Hourly Volumes 2021

Tabular data containing 2021 hourly traffic counts from continuous and program count stations in the District of Columbia, Maryland, and Virginia that are provided to TPB by the respective state DOTs. The hourly counts are processed, listed by direction, and also matched to the appropriate directional network link. Separate traffic volume tables are provided for each state. The tables are in CSV format. This tabular data can be joined to the Count Stations layer (point) by the StationID field. The data also contains the field ABPair that refers to the network link which is associated with the count station in order to be used in the network modeling process. The latest network link layer can be found here. Note that network layers are year-specific; ABPair on historical hourly volume tables may not match the ABPair on the current network link dataset. In cases where a count station is associated with more than one network link, the volume tables will contain one record for each link for each hour. This situation occurs where nearby stations are used for counts on screenline links and also in areas where one set of high occupancy vehicle (HOV) links is associated with multiple sets of low occupancy vehicle (LOV) links. This is important to note, so that counts in the volume tables are not summed which would result in double counting.该表格数据包含美国哥伦比亚特区、马里兰州及弗吉尼亚州境内连续式计数站与规划式计数站在2021年的小时交通流量统计数据，上述数据由各州交通部（Department of Transportation, DOT）提供给TPB。小时流量统计数据已经过预处理，按通行方向分列，并与对应的定向网络链路（network link）完成匹配。各州均提供独立的交通流量表格，数据格式为逗号分隔值（Comma-Separated Values, CSV）。可通过站点ID（StationID）字段将该表格数据与点状计数站图层（Count Stations layer）进行关联连接。该数据集还包含ABPair字段，该字段指向与计数站关联的网络链路，可用于网络建模（network modeling）流程。最新的网络链路图层可在此处获取。请注意，网络图层具有年份特异性；历史小时流量表格中的ABPair字段值可能与当前网络链路数据集中的ABPair字段值不匹配。当一个计数站关联多条网络链路时，流量表格将为每小时的每条链路生成一条记录。这种情况常见于以下场景：使用邻近站点对屏幕线链路（screenline links）进行流量统计，以及当一条高占用车辆（High Occupancy Vehicle, HOV）链路关联多条低占用车辆（Low Occupancy Vehicle, LOV）链路的区域。此细节需特别留意，切勿对流量表格中的统计数据直接求和，否则将导致重复计数。