Communications Infrastructure and Two Safety Systems for Crash Avoidance, Wrong-Way Driver Detection and Curve Departure Warning, were Installed at 44 Pilot Locations and Off-Ramps on the I-85/I-40 Route in North Carolina.
Benefit‐Cost Analysis for the I‐85/I‐40/NC‐540 Foundations for Automated and Safer Transportation Project
The North Carolina Department of Transportation (NCDOT) I-85/I-40/NC-540 Foundations for Automated and Safer Transportation Project is set to add a fiber-optic trunk line connection between the state's two largest Transportation Management Centers (TMC) along I-85/I-40, once it is completed. The primary objective of this investment is to create opportunities for NCDOT and the private sector to jointly utilize the communications infrastructure. The project study estimated the long-term benefits of the project, which include the installation of two safety systems, namely wrong-way driver detection and curve departure warning, at 15 pilot locations along I-85/I-40 to deter wrong-way driver and curve departure crashes. Additionally, countermeasures for wrong-way drivers are to be installed at 29 off-ramps along the North Carolina Turnpike Authority's (NCTA's) Triangle Expressway. The project is also expected to add technology to interstate alternate routes and aid in integrated corridor management (ICM). The added wireless communication infrastructure will support future connected and automated vehicle technology. The project construction is scheduled to be completed by mid-2024.
The benefits of the project were calculated for an analysis period of 2024-2043 estimated according to guidance given by U.S. Department of Transportation (USDOT) for a benefit-cost analysis. The benefits were calculated in 2020 dollars for each project element. The total annual benefits of the project were calculated in terms of reduction in crashes, economic competitiveness in terms of the benefits of the completed fiber optic line and reliability savings from ICM, and cost reductions in leased communication lines. The benefits for each of these project elements were reported as follows:
- Reduction in fatalities and crashes: The project’s quantitative safety benefits derive from the expectation of reduced crashes at the wrong‐way driver countermeasure sites. The total benefit of crash reduction was calculated by using the unit annual value of crashes adopted from the 2020 Benefit‐Cost Analysis Guidance document by the USDOT.
- Fiber benefit: This benefit was quantified using a willingness to pay (WTP) methodology. Although a typical home internet speed was assumed to be 25 megabits per second (MBPS), a conservative value of four MBPS was used ($10.37 per household) based on the review of the relevant literature.
- Travel time reliability savings from ICM: ICM would allow the corridor to be centrally managed and, therefore, would provide benefits to users from increased efficiencies. This benefit was estimated by the Federal Highway Administration (FHWA) for pilot studies in San Diego, Dallas, and Minneapolis (ranged from 3.3 to 10.6 percent). For a conservative measure, four percent was used in the analysis.
- NCDOT/NCTA Fiber Savings: Fiber connection savings would be due to the reduced dependence on the leased communication lines and were calculated for the NCDOT Regional TMC as $1,000 per month and for the NCTA’s tolled roads as $2,250 per month.
The following benefits have been discounted at a rate of seven percent over a 20-year period (2024-2043):
- The reduction in fatalities and crashes on the project is estimated to yield benefits of $11.1 million.
- The fiber benefits for the project total $6.9 million.
- Travel time reliability savings from ICM amount to $36.2 million.
- The NCDOT and North Carolina Turnpike Authority (NCTA) fiber savings are calculated to be $600,000.
- The project's total Benefit/Cost Ratio is 2.95, with a net present value of $32.7 million.