Besides all the great points others have made, the origin and destination of the shared riders don't need to be the same, they just have to share some common se

Besides all the great points others have made, the origin and destination of the shared riders don't need to be the same, they just have to share some common segment. Furthermore, although there is time lost waiting for the other rider to be picked up or dropped off, there is also time gained by not having to find parking and then walk from the car to your destination, since the shared car can drop you off right out front.