Interestingly, this was how Lyft started (as a company called Zimride). That concept didn't take off and the Lyft one did, so they shuttered this a long time ago. They've come full circle.
Actually zimride got sold to enterprise. Maybe they needed to build out the two-sides of the marketplace before being able to actually do "ride-sharing"
When I moved from Portland, OR to Los Angeles, CA I sold the extra seat in the Penseke truck on Zim Ride.