I think B39 is a good example of an improvement most affected by the congestion pricing. It's a very short route, with very few stops, and the principal part of the route being the Williamsburg bridge. The rest of both Brooklyn and Manhattan traffic affects it rather little.

I think that "cherry-picking" is when you find outliers and show them off pretending they are typical examples. What I would call this is maybe a "poster child": a specially chosen example where the result is most dramatic and clearly seen.