Bandwagon, based in NY, has been doing this kind of ridesharing. They pointed out that Uber/Lyft's 'ridesharing' model wasn't really ridesharing (now it kinda is). See https://medium.com/@HiBandwagon

and they work on taxi lines at airports, events: http://blog.bandwagon.io/post/92569728340/meet-the-hop-lane-...