[svs]

Carpooling has fundamental challenges that are perhaps impossible to overcome.

For one, dynamic routing for two or more people is always going to hurt the user experience. Imagine you're running late and your car re-routes to pick up another passenger - ugh!

Shared transportation for anything more than a neighbourhood trip should be professionally driven and to a schedule. That schedule can be dynamic as anything but must be solid and offer guarantees BEFORE the trip starts as to start point, route, etc.

Basically a very smart and discoverable bus.

[tmalsburg2]

In Germany, carpooling has been a mainstream thing since the mid-90ies or perhaps even earlier. The majority of trips are long-distance, i.e across-country. You are right that carpooling has has some shortcomings but it's so ridiculously cheap that many people happily accept those shortcomings. I used it many times when I was a student and 90% of the trips went as planned.

[mjmahone17]

On the other hand, for commutes from, say, SF to Mountain View, or Mesa to Scottsdale, I bet a lot of drivers would love to have an extra passenger so they could use the HOV lane. During rush hour, the difference between being able to use the HOV lane vs. not could easily be 30 minutes.