基于改进社会力的单向流电动自行车行为建模研究

电动自行车作为一种便捷高效的出行工具，已在许多国家被广泛使用，但对电动自行车微观行为的研究仍十分有限。在上海海事大学对电动自行车驾驶行为进行观测实验，提取电动自行车轨迹数据，以纵向间距、速度差、侧向净距、水平间距作为特征变量，利用CART(Classification and Regression Tree)决策树分类结果建立电动自行车骑行决策行为规则。然后，基于社会力模型，分别引入超越力、跟随力等改进行为力模拟电动自行车的超越、跟随等骑行决策行为。考虑公式超越力、固定值超越力和临时目标点超越力这3种超越力形式，通过实际观测数据和仿真结果比较进行参数标定和模型验证，选取单向流电动自行车行驶场景开展数值仿真分析。结果表明：临时目标点超越力的改进社会力模型在超越过程中的轨迹误差最小，电动自行车超越时所需要的横向间距与超车时横向速度、超车完成时间成正比，最佳超车横向间距为2 m。     

Engineering condition assessment of cycling infrastructure: Cyclists’ perceptions of satisfaction and comfort

The UK National Cycle Network comprises 23,660 km of cycling and walking paths of which a significant percentage is dedicated off-road infrastructure. This represents a significant civil engineering infrastructure asset that currently contributes to the provision of a sustainable transport mode option nationwide. Commuting and recreational cyclists have observed the often hazardous conditions on these paths. There are various simple measures that could be taken to improve the maintenance of such off-road paths. Reliance on walk-over surveys (direct visual inspection) and path users notifying the local authority may not be tackling maintenance in a resource efficient manner. The proposed inspection method includes the use of an instrumented bicycle to examine cycle path condition through user perception of satisfaction and quality. A questionnaire was conducted to identify the attributes of off-road cycling infrastructure people find most important in relation to their personal satisfaction. An exploratory factor analysis was undertaken on perception study data to elucidate the determination of the variables associated with perceived user satisfaction. The study has shown that people find maintenance issues to be of high importance, especially surface issues. From exploratory factor analysis of results, satisfaction has been found to load with comfort and safety. Field testing was then conducted using subjective user opinions and objective vibration data. These results were then used to assist the creation of dedicated user perception based surface condition rating-scales.     

中小城市电动车禁行应当缓行

介绍了电动自行车的发展现状,分析了我国中小城市的基本特征,从多个方面说明在中小城市适合电动自行车的发展。指出在中小城市发展电动自行车,关键是做好管理工作,并提出了具体的管理措施。     

北京的自行车交通发展探讨

通过对北京市自行车交通发展的历史与现状进行分析比较,找出存在的问题,通过SWOT分析方法,寻找北京市自行车交通发展的内部优势和劣势以及外部机遇与威胁,通过SO、WO、ST、WT战略,提出北京市自行车交通发展的具体措施,确保北京城市的可持续发展.     

Promoting Cycling for Transport: Research Needs and Challenges

Abstract

Near future travel-time information is one of the most critical factors that travellers consider before making trip decisions. In efforts to provide more reliable future travel-time estimations, transportation engineers have examined various techniques developed in the last three decades. However, there have not been sufficiently systematic and through reviews so far. In order to effectively support various transportation strategies and applications including Intelligent Transportation Systems (ITS), it is necessary to apply appropriate forecasting methods for matching circumstances in a timely manner. This paper conducts a comprehensive review study focusing on literatures, including modern techniques proposed recently, related to travel time and traffic condition predictions that are based on ‘data-driven' approaches. Based on the underlying mechanisms and theoretical principles, different approaches are categorized as parametric (linear regression and time series) and non-parametric approaches (artificial intelligence and pattern searching). Then, the approaches are analysed for their strengths, potential weaknesses, and performances from five main perspectives that are prediction range, accuracy, efficiency, applicability, and robustness.     

自行车出行综合评价方法

根据自行车出行问题的特点和影响因素构建自行车出行的评价指标体系,并利用熵权群组特征根法来确定评价指标的权重,根据自行车出行的评价信息具有模糊性和灰色双重性的特点,利用灰色模糊综合评价法建立自行车出行的二级模糊综合评价模型。最后通过对济南市自行车出行进行评价,证明此方法的正确性和有效性。     

慢行交通系统发展经验及对厦门的启示

在城市化、机动化快速发展的今天,慢行交通系统的发展因其生态环保、灵活方便、健康活力等特点而日益受到人们的关注。本文在分析慢行交通系统概念及特性的基础上,总结了国内外慢行交通系统发展先进理念及经验．提出了厦门发展慢行交通系统的几点启示。     

A Probability Model of Bicycles Crossing Vehicle-bicycle Separation Lines

Vehicle-bicycle separation lines are frequently used to isolate motor vehicles from bicycles on China's urban roads. Conflict between motor vehicles and bicycles exists in these road sections. It is regularly caused by bicycles crossing the vehicle-bicycle separation line onto the motor vehicle lane. Thus, it is imperative to research the probability of crossing travel of bicycles. First, two presumptions for bicycles to cross travel are stated. One is that bicycles need to cross the traffic marking; the other is that the space among the adjacent motor vehicle flows is available for bicycles to cross. With this observation, the probability of conflicts between motor vehicles and bicycles can be obtained as a product of their probabilities. Based on this probability, the result was summarized as follows: the probability for bicycles crossing the traffic marking obeys a negative exponential distribution, which is derived. The result was shown by theoretical analysis and was compared to actual survey data. The available probability for bicycles entering into motor vehicle flow was found by the use of a traffic survey. Therefore, a probability function was proposed with different spaces that led to a probability model for vehicle-bicycle conflicts. At last, using the survey data, the probability model proved to be correct.     

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.

杭州市电动自行车交通管理现状及源头管理对策

电动自行车的普及，在给交通参与者带来出行便利的同时，也给道路交通安全和交通秩序管理带来了一系列问题。主要以杭州市的电动自行车发展和交通管理现状为例，探讨如何从源头管理方面以合法、合理的手段解决电动自行车发展带来的问题。