The Missing Links: Reconnecting ‘America’s Heartland’

The United States has built one of the world’s most extensive transportation networks. Every year, the United States generates around 8 billion domestic inter-city trips of more than 115 miles (180 kilometers), and 6 billion of those journeys are under 460 miles (750 kilometers).  

Yet, over the past two decades, regional air connectivity in the United States has steadily contracted. Airlines have increasingly concentrated operations around large hubs, while hundreds of shorter regional routes have disappeared. 

Since 2000, more than 800 regional air routes have closed across the country. Routes under 350 miles (550 kilometers) have seen particularly sharp declines, falling by almost 80%. 

Several factors have contributed to this trend, including airline consolidation and the increased use of aircraft designed for longer routes. 

The reduction in regional connectivity has had consequences far beyond the aviation industry. For many communities, each route dropped has meant direct access to neighboring economic centers has become more limited. What we see is not a drop in travel altogether following the closing of a route, but a mode shift from air to ground, with travelers consequently turning to cars or buses. This suggests that demand has not disappeared: with the right aircraft and the right economics, many of these lost regional links could be viably restored, and new connections could be created. 

‘America’s Heartland’: A Region Hiding in Plain Sight 

To better understand travel patterns between regions, ATR developed MobilityMonitor, a new analytical approach that maps real inter-city travel flows using anonymised mobile data. Rather than looking only at existing airline traffic, it reveals how people move across regions and where demand exists, independently of the mode of travel. 

ATR’s MobilityMonitor highlights a concentration of demand across a group of 15 cities stretching from the Great Lakes down to the Gulf Coast and from the Mississippi River eastward to North and South Carolina, Virginia, and Pennsylvania. 

Far from being peripheral, cities such as Pittsburgh, Memphis and Milwaukee, are major economic, educational and cultural centers. They are home to globally recognized companies and industries that shape everyday life across the United States. From Oreo cookies and Wendy’s restaurants to Harley-Davidson motorcycles, Mercedes-Benz vehicles and aerospace technologies developed for NASA missions, these cities contribute far more to the national economy than the attention often given to their regional connectivity needs would suggest. 

Because of their geographic position, as well as their cultural and economic significance, we refer to this region as ‘America’s Heartland’.  

What these 15 cities have in common is that they are not served by large hub airports, according to the FAA NPIAS definition. Most are classified as medium-sized hubs, despite serving dynamic metropolitan areas with strong economic fundamentals. Over the past two decades, as airlines consolidated operations around large hubs and prioritized larger aircraft on longer routes, many direct regional air connections serving these communities disappeared, and many travelers started travelling by car. Despite these cities generating over 1 billion regional trips per year and playing a critical role in the U.S. economy, their air connections to other cities are much less convenient than for cities with large hubs.  

The Mobility Gap 

While the United States’ air transport system is highly efficient at connecting travelers through large hubs, it is less effective at serving the mobility needs of travelers to and from medium and small-size cities. 

Our analysis shows that around 90% of domestic air passengers pass through a large hub airport during their journey. Yet only half of all mobility flows across all modes are linked to these cities. The other half connects medium-sized cities and smaller communities, many of which have seen direct air services disappear over the past two decades.

As a result, millions of travelers who could benefit from air transport continue to rely on long drives or indirect itineraries. This disconnect between mobility demand and air service availability creates a ‘mobility gap’. Passengers departing from these 15 focus cities often face journeys that are three times longer than what they would have with a direct flight. 

Ultimately, the decline of regional routes extends beyond an aviation industry concern. It directly affects travelers, increasing journey times, reducing convenience and making air transport less competitive against driving. 

For regional airlines, it represents one of the most significant untapped opportunities in the U.S. market.  

Turboprops are built for regional mobility 

Connecting these communities requires an aircraft that can make regional routes economically viable. ‘America’s Heartland’ doesn’t need larger aircraft. It needs the right aircraft.  

For regional routes under 460 miles, turboprops offer the ideal combination of economics, efficiency and performance. They deliver up to 45% lower fuel burn, CO₂ emissions, and Cash Operating Cost per trip than a similar-sized regional jet. Each turboprop deployed can be expected to generate around US$2M additional profit per year.  

ATR estimates total U.S. demand at around 300 turboprops. The first 100 aircraft will support traffic growth by attracting passengers from ground transportation to air travel.  

The next 100 aircraft will help airlines optimize and sustain their existing fleets. ATR does not seek to replace all regional jets, but to complement them. As regional jets age and approach retirement, many could be redeployed to longer sectors that are better aligned with their design characteristics. Operating fewer short flights would also reduce their exposure to take-off and landing cycles, helping extend their service life. 

The final 100 aircraft will unlock new direct connections. Many city pairs already generate significant indirect traffic, demonstrating existing demand for air travel. Introducing direct services on these routes could reduce journey times to as little as one-third of what they are today while improving connectivity for regional communities. 

Overall, these 300 aircraft represent three complementary opportunities: grow the market, strengthen existing operations and open new routes. Together, they would help airlines build more efficient and sustainable networks while delivering better connectivity and a more convenient travel experience for passengers.