An anonymous reader quotes a report from Recode: Uber is beginning to roll out a cheaper version of its ride-sharing UberPool service, called Express Pool. The service, which was being tested in Boston and San Francisco, is now available in Los Angeles, San Diego and Denver, and will launch in Miami, Philadelphia and Washington, D.C., tomorrow. The idea is that Express Pool, which requires riders to walk a little to meet their driver -- and then again to their destination after being dropped off -- will make shared rides more efficient. If it works, it should both increase the number of rides that drivers can give and also make those shared trips faster for passengers. The new service tests a thesis Uber has long had: Lower prices means higher utilization, and higher utilization means more money -- both for drivers and for Uber. Also that road congestion is bad and the solution is to share more rides. Those are the same theories that sparked the creation of the original UberPool service, which requires a little less walking. But the hope is that this will make it easier to match more passengers and therefore lose less money on each shared ride.