Hi, Scruss! 
My name is Yuliya, and I am the Quality Control Lead on the OSM team at Lyft.
We use our proprietary data sources, detailed at https://github.com/Test-DCT/OSM-LYFT-DCT/blob/1beae15649f43e0bef043fc0ef3950d7cbfdc867/osmtrainingmaterialsfeatures/Lyft-owned%20sources%20(ex.%20proprietary%20sources).md. Our organization maintains a comprehensive dataset of street-level imagery, which is considered proprietary and is not accessible to the general public. This allows us to make map changes more quickly, as our information can sometimes be more up-to-date than what's available in OSM. If source verification is needed in particular case, we can provide the imagery directly within changeset comments.
In this case, the turn lanes were added based on the June Lyft-owned street view imagery. However, the Bing satellite image shows the same information. Therefore, you may verify our changeset using Bing.

Best regards, Yuliya
