Although the team has shared the process in depth at various conferences and discussion post and the wiki, we have gotten feedback that we could clear up some of the processes by providing more details. So here it is.

At Facebook, we use our ML (machine learned) data as a starting point but then completely re-edit, fill in the gaps, and correct errors with human editing. Machine learning can do amazing things, but even the best predicted area will always have issues that need a human to fix. An untouched ML file will often have disconnected ways, gaps in the network, road type inconsistencies, and geometry issues. The job of our human editors is to use this ML data as a base and build fully fleshed out, high quality data.

The Machine Learned XML file

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