Seattle, Washington/Sidewalk Import
This import is in support of an initiative to jumpstart an OSM-based pedestrian network with global coverage. This proposal has been presented at the State of the Map US 2016 in Seattle, and the import strategy has been developed with feedback from the global OSM community, in addition to focused engagement with the local meetup chapter of OSM in Seattle. You can read more about our proposal on Proposed_features/sidewalk_schema.
Import Plan Outline
The goal is to improve mapping of the pedestrian network within Seattle by importing open sidewalk data from the City of Seattle's open data platform. The data is high quality and has coverage that would be extremely time-intensive to match through individual mapping.
The is currently a demonstrable need for this data: comparison of coverage of sidewalk data currently within the OpenStreetMap versus the coverage of data available through the City of Seattle shows a huge gap.
Taking advantage of this open data source will not only significantly improve the map with respect to coverage of sidewalk data, but also create the foundation for others to develop tools to assist those who would benefit from better sidewalk data, such as routing tools that are customized to the needs of the limited mobility community.
We plan to import pedestrian data, defined as: crossings, kerbcuts and sidewalks, within the bounds of the City of Seattle in order to address this deficit.
Our proposal includes delivering import tools to facilitate this import, and then working more directly with the community through activities such as mapathons, in order to get more people mapping and also meet human verification expectations.
- June 2016: scoping and analysis of import tool options - July 2016: development of import tools and presentation of strategy to the OSM community - August 2016: engagement with the community and import of data, including human verification community mapathons
We will be working with a sole data source for this import, sidewalk data which is published by the City of Seattle. The data
Provide links to your sources.
Data source site: https://data.seattle.gov/Transportation/SDOT-Sidewalks/dsed-gzpp
Data license: https://data.seattle.gov/data-policy
Type of license: Public Domain with Attribution
ODbL Compliance verified: yes
OSM Data Files
This is a one-time import that we hope will serve as a model for another urban areas. To this end, we actively encourage feedback not just on the proposal for the Seattle import, but also with respect to how our proposal may scale and be used by others.
The import will be semi-automated. We are developing import tools to bulk convert City of Seattle GeoJSON data into the OSM XML standard. We will be using an API through a customized version of the iD editor (see the HOT tasking manager for an example workflow) in order to integrate the data into the OSM database.
We will use this customized iD editor in order to include a human verification process to accompany the automated bulk conversion of data.
We will first convert the City of Seattle GeoJSON files to the proposed sidewalk schema standard, as outlined on Proposed_features/sidewalk_schema. As this schema falls within current conventions, this stage will ensure that source data maps to OSM tags.
We will need to convert the data into a schema that matches our proposed conventions for tagging pedestrian data, as presented at the State of the Map 2016 in Seattle, and also outlined on our wiki page proposal.
Once the data is within this schema, we need to convert it to the OSM XML standard. We are developing tools to allow us to do this.
Data Transformation Results
TBA We will link to prepared OSM files once produced.
Data Merge Workflow
We are working on this as a dedicated team as part of the Data Science for Social Good fellowship hosted by the University of Washington. We are currently a team of 8, with 4 students, 2 data science leads and 2 project leads. We are also working closely with the local OSM community in the City of Seattle, who we will directly involve in the human verification steps of data import. We are hosting our first mapathon to this end at the University of Washington on August 7th.
We are taking inspiration from other recent large imports, including:
Detail the steps you'll take during the actual import.
- Our workflow is as follows:
- Import the City of Seattle GeoJSON - Run scripts to convert the data to the proposed sidewalk schema - Run scripts to convert the output of this stage to the OSM XML - Upload the output to a customized tasking manager - Involve human verification and merge the output to the OSM layer through an API
- Our changeset size policy is to match census tract
- We take responsibility to revert any changes in case of breakages
Our conflation strategy is inspired by other recent large data imports, such as the LA building import.
Through using JOSM, we plan to have a strategy that is based around human verification. This will be a component of the tasking manager stage as previously described in our proposal.
The governing convention that we recommend is to favor superior coverage that is already present in the OSM layer.