You've heard of peer-to-peer housesharing via AirBnB. Maybe you've heard of peer-to-peer carsharing via companies like RelayRides and GetAround (you rent your car out to others when you are not using it). And you've heard of the cool PRT pods like the one being implemented at Heathrow airport by Ultra PRT (http://www.ultraglobalprt.com/wheres-it-used/heathrow-t5/. also see skycab.com).

And you've heard of good old-fashioned carpooling -- just giving a friend a ride.

What if we put them all together!

It would work like this:
-planners would figure out frequently used routes and stops in a neighborhood (maybe a 3 mile radius), similar to how they would plan the route for a RPT line. Likely stops would be local grocery stores, etc.
-people who want to participate would download an app for their smartphone. If you are driving, the app will show the route and stops.
-As you drive, if someone else needs a ride they open the app to flag a ride, and it shows you which stop they are at. You stop to pick them up and continue to the store.
-As a rider, you flag a ride and go to the hearest stop on the route, someone picks you up and you ride with them to the store.

This would require critical mass of usership in a neighborhood. But if enough people sign up, it would create easy, convenient mobility in the neighborhood and decreased congestion, without the huge upfront costs of building out a bunch of elevated lines for the PRT.

If you've ever looked around at all the cars with just a driver and 3 empty seats and wondered where they all going, this could help fill the seats and reduce the cars in your neighborhood, powered by neighborhood goodwill rather than government money.