I think it'd be hard to actually quantify the impact. Chicago's also constantly under construction, the downtown area has had major bus route redesigns with the "JUMP" routes, and that's caused a lot of congestion too.

I'm not really familiar with new york's streets, but ours have been over capacity forever and now with uber/lyft there's a lot more single passenger car traffic in the business areas. Much more so than cabs, because getting them is much more convenient than cabs ever were here - calling a cab in chicago is a joke, honestly, and if you weren't in an area they pass by frequently you were out of luck. I feel like more people choose the uber option for short trips that would have been transit in the past. The convenience of it is the model, after all.