A User that has the Role of 'Driver' has the Home Terminal option set. The available Home Terminal list is populated by the Memberships assigned to the User. 

To change a Driver's Home Terminal:

From the Home Terminal list select an Organization (OU)

To add a Home Terminal:

Add a Membership for another OU. The Home Terminal list will now have the option to select the newly added OU.

Note: if the OU you're looking for isn't available in the Membership list of Organizations, you can add a new OU by going to 'Management & Settings' > Organizations.