交通可达性与城市经济活动的空间特征分析：以北京市为例

借助开源大数据平台,提出交通可达性及城市经济活动数据采集策略,利用全局常参数和局部变参数回归模型研究北京市六环区域内两者的空间特征.相比于全局模型,局部模型能够较好地刻画交通可达性与城市经济活动间的空间异质性特征.结果表明,私人交通可达性呈现以天安门为中心径向递减的多圈层结构,公共交通呈现轨道交通沿线区域高的特点.交通可达性与经济活动匹配度具有空间非平稳性,空间分离和匹配现象并存.西北部、中部区域空间匹配特征显著,东北部、东部区域次之,西南区域空间分离现象最为严重.丰台及良乡等分离区域,宜重视道路及轨道线网等基础设施建设工作;未来科学城等私人交通匹配,公共交通分离的区域,可考虑修建轨道线路,并增加公交运营服务水平;中关村科学城、北京经济技术开发区等匹配区域,以调整交通运营管理政策为主.     

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为了定量地研究大型枢纽机场的地面交通组织系统，首先阐明了单独研究机场可达性的意义，提出了使用通达成本来描述机场可达性的新的方法，从而用化为货币形式的成本来衡量可达性。主要从快捷性，经济性和舒适性三方面来计算成本。为了量化抽象的舒适性，提出了通过“旅行者的疲劳恢复时间”来间接转化的方法。最后按照人群，地区的划分计算总通达成本加权平均。在数据的处理上，提出了使用Logit模型对两个重要参数进行标定和校正。最后，给出了几个简化算例，重点对上海浦东国际机场进行了可达性评价，然后简要地将其与其他两个国际机场进行了横向比较。结果表明：舒适性是一项不可忽略的可达性衡量指标。我国机场的可达性较国外有待提高。     

Community Severance: Where Is It Found and at What Cost?

Community severance occurs when transport infrastructure or motorised traffic divides space and people. Despite the growing awareness of its effects on the wellbeing of local communities, the problem is not usually assessed quantitatively or assigned a monetary value. This paper reviews existing practice and research on quantitative methods dealing with community severance. The problem is first decomposed into a series of questions, which are then used as a base to review the methods found in governmental guidance documents, technical reports, and academic studies. The paper ends with recommendations for the integration of severance issues into transport planning.     

A micro-level approach to measuring the accessibility of footways for wheelchair users using the Capability Model

There are a growing number of people with mobility impairments who use wheelchairs to get around the built environment. This number is likely to increase in the future due to an increasingly ageing population combined with advances in medical technology which help to overcome some of the barriers to access that have hitherto prevented people from leading as full a life as they would have liked. Footways form an integral part of the transport network and therefore it is essential they can be accessed by all people. Currently, however, there is no well-defined method to measure the accessibility of footways for wheelchair users. One aspect of a footway is the crossfall – the transverse gradient designed to facilitate surface water drainage – which adds to a wheelchair user's difficulty when progressing along the footway. This paper first reviews previous research on measuring the effect of crossfalls on wheelchair accessibility, highlighting the need for a new approach. It then proposes the Capability Model as a starting point for this new approach. The model is updated and populated with an initial capability set chosen to measure footway accessibility across footways with three different crossfall gradients (0%, 2.5% and 4%). The focus is on the physical work provided by the user to the wheelchair in order to keep it travelling in a straight line. It is shown that in order to travel in a straight line when a footway is flat only a single principal capability is required: the ability to produce sufficient force over the required distance to overcome the inertia and rolling resistance and keep the wheelchair moving at the chosen velocity. When a positive crossfall gradient is introduced a second capability is required: the ability to apply different levels of force to the left and right sides of the wheelchair. It is concluded that it is possible to measure these two capabilities and these provide a good insight into the effect of crossfalls on footway accessibility for wheelchair users.     

Integrating a traffic router and microsimulator into a land use and travel demand model

Abstract

This paper describes one of the first known attempts at integrating a dynamic and disaggregated land-use model with a traffic microsimulator and compares its predictions of land use to those from an integration of the same land-use model with a more traditional four-step travel demand model. For our study area of Chittenden County, Vermont, we used a 40-year simulation beginning in 1990. Predicted differences in residential units between models for 2030 broken down by town correlated significantly with predicted differences in accessibility. The two towns with the greatest predicted differences in land use and accessibility are also the towns that currently have the most severe traffic bottlenecks and poorest route redundancy. Our results suggest that this particular integration of a microsimulator with a disaggregated land-use model is technically feasible, but that in the context of an isolated, small metropolitan area, the differences in predicted land use are small.     

