One promise of ride-hailing companies like Uber and Lyft was fewer cars clogging city streets. But studies suggest the opposite: that ride-hailing companies are pulling riders off buses, subways, bicycles and their own feet and putting them in cars instead...

The latest variation of an Uber ride will require a short walk.In eight U.S. cities, the ride-hailing company is rolling out a service called Express Pool, which links riders in the same area who want to travel to similar destinations...