推进经济走廊的建设,完善自身贸易环境,以在“一带一路”倡议下提高中国畜产品出口贸易效率,释放贸易潜力,推动双边贸易的有效发展。     

沥青路面产生不平整的原因及处理措施

本文从路面设计、路面施工、养护管理及其他环节,结合本人的工程实践,分析了沥青路面早期破坏的原因。     

新时期加强市政道路工程建设成本控制的有效策略

工程建设成本控制是施工项目盈亏的关键。市政道路已成为城市发展的关键基础设施,如何控制工程建设成本,争取以较少的投入收获高质量的产出,是本文要阐述的重点,在此基础上提出了控制成本的方法策略。     

Domestic air passenger traffic and economic growth in China: Evidence from heterogeneous panel models

This paper applies recent panel methodology to examine the short-run dynamics, the long-run equilibrium relationships and the Granger causal relationship between economic growth and domestic air passenger traffic. It is based on the quarterly panel data of 29 provinces in China from the period of 2006Q1 to 2012Q3. Tests for panel unit roots, cointegration in heterogeneous panels and panel causality are employed in a bi-variate panel vector error correction model (PVECM), which is estimated by the system generalized moment method (SYS-GMM). The results show evidence of a long-run equilibrium relationship between economic growth and domestic air passenger traffic. Specifically, 1% increase in the air passenger traffic is found to lead to an increase of 0.943% in real gross domestic product (GDP). A long-run and strong bi-directional Granger causal relationship is found between these two series. It is also found that there is a short-run uni-directional Granger causality running from the domestic air passenger traffic to the economic growth.     

Short- and long-run impacts of gasoline price and macroeconomic factors on road traffic safety in Nigeria

This paper examined the short- and long-run impacts of gasoline price, macroeconomic factors and road length on road traffic crashes, injuries and fatalities in Nigeria. Annual data from 1995 to 2019 and autoregressive distributed lag approach were employed. Results suggest that gasoline price, per capita income, road length and population density significantly influence road safety outcomes. Gasoline price has a positive short-run impact on crashes, injuries, and fatalities contrary to findings in developed countries. Road crashes tend to decrease when income increases in the short term. Population density leads to improvement in road safety outcomes while road length exacerbates it. Government's policy on gasoline price increase could worsen road safety outcomes unless it is accompanied by improvement in road infrastructure, safe public transport and economic growth,     

危化品储运的数字孪生系统设计

数字孪生技术近年来取得了长足的发展,其凭借对真实场景的细粒度与动态性模拟,已经广泛应用于智能建造、智慧交通、航空航天等领域。危化品的储运一直是事故的重点多发环节,然而数字孪生技术在这一领域的应用仍然较少。基于数字孪生的技术特点,首先分析数字孪生当前的技术核心与实现方式,然后阐述危化品储运数字孪生系统的基本功能,设计系统的基本架构,最后以天然气接收站为例,展示数字孪生技术在LPG槽车装卸与运输过程中的应用前景。分析表明,以数字孪生技术为底座,依托传感器获取的多源数据流,在应用层衍生满足用户需要功能的设计,能够为实现危化品储运“主动安全”提供一定技术保障。     

The circular road revisited: Uniqueness and supermodularity

The model of the circular road has proved to be a popular model of oligopolistic interaction, yet its theoretical properties are not fully explored. In this paper I extend the uniqueness result of price equilibrium in the circular road with equidistant locations from quadratic transportation costs, to a class of convex power transportation costs, i.e. I show uniqueness in oligopoly for a class of utility functions of the consumers. I show that the associated game is supermodular and dominance solvable. The paper also discusses possible extensions and limitations of the model.