Traffic density,congestion externalities,and urbanization in China

ABSTRACT

Although there is an abundant regional literature analyzing traffic congestion, only a few studies have explored extending such analysis with spatial effects. This study uses a dynamic spatial Durbin model and city-level panel data for the period 2003–14 to investigate the spatial spillover effects of traffic congestion on urbanization in China. The results show that there is an inverted ‘U’-shaped relationship between urbanization and traffic density in local and neighbouring cities, and congestion effects have appeared. In the short and long run, the spatial effects of traffic congestion have become an important force restricting the effective promotion of urbanization in China.     

THE 200 KM CITY: BRISBANE,THE GOLD COAST,AND SUNSHINE COAST

Since the 1970s, several Southeast Queensland coastal towns in areas marketed as the ‘Gold Coast’ and the ‘Sunshine Coast’ have merged with each other and joined with Brisbane to become one of the world's longest urban coastal strips. The population of this 200 km long city is fast approaching three million. This urban pattern reflects the preferences of many Australians about where and in what type of housing they would like to live. The unplanned nature of this growth raises several policy challenges relating to resource use and traffic congestion.     

智能通行证管理平台构建

随着经济的快速发展和汽车保有量的迅速增长,各类单位基于安全性的管理,可能每辆汽车都配有很多不同地点的通行证,如何放置和管理这些通行证,并制订更加合理有效的管理策略是本论文所要解决的问题.针对通行证的授权管理及显示所遇到的问题,本论文基于GPS技术、信息技术、液晶屏显示技术提出了一种新的智能通行证管理平台的构建,为解决各类通行证授权及其显示方式提出新的方案.     

Optimal route decision with a geometric ground-airborne hybrid model under weather uncertainty

Adverse weather is the dominant cause of delays in the National Airspace System (NAS). Since the future weather condition is only predictable with a certain degree of accuracy, managing traffic in the weather-affected airspace is a challenging task. In this paper, we propose a geometric model to generate an optimal combination of ground delay and route choice to hedge against weather risk. The geometric recourse model (GRM) is a strategic Probabilistic Air Traffic Management (PATM) model that generates optimal route choice, incorporating route hedging and en-route recourse to respond to weather change: hedged routes are routes other than the nominal or the detour one, and recourse occurs when the weather restricted airspace becomes flyable and aircraft are re-routed to fly direct to the destination. Among several variations of the GRM, we focus on the hybrid Dual Recourse Model (DRM), which allows ground delay as well as route hedging and recourses, when the weather clearance time follows a uniform distribution. The formulation of the hybrid DRM involves two decision variables - ground delay and route choice - and four parameters: storm location, storm size, maximum storm duration time, and ground-airborne cost ratio. The objective function has two components: expected total ground delay cost and expected total airborne cost. We propose a solution algorithm that guarantees to find the global optimum of the hybrid-DRM. Based on the numerical analysis, we find that ground-holding is effective only when combined with the nominal route. Otherwise, it is optimal to fly on the route determined by the DRM without ground delay. We also find the formula of the threshold ground-airborne cost ratio, which we call the Critical Cost Ratio (CCR), that determines the efficacy of ground delay: the higher the CCR, the more effective the strategies involving ground delay. We conclude that both ground delay and route hedging should be considered together to produce the best ATM decisions.     

Vector network equilibrium problems with capacity constraints of arcs

In this paper, we study a (weak) vector equilibrium principle with capacity constraints of arcs and common arcs in some different paths. We obtain some necessary and sufficient conditions for a (weak) vector minimum cost flow. By virtue of a (weak) Δ-equilibrium principle, we also derive some necessary and sufficient conditions for a weak vector equilibrium flow.     

论电动车管理的规范化——以武汉市为例

电动车因其行驶时无污染、低噪音、不耗油、低辐射等特点得到了迅速的发展。但在发展过程中却遇到了许多问题和困境。对此,武汉市政府应该出台有关法律法规和措施对电动车进行规范化管理,但在政策的制定时要慎重调研和分析,在考虑各方利益的前提下寻找解决问题的办法和途径。     

谈道路翻浆的原因及防治

翻浆是我国寒冷地区道路上所特有的冻害现象,在季节性冰冻地区,水文、地质条件不良路段,冬季路基土壤由于冰冻作用,路基上层水分增多,春天化冻时水分不能及时排出,使路基过分潮湿软弱,在行车作用下路面发生弹簧、裂纹、鼓包、车辙、冒泥这种现象叫做翻浆。     

浅谈公路养护的会计核算

随着公路行业改革的不断深化,公路部门经济活动的范围越来越大,经济业务的内容不断增多,现有会计科目已经不能满足会计核算需要。从2000年开始,我国公路事业单位的财务收支预算已经逐步纳入政府部门预算管理的范畴。随着公路养护会计环境发生的这些变化,就要求相关的会计核算模式进行改革。     

浅谈城市道路设计

城市道路的建设发展将面临前所未有的机遇和挑战,方便快捷的交通能推动城市建设快步进入新纪元,因此城市道路规划、设计必须在可持续发展的战略原则。笔者叙述了城市道路的可持续设计要点,和城市道路相关可持续解决方案,及可持续设计理念在我国的应用现状及前景。     

浅析公路施工中网络技术的应用

目前我国的网络计划技术在应用管理上,特别是计划执行中的监督与控制以及跟踪调整方面比较落后,基本上停留在计划的编制上。如何在施工管理中提高网络计划技术的应用水平是本文所要讨论的问题。