TRAVERSE CITY -- With two weeks left until Christmas, it’s the busiest time of year for the shipping business. The icy roads are proving to be an added challenge for carriers.

Monday is expected to the be busiest 24 hours in company history for Federal Express. As many as 16 million packages will be processed through their system. That is double the volume of a normal day and a 12% increase in deliveries from last year. Boxes are also stacking up and are ready to be shipped out at UPS.

UPS Business Manager, Jason Gauthier says, "Today is one of the busiest days of the year; pickup wise as well as delivery."

With icy roads and blowing snow causing poor visibility, it is making getting those packages to homes both dangerous and difficult for drivers.

Gauthier says, “Drivers are having problems getting in to places that normally they wouldn't. Roads are closed and plows haven't had a chance to get to a lot of side roads which is where we deliver a lot of packages."

The United States Post Office in Traverse City called in substitute drivers for some extra help on routes.

Substitute Carrier David Gibson says, “This gets to be the heaviest time of year. We try to help each other out the best we can. I'm doing part of somebody's route and then I’m going to come back and take parcels to help somebody else out too."

All of these drivers say it helps them when driveways are cleared off and the space around the mailbox is shoveled. They also ask that you give them space as they drive down the road.