Getting to this granular level is imperative if companies are to understand the travel environment today, and set policies accordingly. Many companies use travel expense software from Concur, Certify, SAP, and others to automate expense management already. But they need to dig deeper. An organization might not have set a baggage fee limit in the past, for example. But with insight into how much it costs to check luggage, or go over a certain weight nowadays, policies might now be needed. Or finance teams might have to readjust budgets to account for these fees. If a majority of your employees travel, and spend $100 or more for ancillary fees for each trip on certain airlines, you'll certainly see a long-term impact on the travel budget. It also might determine which carriers you favor for employee travel -- knowing the base airfare is no longer enough.

Finance managers have to look at the big picture to avoid getting a skewed perception of travel costs. If you simply lumped all of those fees into a single category, you wouldn't extract the same intelligence. The devil of travel is certainly in the details these days.