Ward aggregated PTAL stats 2023

Public Transport Accessibility Levels (PTAL) are aggregated at the Ward level, a standard geographical unit in the UK. This dataset includes summary statistics (min, max, and mean PTAL scores) per Ward. The aggregation is based on Access Index values of PTAL (Public Transport Accessibility Level) dataset. PTAL dataset measures accessibility to public transport services across Greater London using a 100m x 100m grid resolution. PTAL scores are derived from walking times to nearby public transport services and service frequencies. This granular dataset is aggregated to the Ward level. The mean of PTAL is calculated based on access indices of grid centroids within each Ward and classified into six PTAL categories again. Similarly, the minimum and maximum values are identified using grid centroids within each Ward. The spatial boundary layer displaying Wards on the map sourced from Office for National Statistics licensed under the Open Government Licence v.3.0.公共交通可达性等级（Public Transport Accessibility Level, PTAL）以英国标准地理单元——教区分区（Ward）为聚合单位。本数据集涵盖各教区分区的汇总统计指标，即PTAL得分的最小值、最大值与平均值，本次聚合基于PTAL数据集的可达性指数（Access Index）值。PTAL数据集以100米×100米的网格分辨率，对大伦敦全域的公共交通服务可达性进行测算，其得分由前往周边公共交通站点的步行时长以及线路班次频率推导得出。该精细粒度数据集被聚合至教区分区级别：PTAL平均值的计算基于各教区分区内网格质心的可达性指数，并再次被划分为六大PTAL类别；同理，各教区分区的PTAL得分最小值与最大值通过其内部的网格质心确定。本数据集所用的展示教区分区的地图空间边界图层源自英国国家统计局（Office for National Statistics），并依据《开放政府许可协议v3.0》（Open Government Licence v.3.0）获得授权使用。