The concept of carpooling to work isn't new. But the way we carpool has changed dramatically through ridehailing apps like Uber and Lyft. While carpooling may seem like a green way to commute, it is actually increasing congestion and emissions. Uber and Lyft released a joint report last month showing that their services have contributed to an increase in vehicle miles traveled in cities, by up to 13 percent. We spoke to Sarah Kaufman, Associate Director of the NYU Rudin Center for Transportation.