UPS is the largest delivery company on the planet, flying more than 500 jets in a mission to serve a customer base that topped 8 million last year.
Operating at a similar scale is the U.S. Postal Service, which delivered 154 billion pieces of mail in 2015 using 215,000 vehicles. At that scale, the postal service is one of the largest civilian fleets in the world.
Despite the enormity of their infrastructures and logistical smarts, UPS and the Postal Service haven’t been able to overcome one long-standing obstacle: the last mile from distribution center to doorstep.