Evasive manoeuvres with a steering robot

In the pursuit of an objective rating on vehicle stability performance, it is always desirable to reduce disturbances and inconsistencies during experimental evaluations, especially the ones introduced by human drivers. This paper presents the development of a steering robot designed for closed-loop steering tasks during evasive manoeuvres. It describes the controller structure and discusses experimental results, in addition to simulation/vehicle model verifications and theoretical control analysis.     

A GIS‐based method to identify cost‐effective routes for rural deviated fixed route transit

Deviated fixed route transit (DFRT) service connecting rural and urban areas is a growing transportation mode in the USA. Little research has been done to develop frameworks for route design. A methodology to explore the most cost‐effective DFRT route is presented in this paper. The inputs include potential DFRT demand distribution and a road network. A heuristic is used to build possible routes by starting at urban cores and extending in all network directions in certain length increments. All the DFRT routes falling in the length range desired by the users are selected. The cost effectiveness of those routes, defined by operating cost per passenger trip, is compared. The most cost‐effective route is selected and presented in a GIS map. A case study illustrates the methodology in several Tennessee metropolitan regions. The most cost‐effective route length is case specific; some routes (e.g. those out of our Nashville case) are most cost effective when short, while others (e.g. those out of Memphis) are most cost effective when long. Government agencies could use the method to identify routes with the lowest operating cost per passenger given a route length or an operating cost budget. Copyright © 2016 John Wiley & Sons, Ltd.     

特大城市交通出行预测:中国面临的挑战与机遇

作为城市交通规划的一个重要组成部分,城市交通出行预测的发展已经走过了60年。最初的研究工作于20世纪50年代在北美展开,随后延伸到欧洲、澳大利亚、新西兰和南美洲以及中国等发展中国家。作为一个相对成熟的领域,交通规划依然包含着许多新的研究方向,同时专业人员在正确合理的使用商业软件方面还有一定的困难。中国正在经历高速的城市化进程,这意味着对道路、公交系统,机场以及城际间高速公路建设有大量的投资。合理的投资决策需要对未来中国交通拥挤的都市进行出行预测。为了更好的了解中国交通出行预测的发展现状,笔者和几个大城市的交通规划部门以及大学的相关院系进行了探讨和交流。此文的初衷是记录下从会谈中所获得的有普遍意义的发现与印象,以及提供给参加讨论者的意见。     

电动自行车交通发展的主要趋势——近10年文献综述

电动自行车是交通市场增长最快的领域之一,2012年总销售量超过3100万辆.相关研究的数量不断上升,鉴于此,对过去蓬勃发展的与电动自行车最相关的主题进行综合分析.将研究重点放在电动自行车交通及需要注意的最关键的研究缺口方面,而非休闲娱乐.中国的电动自行车销量在世界占领先地位,荷兰、德国紧随其后.电动自行车能够以较少能耗保持一定速度,也有研究发现电动自行车能增加自行车使用率.电动自行车有潜力取代传统机动交通方式(内燃式),但在取代传统自行车方面所扮演的角色仍存在争议.电动自行车不仅有益身体健康,并且相同行驶里程下,碳排放水平显著低于小汽车.在某些地区,安全问题上升到政策层面,目前电动自行车的数量已经足以搜集到丰富的安全数据.尽管如此,关于电动自行车的研究目前仍处于萌芽阶段.随着电动自行车数量的不断上升,为了向政策制定者以及整个行业提供必要的数据,相关领域的进一步研究需求也日益增长.     

The transition to electric bikes in China: history and key reasons for rapid growth

Annual electric bike (e-bike) sales in China grew from 40,000 in 1998 to 10 million in 2005. This rapid transition from human-powered bicycles, buses and gasoline-powered scooters to an all-electric vehicle/fuel technology system is special in the evolution of transportation technology and, thus far, unique to China. We examine how and why e-bikes developed so quickly in China with particular focus on the key technical, economic, and political factors involved. This case study provides important insights to policy makers in China and abroad on how timely regulatory policy can change the purchase choice of millions and create a new mode of transportation. These lessons are especially important to China as it embarks on a large-scale transition to personal vehicles, but also to other countries seeking more sustainable forms of transportation.

Use characteristics and demographics of rural transit riders: a case study in Tennessee

Intercity bus (ICB), deviated fixed route transit (DFRT) and demand responsive transit (DRT) are three major modes of rural public transportation. This paper focuses on the characteristics and motivations of DFRT and DRT riders, compared to non-riders, in Tennessee. A rural DFRT rider survey, a rural DRT rider survey and a rural (non-rider) resident survey were performed. It is found that DFRT and DRT riders have similar demographics to ICB riders. The most common trip purpose for DFRT and DRT passengers is medical care, which is different from ICB trips. Ninety percent of the riders have difficulty finding alternative transportation modes, suggesting they are captive riders, not choice riders. Regression results indicate that people choosing transit modes tend to have lower personal and household income, own fewer cars, to not be homeowners, and be of non-white race. Rural residents who receive more education are more likely to be open-minded to use rural transit.     

Comparative environmental impacts of electric bikes in China

Electric two-wheelers have become a significant mode of transportation in China in the past decade. Though marketed and publicized by some as zero-emission vehicles, little past research has been done to quantify the environmental impacts of electric two-wheelers in China. This paper quantifies some of the environmental impacts of the production processes and use phase of electric two-wheelers and compares them to the environmental impacts of competing modes, including bicycles, buses, motorcycles and cars. The use phase emissions are quantified geographically with significantly higher emissions in coal rich regions, compared to regions relying more on hydropower. The results show that electric two-wheelers emit several times lower pollution per kilometer than motorcycles and cars, have comparable emission rates to buses and higher emission rates than bicycles. Lead is one pollutant on which electric two-wheelers perform poorly, because of their use of lead acid batteries.