An irrelevant non-zero. Over the last 5 years Uber added vastly more miles driven in congested areas which is the only important measurement in terms of increasing congestion. NYC traffic's average MPH is down and it's ride sharing's fault.

Lack of new Taxi medallions means it's not Taxi's fault. Their has been no increase in street level parking it can't make things worse. Uber on the other hand adds cars to the road above and beyond the limits of street level parking or even any parking which limits normal drivers.

PS: As you have not countered my argument I can only assume you countered the point that Uber is making congestion worse.