2030 Comprehensive Plan Update, April 2024

Transportation

Thresholds for Transportation Impact Analysis NCDOT has adopted guidelines for when and how a Transportation Impact Analysis (TIA) should be performed. Many local jurisdictions, including Wake County, have also adopted TIA thresholds, typically lower than those chosen by NCDOT. NCDOT recommends a TIA when one of the following conditions is met: • Access is from a four-lane street or greater. • Daily trips exceed 3,000 vehicles per day (VPD). • Within 1,000 feet of an interchange. • Affects a location with a high crash history. • Involves existing or proposed median crossover. • Involves an active roadway construction project. • Involves an active TIP project. Some example thresholds from local jurisdictions include: • City of Durham: peak hour trips ≥ 150 Vehicles per hour (VPH). • Wake County: peak hour trips ≥ 100 VPH or daily trips ≥ 1,000 VPD. • Town of Cary: peak hour trips ≥ 20 VPH and any development where expected trips exceed traffic generated by R-20 development (2.2 units per acre). • City of Charlotte: daily trips ≥ 2,500 VPD; or affects a location with a high crash history; or takes place at a high congestion location (vehicles/capacity > 1); or creates a fourth leg

at an existing signalized intersection; or exacerbates an already difficult situation (railroad crossing, school access, etc.).

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