How UPS gets 750 million packages from warehouse to doorstep this season

Technology has made it easier than ever to buy gifts online and track the spoils of your spending spree as they make their way from retailers' warehouses to your doorstep in time for the holidays.

But for all the talk of packages being delivered by drones, this year's record-setting online sales still depend on humans to handle the last leg of the journey - people like Dave Knudsen, who will spend the final days of the year battling traffic and unpredictable Chicago weather, speed-walking up and down driveways and across lawns while lugging packages light and heavy.

A United Parcel Service driver for more than three decades, Knudsen, 54, of St. Charles, Ill., will