Corridor Classification Methodology
MAFC researchers used a combination of data sources to analyze, identify, and characterize the nationally significant highway freight corridors in the region.
The analysis was an iterative process that included input, reviews, and feedback from the MAFC state representatives. This analysis also evolved as MAP-21 freight initiatives became clearer and better understood.
The corridor classification scheme used in the MAFC Regional Freight study was initially modeled after the methodology used by the FHWA to identify major freight corridors in Freight Story 2008, and then fine-tuned to the thresholds to observances in the MAFC states with a focus on roadways. This functional classification scheme is meant to take into account the nature of freight movement across the MAFC region and as it is connected across the country. Corridors in the MAFC Regional Freight Study are classified as Tier 1, Tier 2, and emerging.
- Interstates or roads with average daily truck traffic greater than or equal to 8,500 and connecting cities of 1 million or more;
- OR, Interstates with connections to international gateways and average daily truck traffic greater than or equal to 3,000;
- OR, Interstates or roads with average daily truck traffic greater than or equal to 8,500 and connections to major intermodal terminals;
- OR, Interstates with 30 percent or more trucks;
- OR, major NAFTA-related congressionally designated high priority corridors.
- Interstates or roads with average daily truck traffic greater than or equal to 4,000, and may connect smaller metropolitan areas.
- Interstates or roads contained within a single state with an average daily truck traffic greater than or equal to 4,000, or truck percentage greater than or equal to 20 percent;
- OR; Interstates or roads with truck percentage greater than or equal to 25 percent, and connecting at least one rural area (low population density);
- OR, low-volume interstates or highways with average daily truck traffic greater than or equal to 3,000;
- OR, newly constructed interstates.
- Includes urban interstates, freeways, and expressways with average daily truck traffic greater than or equal to 4,000 for 75 percent of the route.
Under this categorization scheme, the regional freight study identifies a nationally significant corridor network that consists of Tier 1 and Tier 2 corridors, national connectors, and emerging corridors. The corridors classified as national collectors can be thought of as hubs or nodal connectors (origins and destinations), while the Tier 1, Tier 2, and emerging corridors can be considered different types of spokes based on volume and network connections.
The MAFC Nationally Significant Corridor Network identifies and characterizes the most significant freight corridors across the region. As the MAP-21 national freight network is defined and assessed, the MAFC network corridors and their characterizations can be used to advance and advocate for the inclusion of these corridors in additional mileage identified for the national freight network. The MAFC network also provides state practitioners and planners with the information and background needed to make the freight connections across states lines. This multistate collaboration and connectivity is expected to increase in importance as multi-state freight projects are advanced in policy and program initiatives.
A number of the sections provided for the corridors, from mileage, volume, presence of freight generators, freight facilities (ports, airports, intermodal connectors, and truck parking), and metropolitan area economic profiles among others, can be traced back to the MAP-21 criteria identified as important to the designation of a Primary Freight Network. These measurable and objective factors provide for comparison and advocacy to support states in their identification of corridors to include in future freight initiatives and policy developments.