The U.S. Postal Service has selected six companies as finalists to build prototypes for a next-generation mail delivery vehicle. Hybrid drivetrain and new-age technologies are among the top priorities for the new vehicle. The six companies were awarded contracts worth a total of $37.4 million to produce 50 prototypes. This is only the latest development in the USPS’ quest to an updated fleet, which started in earnest in January 2015.