I'm not sure if Uber/Lyft put more cars on the road, but I'm sure that Uber and Lyft drivers do things that cause traffic. Many analyses of traffic have shown

I'm not sure if Uber/Lyft put more cars on the road, but I'm sure that Uber and Lyft drivers do things that cause traffic. Many analyses of traffic have shown that individual drivers can cause huge downstream traffic effects. When you see an Uber driver just stop at a corner at a major intersection, there can be 10-15 cars slowed by having to wait or go around. Biking around SF has made me very wary of certain car models popular for Uber. If I see a Prius I assume it could stop anywhere at any time. Even with all that ... These services may still be a net positive. I use them a lot on the weekends and would never be able to get around the city like I do without them.