Spatial Morphology Lab 01. International laboratory for comparative research in urban form. Street networks, Sweden - Motorised network of Gothenburg

GIS-datasets for the Street networks of Stockholm, Gothenburg and Eskilstuna produced as part of the Spatial Morphology Lab (SMoL).

The goal of the SMoL project is to develop a strong theory and methodology for urban planning & design research with an analytical approach. Three frequently recurring variables of spatial urban form are studied that together quite well capture and describe the central characteristics and qualities of the built environment: density, diversity and proximity.

The first measure describes how intensive a place can be used depending on how much built up area is found there. The second measure captures how differentiated the use of a place can be depending on the division in smaller units such as plots. The third measure describes how accessible a place is depending on how it relates with other places. Empirical studies have shown strong links between these metrics and people's use of cities such as pedestrian movement patterns.

To support this goal, a central objective of the project is the establishment of an international platform of GIS data models for comparative studies in spatial urban form comprising three European capitals: London in the UK, Amsterdam in the Netherlands and Stockholm in Sweden, as well as two additional Swedish cities of smaller size than Stockholm: Gothenburg and Eskilstuna.

The result of the project is a GIS database for the five cities covering the three basic layers of urban form: street network (motorised and non-motorised), buildings and plots systems.

The data is shared via SND to create a research infrastructure that is open to new study initiatives. The datasets for Amsterdam will also be uploaded to SND. The datasets of London cannot be uploaded because of licensing restrictions.

The street network GIS-maps include motorised and non-motorised networks. The motorised networks exclude all streets that are pedestrian-only and were cars are excluded. The network layers are based on the Swedish national road database, NVDB (Nationell Vägdatabas), downloaded from Trafikverket (https://lastkajen.trafikverket.se, date of download 15-5-2016, last update 8-11-2015). The original road-centre-line maps of all cities were edited based on the same basic representational principles and were converted into line-segment maps, using the following software: FME, Mapinfo professional and PST (Place Syntax Tool). The coordinate system is SWEREF99TM.
In the final line-segment maps (GIS-layers) all roads are represented with one line irrespectively of the number of lanes, except from Motorways and Highways which are represented with two lines, one for each direction, again irrespectively of the number of lanes. We followed the same editing and generalizing procedure for all maps aiming to remove errors and to increase comparability between networks. This process included removing duplicate and isolated lines, snapping and generalizing. The snapping threshold used was 2m (end points closer than 2m were snapped together). The generalizing threshold used was 1m (successive line segments with angular deviation less than 1m were merged into one). In the final editing step, all road polylines were segmented to their constituting line-segments. The aim was to create appropriate line-segment maps to be analysed using Angular Segment Analysis, a network centrality analysis method introduced in Space Syntax.

All network layers are complemented with an “Unlink points” layer; a GIS point layer with the locations of all non-level intersections, such as overpasses and underpasses, bridges, tunnels, flyovers and the like. The Unlink point layer is necessary to conduct network analysis that takes into account the non-planarity of the street network, using such software as PST (Place Syntax Tool).

本数据集为空间形态实验室（Spatial Morphology Lab，简称SMoL）项目产出的斯德哥尔摩、哥德堡与埃斯基尔斯蒂纳的街道网络地理信息系统（Geographic Information System，GIS）数据集。
SMoL项目旨在依托分析性方法，构建城市规划与设计研究的成熟理论与方法论体系。研究聚焦空间城市形态中三大高频变量，可较为全面地捕捉并刻画建成环境的核心特征与品质：密度、多样性与可达性。
第一项指标衡量场地的开发强度，取决于该区域建成用地的占比；第二项指标反映场地的用地分化程度，基于地块等更小单元的划分情况；第三项指标表征场地的可达性，取决于其与其他场地的空间关联关系。实证研究表明，此类指标与市民的城市使用行为（如步行流动模式）存在显著关联。
为支撑该研究目标，项目的核心任务之一是搭建面向空间城市形态比较研究的GIS数据模型国际平台，涵盖五座欧洲城市：英国伦敦、荷兰阿姆斯特丹、瑞典斯德哥尔摩，以及两座规模小于斯德哥尔摩的瑞典城市——哥德堡与埃斯基尔斯蒂纳。
本项目最终产出覆盖上述五座城市的GIS数据库，包含三大城市形态基础图层：街道网络（机动交通与非机动交通）、建筑与地块系统。
该数据集通过SND共享，以打造开放的研究基础设施，接纳新的研究课题。阿姆斯特丹的数据集亦将上传至SND，而伦敦的数据集因授权限制无法公开上传。
本次产出的街道网络GIS地图包含机动与非机动交通网络两类。其中机动交通网络排除所有仅限行人通行、禁止机动车驶入的道路。网络图层基于瑞典交通局（Trafikverket）发布的瑞典国家道路数据库（Nationell Vägdatabas，NVDB）构建，下载自https://lastkajen.trafikverket.se，下载日期为2016年5月15日，数据库最新更新日期为2015年11月8日。所有城市的原始道路中心线地图均遵循统一的基础表征原则进行编辑，并通过FME、MapInfo Professional及空间句法工具（Place Syntax Tool，简称PST）转换为线段地图。坐标系采用SWEREF99TM。
在最终生成的线段地图（GIS图层）中，除高速公路和快速路外，所有道路均以单条线段表示，不考虑车道数量；高速公路和快速路则以双向双线段分别表示，同样不考虑车道数量。所有地图均采用统一的编辑与概化流程，以消除错误并提升各网络间的可比性。该流程包括移除重复与孤立线段、节点匹配与线条概化：本次使用的节点匹配阈值为2米（间距小于2米的端点将被合并），线条概化阈值为1米（连续线段的角偏差小于1米将合并为单一线段）。在最终编辑环节，所有道路多段线均被拆分为其组成的独立线段，以适配角度段分析（Angular Segment Analysis）——一种由空间句法（Space Syntax）提出的网络中心性分析方法——的使用需求。
所有网络图层均配套"非平面交点"图层：该GIS点图层标注了所有非平面交叉口的位置，包括立体交叉桥、下穿通道、桥梁、隧道、高架路等。此类图层是使用PST等软件开展考虑街道网络非平面性的网络分析的必要前提。