时间阈值对公交不平等评价结果的影响

时间阈值对公交可达性计算结果的影响,是否进一步影响到公交不平等评价结果,尚不明 确。以浙江省海宁市为例,用一种改进的两步移动搜索法(E2SFCA)计算公交可达性,得到 10~90 min共9个时间阈值下研究区域的总体、市区和农村公交服务的基尼系数,比较了不同时间 阈值下的基尼系数差异;按市区和农村两个群组对总体基尼系数进行分解,分析在时间阈值下群 组内和群组间不平等对总体公交不平等的影响。结果发现：随时间阈值增大而基尼系数逐渐减 小,公交不平等评价由“差距悬殊”变为“相对合理”;总体公交不平等的主要来源为群组内不平等 且贡献率在10~40 min时逐渐下降,在50~90 min时逐渐上升。研究表明,不同时间阈值会使公交 不平等评价结果出现偏差甚至得到相反的结论,有必要进一步研究消除时间阈值影响的方法。     

基于区位因素的建筑物停车配建指标分析

引用区位势概念,选择区位集聚和交通可达性两个区位因素作为影响建筑物配建指标的关键因素,重点分析距离阻抗、道路服务水平和道路等级对交通可达性的影响,并建立内部因子和区位因素的关系模型。以上海市某发展项目为例,计算考虑区位因素后建筑物停车配建指标的调整状况,并取得相应成果。     

考虑行程时间不确定性的服务设施时空可达性度量

在我国拥挤的多模式交通网络中,出行者的行程时间具有较大的不确定性.行程时间不确定性是影响人们出行行为选择的重要因素,对于某些重要活动(如就医等),人们对行程时间的可靠度有较高要求.本文以南京市玄武区综合医院的时空可达性为例,采用引力模型和行程时间预算模型深入探索多模式交通网络中服务设施的时空可达性,提出了考虑行程时间不确定性的时空可达性度量方法,针对不同交通模式分析了出行者的风险规避行为,为城市多模式交通规划和土地利用布局提供了有效依据及评价指标.研究表明,对于不同的交通模式,在不同可靠性下服务设施的时空可达性具有显著差异.     

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旅游交通可达性分析能够为区域旅游交通规划提供理论依据,而高速铁路的开通将直接改变区域旅游交通可达性格局.本文采用加权平均旅行时间作为节点城市旅游交通可达性的评价指标,利用Arc GIS可视化平台分析旅游交通可达性空间格局,获取高铁开通前后云南省旅游交通可达性的演变特征.在此基础上,对公路、铁路、航空和高铁的权重进行灵敏度分析,辨识出旅游交通可达性对各种交通方式权重的敏感度.结果表明:高铁途经的各城市客源地到达云南的旅游交通可达性水平均有大幅提升,旅游交通可达性的时空收敛效应显著,省外城市到达昆明的旅游交通可达性对铁路权重的敏感度较大;高铁开通之后,云南省旅游交通可达性格局总体呈现以昆明为中心向外围区域递减的"核心—外围"模式;高铁开通前后,云南省内旅游交通可达性的变化幅度较小,地区间的总体差异也不断缩小,省内高铁途经城市的旅游交通可达性对高铁权重的敏感度较大.     

河南省高速公路网络发育程度评价与分析

作为河南省区域联系的快速通道,高速公路网络对河南省国民经济与社会发展起着至关重要的作用.通过选取通达指数、伸展指数、趋中指数等指标,以河南省18个中心城市的最短路径矩阵为基础,对河南省区域高速公路网络的发育程度进行了定量评价.结果显示,河南省高速公路网络发育程度在空间格局上呈现明显的“核心—外围”模式,通达指数最高的城市集中在中心城市郑州周围,较低的城市分布在外围地区;趋中指数排序与通达指数排序相吻合;河南省边缘地区城市的通达性需要提高,区域高速公路网络需要进一步完善.