Snopes says this is real but “miscaptioned”:

https://www.snopes.com/fact-check/china-50-lane-highway-traffic-jam/

This is a genuine photograph of a traffic jam in China. However, the caption frequently attached to this image is a bit misleading.

This photograph was taken in October 2015 at the end of Golden Week, a week-long national holiday in China, and it captures heavy congestion at a toll gate on the G4 Beijing-Hong Kong-Macau Expressway

…

While this highway may expand to about 50 lanes at this toll booth — we counted the number of approximate car widths on a higher resolution version of this image and found that the “50-lane wide” expression was generally accurate for this portion of the road — the G4 expressway is not a “50-lane highway.”

I mean that’s clearly just a toll plaza, right? Not actually a 50-lane highway, that then drops down to 4. Also that’s not 50, looks closer to 25-30 toll lanes.