Passed in 2013, the Strategic Transportation Investments law allows the N.C. Department of Transportation to use its funding more efficiently and effectively to enhance the state's infrastructure, while supporting economic growth, job creation and a higher quality of life. This process encourages thinking from a statewide and regional perspective while also providing flexibility to address local needs.

STI also establishes the Strategic Mobility Formula, which allocates available revenues based on data-driven scoring and local input. It is used to develop NCDOT's State Transportation Improvement Program, which identifies the transportation projects that will receive funding during a specified 10-year period.

Federal law requires the State Transportation Improvement Program to be updated at least every four years. NCDOT, however, updates it every two years.

Work is currently underway to update the STIP for 2020-2029.

Strategic Mobility Formula

The Strategic Mobility Formula allows NCDOT to more efficiently invest its transportation dollars by using a data-driven scoring process along with local input.

For example, the 2016-2025 State Transportation Improvement Plan includes an additional 478 highway projects and is expected to support about 300,000 jobs. That's 300 more projects (a 273 percent increase) and 126,000 more jobs (a 172 percent increase) than what the old funding formula, which distributed money equally across the state, would have allowed.

This data-driven approach yielded one of the state's most comprehensive STIPs ever, with 1,073 projects in all 100 counties, and across all modes of transportation for 2016-2025.

Strategic Mobility Formula: How It Works

The Strategic Mobility Formula funds projects in three categories:

  • Division Needs
  • Regional Impact
  • Statewide Mobility

Division Needs

Projects in this category will receive 30 percent of the available revenue, shared equally over NCDOT's 14 transportation divisions, which are groupings of local counties. Project scores are based 50 percent on data and 50 percent on rankings by local planning organizations and the NCDOT transportation divisions.

Highway projects in this category are analyzed according to five criteria:

  • Congestion (15 percent)
  • Benefit/cost (15 percent)
  • Safety (10 percent)
  • Freight and military (5 percent)
  • Accessibility/Connectivity (5 percent)

Regional Impact

Projects in this category receive 30 percent of available revenue. Projects on this level compete within regions made up of two NCDOT transportation divisions, , with funding divided among the regions based on population. Data makes up 70 percent of the project scores in this category. Local rankings account for the remaining 30 percent.

Regional Impact projects are analyzed according to five criteria:

  • Congestion (20 percent)
  • Benefit/cost (20 percent)
  • Safety (10 percent)
  • Accessibility/connectivity (10 percent)
  • Freight and military (10 percent)

Statewide Mobility

Projects in this category receive 40 percent of available revenue. The project selection process is based 100 percent on data.

Statewide Mobility projects are analyzed according to six criteria:

  • Congestion (30 percent)
  • Benefit/cost (25 percent)
  • Economic competitiveness (10 percent)
  • Safety (15 percent)
  • Multimodal and military (5 percent)
  • Freight and military (15 percent)

STI scoring, weights and criteria were developed in 2013 and updated in 2014 and 2015 by a broad-based group of transportation professionals and stakeholders. They were adopted by the North Carolina Board of Transportation and reported to the North Carolina General Assembly.

NOTE: Statewide Mobility projects are also analyzed separately in the Regional Impact and Division Needs categories and can be funded under those categories if they are not funded in the Statewide Mobility category. Regional Impact projects can also cascade down to the Division Needs category.

A project's benefit/cost can improve when it is funded during the project submission phase through local entity contributions or tolling approved by the local planning organization. In addition, any area contributing to the project – and thereby reducing the cost to NCDOT –can receive back up to 50 percent of the funding for a subsequent project scored through STI.

Alternate Criteria

To provide more flexibility, STI allows regions and divisions to develop alternate criteria tailored to their individual needs. To do so, the metropolitan and rural planning organizations and the NCDOT divisions within the region must unanimously agree on the criteria.

Developing & Updating the STIP

It takes NCDOT about two years to develop the STIP. The process can be broken down into three main phases: Prioritization, Programming and Scheduling, and Review and Approval.


NCDOT uses a transparent, data-driven method for prioritizing transportation investment decisions. Through the process, called Prioritization, potential transportation improvement projects are submitted to NCDOT to be scored and ranked at the statewide, regional and division levels, based on approved criteria such as safety, congestion, benefit-cost and local priorities.

These scores and other factors are used to determine whether a project receives funding.

Programming and Scheduling

Once all project scores and rankings are established, NCDOT uses this information as a primary factor in determining project schedules. Other considerations and requirements – such as the completion of environmental and engineering plans, spending caps, and federal and state funding restrictions – must also be applied to fully develop and complete the picture of when individual projects are scheduled.

Draft STIP Review and Approval

Once individual projects are scheduled, that schedule becomes the Draft State Transportation Improvement Program, which is released to the public for review and comment before final approval by the Board of Transportation. This typically occurs by December of every even-numbered year.