The I-75 South corridor is one of the busiest, most vital transportation corridors in Georgia and provides key connections within and outside the state. This corridor directly connects the Atlanta region and the Macon region in central Georgia and also serves the Georgia coast and Port of Savannah. Ensuring the continued safe and efficient travel within this corridor is critical to economic vitality.
The Georgia Department of Transportation has been conducting a master plan and subarea study of I-75 from south of the Hartsfield-Jackson Atlanta International Airport to south of Macon. The study will form the policy blueprint and proposed course of action for future transportation system improvements of the corridor through the year 2040.
Closely coordinated with local and regional stakeholders, the study identified local and regional land-use policies to protect the multimodal transportation mobility and satisfactory system operations. The study helped to target public investments to support private-sector economic development initiatives and freight movement within the corridor and to adjacent areas.
Integrated Corridor 'Freight' Planning (ICFP)
The concept of integrated corridor "freight" planning (ICFP) was developed for the I-75 South study as a process for assessing existing and future transportation deficiencies. The assessments are based upon several factors, including isolated congestion, rapidly changing land uses in areas set aside for light industrial/freight and logistics, economic development goals and initiatives, and strategic development and prioritization of improvements.
The ICFP process incorporates these elements and strategically targets freight infrastructure development using a prioritization system fully coordinated with the state and local policy framework and identified goals. The process involves four steps that integrate transportation with land use:
- Identify potential freight hotspots
- Identify existing and/or future deficiencies
- Assess truck freight routing, and
- Develop recommendations supporting and enhancing the existing and future freight network.
Step 1: Identify Potential Freight Hotspots
The first step in the process involved collecting, organizing, combining and assessing existing and future land-use data for the jurisdictions within the corridor using a Geographic Information System (GIS). The parcel areas of existing and future industrial use, or those uses that would generate heavy truck traffic were then identified and separated from the other nonfreight intensive uses.
After identifying the industrial and freight-related parcel areas, the buildable areas of each parcel were estimated. Using those numbers and applying ratios of existing local freight and logistics facilities, the approximate size of potential warehouse buildings were calculated.
The final element of Step 1 was to calculate the estimated daily truck trips generated based upon the potential warehouse building areas. Using GIS, each parcel’s daily truck trips we calculate, a buffer analysis was completed, and interchanges close to one another were consolidated. Then a series of “heat maps” were generated using the point data that included representative daily truck trip information.
Step 2: Identify Deficiencies
Step 2 included completion of capacity analyses for the I-75 interstate mainline and operational analyses for the study area interchanges. Models were utilized for assessment of the mainline existing and 2040 future conditions, and Highway Capacity Manual software and methodology were utilized for interchange operational analyses. The results indicated that segments and interchanges in Henry and Bibb counties may experience poor levels of service by the 2040 horizon year.
Step 3: Assess Truck Freight Routing
Step 3 of the process involved assessing key existing and potential truck routes between freight hotspots, major roadways and I-75. Major truck routes were identified by assessing existing truck routes, as well as feasible alternatives. The routes were superimposed onto freight hotspot heat maps and interchange operational analyses to determine potential deficiencies for key intersections.
Step 4: Develop Recommendations
The final and fourth step of the process is the most critical: the synthesis of the analytical results to determine if improvements are needed. Based on the synthesis of information in this area, a suite of recommendations were developed, including guidelines for the I-75 mainline typical section, major and minor modifications to select interchanges, and the need for potential new interchanges. The results of the ICFP were directly incorporated into these prioritized recommendations.
Conclusions
For the I-75 South Study, the ICFP process has been extremely successful. Using the process has helped effectively prioritize spending, and the resulting recommendations are focused at the interchanges anticipated to experience more intensive freight-related development.
Additionally, the ICFP process provides valuable insight for state and local decision-makers on how local land use decisions directly impact transportation, as well as potential land use conflicts that may be caused by truck-intensive areas. The ICFP methodology provides local officials and stakeholders with a comprehensive and coordinated corridor view of issues and impacts.
Another benefit of the ICFP process is the ability to better align truck, rail and intermodal facilities strategically over larger, regional areas. Because existing and potential future freight hot spot areas are closely clustered, there is the potential for future development of integrated logistics centers (ILCs)/freight villages.
The systematic and coordinated ICFP process provides the opportunity for assessment of public-private coordination in development of potential ILCs and quasi-public funding opportunities for transportation improvement projects.
Finally, the ICFP process provides the opportunity for proactive, strategic policy planning. For the I-75 study, a set of potential tools for local governments have been developed, including a framework informing local zoning overlay districts incorporating truck-friendly roadway standards (including access management) and site development design criteria.
The combination of freight growth and land use growth forecast for the southeastern U.S. and Florida will continue to stress critical infrastructure of national importance, including I-75 South. The ICFP process provides a tool that ensures transportation planning is fully coordinated with land use, economic development and environmental planning.
With appropriate adjustments, a version of the ICFP can be adapted and implemented anywhere to improve conditions for travelers in any state.
