Our solution is an app, with complex backend system, which helps you automate the process of ride-sharing. The basic idea is that the driver would not need to do extra detours, just stop along the way to pick and drop passengers.
This would help to increase the occupancy of vehicles, and reduce the need to drive a car yourself, since the probability to get to your destination fast enough is very high.
It is also a very useful way to complement other transport means to save the "last-mile" problem.
The system will probably include incentives, so the passenger will need to pay something, and the driver will receive it, but it will still be much cheaper than other means of transport.