Statewide, Minnesota, United States
Benefit:Cost Analysis of In-Vehicle Technologies and Infrastructure Modifications as a Means to Prevent Crashes Along Curves and Shoulders
Summary Information
In this study, new emerging technologies were studied against traditional infrastructure-based safety systems for reducing road departure crashes on both tangent segments and curves in Minnesota. These emerging technologies and traditional infrastructure solutions were evaluated based on their effectiveness in reducing crashes, market penetration, legal implications, cost effectiveness and their contribution to the "To Zero Deaths" initiative (TZD). An optimum solution has been provided. The benefit-cost analysis was conducted based on results of a before and after study, as well as a cross-sectional study, conducted on a sample of road segments and curves in Minnesota.
Findings
In order to curb roadway departures on tangential sections of roadways, two technology-based solutions were evaluated: Vision-based Lane Departure Warning Systems (LDWS) and Differential GPS (DGPS)-based LDWS. Because these technologies are relatively new and are also in-vehicle technologies, some assumptions were required in order to conduct the benefit-cost analysis (BCA). First, efficiency is characterized by either "optimistic" or "pessimistic", based on surveys of both motor vehicle and motor carrier drivers that had tested the technology. The optimistic efficiency rate is the higher estimate (50 percent), while the pessimistic is the lower estimate (23 percent). Because the technology is in the vehicles and not on the road, assumptions also had to be made based on the rate of adoption of the two technologies by consumers. The "mandatory model" was generated based on the adoption of seat belts, while the "non-mandatory model" was generated based on the adoption of anti-lock breaking systems.
Overall, the vision-based LDWS had a higher benefit-cost ratio than the DGPS-based LDWS under the same conditions, regardless of whether the efficiencies were optimistic or pessimistic and whether adoption of the technology was made mandatory or not. The extremely high cost for creating the infrastructure (paid for by the state) for a DGPS-based LDWS as well as high costs for early adopters (consumers), had a large impact on the BCA. Full calculations for the BCA can be found in Appendix K of the source document.
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10 Year Analysis
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20 Year Analysis
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Optimistic Efficiency
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Pessimistic Efficiency
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Optimistic Efficiency
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Pessimistic Efficiency
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Vision-Based LDWS
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Mandatory Model
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6.55
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2.77
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19.16
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8.18
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Non-Mandatory Model
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3.69
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1.56
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12.51
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5.35
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DGPS-Based LDWS
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Mandatory Model
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1.26
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0.63
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6.86
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3.38
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Non-Mandatory Model
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1.04
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0.52
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3.69
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1.82
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Table 10.3 Benefit:Cost Ratios for Tangential Sections
