"If you build it, they will come." That famous movie quote might apply to an athletic field more than an airport these days. While many large commercial airports operate at or near full capacity, some nearby airports lie practically abandoned. Are they the answer to our air traffic congestion problems?

Two interesting conversations are going on. One deals with the need to ease congestion at busy airports around the world; the other laments the proliferation of underused, overhyped airports that sit waiting for some significant form of air traffic. Some aviation experts believe that the latter could be the solution to the former, but this may be easier said than done. The concept is called wayports -- major airports built away from densely populated areas that act as intermodal hubs where air, rail and motor transport users are funneled through to their destinations. The concept has actually been discussed in the United States for decades and could have been in the heads of designers and planners when airports like Dallas-Ft. Worth International and Denver International were built. The goal of wayports is to alleviate traffic at congested airports by drawing more connecting passengers and letting the big-city airports enjoy more of the origin and destination (O&D) traffic. Major cargo airlines already operate in this manner, avoiding heavily congested airports and conducting their cargo transfers at large airports away from big cities.

The claim of wayport proponents is that connecting passengers probably don't really care as much about where they connect as they do about making their connections on time and without hassles. Airports located away from crowded regions could form a network of reliever airports that keep connecting traffic moving even when weather causes disruptions over the congested airspace of big-city airports. But can the concept be that simple? Can airlines simply "shift" their hubs when the weather gets bad or will this require massive operational changes to establish their connecting hubs primarily at wayports? One U.S. airport that lived its life as a large hub for U.S Airways now sees the wayport concept as a way to survive.

Pittsburgh International claims that only 15 percent of its capacity is being utilized since U.S. Airways dismantled its hub there in the early 2000s. The airport is large, modern and well equipped to handle many aircraft takeoffs and landings per hour, even when the weather is poor. The airport's proximity to Philadelphia International and the three major New York/New Jersey area airports makes it an ideal test case for the wayport concept. In a white paper dated February 2011, the Allegheny County Airport Authority made its case for becoming a reliever hub for the area's congested airports. The argument was that it would cost far less to test and implement such a model than to continue pouring money into expanding capacity at overstressed airports. Are there more "Pittsburghs" out in the aviation world? Apparently there may be more than you think.

Around the world, shiny new airports have been built, typically during better economic times, but now sit nearly idle. Spain has seen four such airports built in recent years -- the Castellon International Airport, Ciudad Real's Central Airport (boasted as a reliever airport for Madrid-Barajas Airport), Huesca airport in northern Spain, and a second airport for southern Murcia which sits 30 minutes from the original one. The reasons for building these are numerous but they have largely been seen as wasteful, political crown jewels for local municipalities and their leaders. But Spain is not alone.

With oversized runways beckoning like outstretched arms, airports once hailed as the drivers of economic health through aviation (Montreal's Mirabel comes to mind) now play different roles, and some play no role at all. The relatively small land mass we know as South Korea has built several airports that some critics argue are too close together and unnecessary. These airports are also competing with the emergence of high-speed rail. The most infamous of these airports is Yangyang International on South Korea's east coast. But the story repeats itself elsewhere. There are even satellite images of entirely empty "ghost" cities in China which have become popular on the internet.

Given the predicted growth of air travel over the next several decades, could there be a future for today's neglected airports after all? As wayports, reliever airports or facilities yet to be determined, will the questionable investments of today finally bear fruit, albeit many years later?