Hestia SW-IFL Onroad Fossil Fuel Carbon Dioxide (FFCO2) product: Road segment-level annual FFCO2 emissions across Arizona (2017-2022), version 1.1

The SW-IFL onroad fossil fuel carbon dioxide (FFCO2) emissions data product represents CO2 emissions from the combustion of fossil fuels by motor vehicles (e.g., passenger cars, trucks, buses, motorcycles) traveling on designated roadways. The emissions are represented geographically on each road segment within the state of Arizona spanning the 2017 to 2022 time period. This data product was developed as part of the Southwest Urban Corridor Integrated Field Laboratory (SW-IFL) project, which aims to provide new knowledge and tools that address urban environmental issues by integrating high-resolution observations, modeling, and civic engagement. The emissions data are provided in CSV (input data, ONR_FFCO2_AZ_county.csv) and GeoPackage form (output polyline objects - about 786,000 road segments, XXXX_AZ_v1.1.gpkg) designated by road class (interstates, arterials, collectors, local). The metadata file (Metadata_SW-IFL_Onroad_annualFFCO2_v1.1.docx) provides details about attributes and data formats. The GeoPackage emissions data are provided separately for local roads and nonlocal roads (interstates, arterials, collectors). The method file (Methods_SW-IFL_Onroad_annualFFCO2_v1.1.docx) describes the data processing flow and data sources. Update on 2024-04-17: Updates were made to both the input emission data file (.csv) and output segment-level emission file (.gpkg). There was an update in county-level emission input data (ONR_FFCO2_AZ_county.csv) and the entire road segments were reprocessed to reflect this update.Update on 2024-04-29: Update was made to one output segment-level emission file (Nonlocal_AZ_v1.0.gpkg). There was an error in the AADT values and the data were reprocessed to reflect this update.Update on 2024-10-22: Temporal coverage was extended to include 2022. VMT values were recalculated using new AADT data and the entire road segments were reprocessed to reflect these updates.

SW-IFL道路化石燃料二氧化碳（FFCO2）排放数据集产品，涵盖指定道路上行驶的机动车（包括乘用车、货车、巴士、摩托车）燃烧化石燃料所产生的二氧化碳排放。该排放数据以地理空间形式映射至亚利桑那州内的各道路路段，时间覆盖2017年至2022年。
本数据集产品是西南城市走廊综合野外实验室（Southwest Urban Corridor Integrated Field Laboratory，SW-IFL）项目的组成部分，该项目旨在通过整合高分辨率观测、建模与公众参与，为解决城市环境问题提供全新的认知与工具。
该排放数据提供两种格式：逗号分隔值（Comma-Separated Values，CSV）格式（输入数据文件：ONR_FFCO2_AZ_county.csv）与GeoPackage格式（输出折线对象——约78.6万个道路路段，命名格式为XXXX_AZ_v1.1.gpkg），数据按道路等级分类，包括州际公路（interstates）、干线道路（arterials）、集散道路（collectors）与社区道路（local）。
元数据文件（Metadata_SW-IFL_Onroad_annualFFCO2_v1.1.docx）详细说明了数据集的属性与数据格式。GeoPackage格式的排放数据按社区道路与非社区道路（州际公路、干线道路、集散道路）分别提供。
方法文件（Methods_SW-IFL_Onroad_annualFFCO2_v1.1.docx）阐述了数据处理流程与数据来源。
2024年4月17日更新：本次更新覆盖输入排放数据文件（CSV格式）与输出路段级排放文件（GeoPackage格式）。其中县级排放输入数据（ONR_FFCO2_AZ_county.csv）完成更新，并重新处理了全部道路路段以适配此次更新。
2024年4月29日更新：对一份输出路段级排放文件（Nonlocal_AZ_v1.0.gpkg）进行了更新。原数据的年平均日交通量（Annual Average Daily Traffic, AADT）存在错误，因此重新处理了数据以修正该问题。
2024年10月22日更新：将时间覆盖范围扩展至2022年。利用新的AADT数据重新计算了车辆行驶里程（Vehicle Miles Traveled, VMT），并重新处理了全部道路路段以适配此次更新。