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I-77 and STI Scoring

In response to a number of questions about the I-77 managed lanes project, NCDOT staff ran hypothetical scoring of the project through the same data-driven criteria as all other projects scored under the Strategic Transportation Investment law. The law uses the Strategic Mobility Formula to allocate available transportation infrastructure funds to projects using data-driven scoring (and local input on the Regional and Division Level).Under the STI law all projects that were projected for construction after July 1, 2015 are subject to scoring under the new funding formula. All highway projects are scored using the same five criteria:

Travel Time, Benefit/Cost: 30%

Congestion: 30%

Economic Competitiveness: 10%

Safety: 10%

Multimodal & Freight + Military: 20%

The STI law also establishes a corridor cap, stating no more than 10% (or about $200 million) may be assigned to any one project or group of projects within the same corridor during a five year period.

Because the I-77 North Managed Lanes (North of I-277) project is scheduled to begin construction before July 1, 2015 it is not subject to the new law and was not scored under STI. The I-77 North Managed Lanes is moving forward as a transition project instead.

Thisspreadsheet shows the actual STI scores for the I-77 South (South of I-277) projects and the hypothetical scores created for the I-77 North projects (if constructed as general purpose lanes instead of managed lanes). ** It is important to note all I-77 projects are part of the same corridor, and are subject to the same $200 million corridor cap.

Using the same criteria to produce a hypothetical score there is no section of I-77 North that would score high enough, or fall within corridor cap limits, to be funded for construction for at least the next ten years under the law. As indicated in the attached table, the I-77 South projects would out score, and use all of the corridor funds available for at least the next ten years because quantitative data shows greatest congestion in the south.

The I-77 Managed Lanes Project, through a public private partnership will instead be completed within four years. Upon completion drivers will have the choice to pay to use managed lanes or remain in general purpose lanes for free.

Under STI, right of way purchase for the I-77 South projects begin in 2024, with actual construction still further out.

Additional Information on Managed Lanes vs. General Purpose Lanes

NCDOT last widened I-77 using general purpose lanes in 1997. Because of growth traffic volumes exceeded what the road could handle, and the road was congested again by 2004.

Managed lanes will create congestion free lanes for at least 50 years, making it a longer lasting solution in addition to being a faster solution compared to general purpose lanes.

If the project scope for I-77 North was changed from managed lanes to general purpose lanes it would require additional environmental studies and could no longer move forward as a transition project.

Therefore, NCDOT is continuing with its plan to provide congestion relief to the I-77 North corridor using the transition managed lanes project.I-77 Express Lanes


2/15/2018 5:23 PM