INTERSTATE-22 (CORRIDOR X)
Conceived as part of the Appalachian Development Highway System to bring mobility and economic development to underserved areas of the region, the Corridor X project comprised some of the largest roadway projects in the history of the state totaling over $1 billion in design and construction. Now officially Interstate 22, it travels through 96.5 miles delivering interstate mobility and growth to emergent northwest Alabama communities.
This part of the state was included in the initiatives of the Appalachian Regional Commission, formed by Congress in 1965 to bring economic development to and improve quality of life in the region. However, it was not until 1983 that initial construction began on the Alabama portion of Corridor X. Finally, with its designation as a High Priority Corridor in 1995, funding, design, and construction accelerated, with most of the route completed between 2001 and 2007. In 2004, Corridor X was officially designated as “Future I-22.”
The segments running through Marion and Walker counties presented geotechnical and right of way challenges, including rock and coal deposits not common in other parts of the state. This required mineral right transfers and the fill of over 200 feet in some areas to build up the area enough to support the interstate infrastructure, which included a total of 29 new or widened bridges. This project entailed coordination for six active railroad lines, urban residential neighborhoods, utility coordination and environmental compliance.
Engineering challenges in developing the corridor also included geometric complexity and environmental sensitivity, as well as preliminary and final designs for numerous roadway and bridge improvements, diamond and cloverleaf interchanges, and ties to existing surface streets. Detailed traffic analyses determined lane requirements for mainlines, ramps, and cross streets, and necessitated right-of-way survey and mapping for more than 260 tracts. The project also required acquisition of 1,164 tracts of property over a 25-year period.
Through the diligence and perseverance of the state’s lawmakers and transportation officials, the decades-long effort culminated in the completion of the project in 2016. Several generations of civil, structural, electrical, drainage, utility, and traffic engineers as well as heavy construction contractors, road builders and environmental specialists contributed to its ultimate completion.
The final five-mile segment and four-level interchange at Interstate 65, the eastern terminus, constituted the largest single project to-date in the history of the Alabama Department of Transportation with a project value of $300 million. This complex interchange has four levels and multiple bridges as well as a high average daily traffic. Five sets of bridge plans were developed consisting of 24 bridges, nine of which were on a curved alignment.
Together with segments in neighboring states, the completed corridor links Birmingham to Memphis, Tennessee, and fills a gap in the Interstate Highway System facilitating freeway passage from Atlanta, Georgia, to Oklahoma City, Oklahoma. I-22 provides access to major cities, employment opportunities and the transport of goods and services for the northwest portion of Alabama that previously had no means of connectivity to these services. Economic development has followed the completion of I-22, exemplified by the announcement of the $100 million Yorozu auto parts plant in Jasper.