Hello, I am responding here as requested by @SomeoneElse in the comments section of the MapRoulette Challenge “London - Conflicting ML Sidewalk Tags” (now renamed: “London - Update Highway Sidewalk Tags”).
This challenge identifies highways with sidewalk tags that conflict with the apparent sidewalks as viewed by mappers looking at satellite imagery. Our team manually reviews the satellite imagery and determines if the tags on each highway are consistent with the visible sidewalks near the highway. This process involves a mapper using a tool to confirm or flag each highway’s sidewalk tags. The information is then processed to create a MapRoulette challenge that instructs users to review each flagged highway and determine the correct sidewalk tags to apply to the highway feature.
We use MapRoulette because it provides a platform for processing the flagged highways one at a time, allowing mappers to inspect each one and make the appropriate changes if necessary.
In response to questions posed in the challenge comments:
Q: Where was this discussed with the local community?
A: We did not widely discuss this specific challenge with the community, as we did not believe it required local community notification.
Q: What mechanism was used to “detect” missing data?
A: As mentioned above, this was a manual process where humans reviewed one highway at a time and confirmed or flagged the presence of sidewalks on one or both sides.
Q: How old was the data used for the analysis?
A: All imagery for London is from 2022.
I realized that the name of the challenge was misleading and incorrectly implied that we use machine learning to derive tasks, so I changed the title
to “London - Update Highway Sidewalk Tags” and added more accurate information about how the data was gathered to the description. Additionally, I noticed that this challenge is a “tag fix” challenge that suggests a possible solution to each task in the challenge. This was done to help mappers fix the tags consistently and reduce possible typos. If these suggestions are too often inaccurate then we can disable them - or if specific mappers would prefer not to see the suggested changes they can be turned off in the MapRoulette settings.