Megaregions are primarily located in well- developed countries with high levels of gross national income and in countries with overwhelming land area. According to the World Bank, the United States reports the highest gross national income in the world, while the U.S. ranks third in total land area behind Russia and Canada. Russia and Canada are large landmasses, but the formation of megaregions is expected to be hindered by their smaller total gross national income.
China ranks second in highest gross national income and ranks fourth in land area. The East Asia country has proactively planned and witnessed the growth of its Pearl River Delta and Yangtze River Delta megaregions with population counts near 120 million and 88 million people, respectively.
Other countries with large land area and GNI include Brazil and India. Brazil's megaregion stretchs from Rio de Janeiro to Sao Paolo and India's megaregion includes the cities of Dehli, Kolkata, and Dhaka. Many of the United States' megaregions are much smaller than the international megaregions mentioned above. However, future projections, such as those of America 2050, expect some U.S. megaregions to increase by 50% by 2025. Below are a few of the United States megaregions.
Texas Triangle MegaregionThe Texas Triangle is a United States' megaregion formed by the Houston, Dallas-Ft. Worth, and San Antonio metropolitan areas. The Texas Triangle is created by the highway system that links these cities together to form a triangle shape. This highway system is formed by three main thoroughfares of connectedness and includes interstate 10, interstate 45, and interstate 35. Interstate 10 connects San Antonio with Houston. Interstate 45 connects Houston with Dallas and Interstate 35 connects Dallas to San Antonio, while also traveling through the populous Austin metropolitan area.
The combined population of these major metropolitan areas totals about 16.5 million residents and that number is expected to increase by at least 50% in the next fifteen years. In addition to population, the Texas Triangle is considered a megaregion because of its gross domestic product per capita. The triangle has inherited a unique advantage in its economies of scale. The four economies of Houston, Dallas-Ft. Worth, Austin, and San Antonio interact spatially to mutually benefit through purchasing, financing, transporting, and shared technologies that reduce costs throughout markets across the geographical triangle.
Unlike many other megaregions, the cities that form the Texas Triangle are on the outskirts of an 'agricultural hinterland,' which is the area within the triangle where a significant amount of agricultural and natural resource production takes place. The production of natural resources and agriculture throughout the inner triangle are equally accessible to the markets that serve the surrounding cities. Some areas within the triangle are called micropolitan statistical areas, which include the towns of Corsicana, Huntsville, and Brehnam. In addition to transportation along highways, the triangle can also be loosely formed by the railroads that travel between the large metropolitan areas. The projected growth of people and business between these cities serve as evidence that this region will continue to develop into a centrally located region.
The Gulf Pipeline CorridorThe Gulf Pipeline Corridor is a projected United States megaregion formed between the metropolises of Houston and Beaumont, Texas, as well as Lake Charles, Baton Rouge, and New Orleans, Louisiana. The anticipated growth throughout the region is warranted by the projected employment trends throughout these Gulf Coast cities, which has been spurred by an increase in resource extraction throughout the area. The expected growth of jobs is expected to also bring unprecedented population influx to the region. Located within this region are the Port of South Louisiana and the Port of Houston that serve as two of the biggest ports in the United States. The combination of available land, ripe for building, and the increase in demands for energy resources, both domestic and international, will serve this region with the potential for densely populated growth.
Arizona Sun CorridorThe Arizona Sun Corridor is one of the fastest growing megaregions in the United States and has been fueled by extraordinary population and job growth throughout the late 20th and 21st centuries. The region is defined by its most populated city of Phoenix, which has been one of the fastest growing cities in the United States throughout the recent decades. The Phoenix Metropolitan Area includes nearly a dozen cities across two counties whose population accounts for well over two- thirds of the state of Arizona. Arizona's second largest city, Tucson, is roughly 100 miles south of Phoenix and constitutes the corridor's second largest city. Much of the region's growth is credited to decades of improved technologies that made the Sonoran Desert, and its' favorable climate, a comfortable living area. Increased growth is expected to be fueled by unique aspects to the region, such as an increase in solar technologies. The Regional Plan Association's program America 2050 predicts the Arizona Sun Corridor to double its population by the year 2040.
Southern California RegionThe Southern California Region is a densely populated region of California dominated by the Greater Los Angeles area, including San Bernardino County, and extending south through the San Diego metropolitan area. The combined populations of this region total more than 22 million people and are expected to increase with their ever-growing, diverse economy. The forecasted growth has prompted the California High-Speed Authority to propose plans to develop a high- speed rail that would travel from Los Angeles to San Diego, with stops throughout the Inland Empire. The construction of a high-speed rail in this region would bring the first of its kind to the United States. The region's sundry economy is a top-tier economy that has not missed a beat since the Gold Rush as it continues to funnel the commerce of information information technologies and the longevity of natural resources and agriculture.
Northeast RegionThe Northeast Region is a megaregion that extends across eleven states of the United States' eastern seaboard. It begins on the northern outskirts of Boston, Massachusetts, and travels south to the Nation's capital of Washington D.C. The region is home to roughly 50 million people who work to generate a fifth of the nation's gross domestic product. The largest metropolitan areas included in the region are the cities of Washington D.C., Baltimore, Philadelphia, New York City, and Boston. The corridor's rise to urbanization began with their historic establishments and city expansion was met with a transformation of infrastructure so that the cities could develop into interlinked hubs of people, information, and business. The region has historically been the site for some of the nation's largest cities and is expected to continue that trend into the future.
Unlike many megaregions across the United States, the Northeast Region is able to capitalize on existing public transportation methods that decrease the use of the automobile and allow for dense urbanization. The region has grown upon an extensive rail network, which has helped in allowing the region to achieve and maintain its appropriated carrying capacity. In addition to the availability of commuter rail, interstate highway 95 connects these cities as a means of automobile travel. The region's connectedness helps to improve its position as the financial capital of the world. The growth is attributable to the region's location for investment and capital, driven by domestic and international forces. The Northeast Region is also known as BosWash and was the first Megalopolis identified by French geographer Jean Gottmann.
For more information on megaregions, visit the America 2050 website, which includes maps and other information about America's eleven emerging megaregions.