Lets talk about the roles and perspective of each of the participants.
Shippers… they want the good picked up and delivered at specified times, with a predictable transit time, and zero loss or damaged items. At of course, the lowest price.
The Carrier… wants to make as much money as possible by minimizing revenue and lowering operating costs.
Agents (I have grouped them with Carriers until now)… they just match carriers and customers.
Government… historically the government regulated carriers dictating the price they could charge. Now the government is in charge of a transportation service (USPS), but they are also in charge of the transportation safety which drive current regulations (we will talk about these later).
The last role is the public… They are concerned with transportation safety, expense, accessibility, congestion, and environmental impacts.