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15 The framework will help state and local agencies follow a systematic methodology to assess the impact of specific automated driving system (ADS) applications on transportation safety.
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16 Framework for Assessing Potential Safety Impacts of Automated Driving Systems defined, it is important to understand the technology and infrastructure dependencies. This helps to understand the risks and opportunities involved.
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Overview of the Framework Elements 17 Step 2 -- Understand the ADS Feature Description of ADS Feature The best sources for understanding the functionality of the ADS feature are the original equip ment manufacturer's user manuals and online technology reviews. These sources not only pro vide a highlevel description of the feature's functions but can help provide context in terms of technology and infrastructure dependencies.
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18 Framework for Assessing Potential Safety Impacts of Automated Driving Systems understanding of the rapid advancement of technologies focused on Level 3 and 4 vehicle technologies that directly affect stakeholders. The predictions were extrapolated for both the high and lowdisruption scenarios.
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Overview of the Framework Elements 19 On the other hand, the future of the deployment rate of the ADS is speculative and could follow diverse scenarios since it hinges on several interrelated factors, such as reliability of tech nology, regulatory challenges, and consumer acceptance and willingness to pay. For instance, technology innovations in this area would continuously supersede firstgeneration technologies by more advanced systems.
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20 Framework for Assessing Potential Safety Impacts of Automated Driving Systems early deployments of ADS have revealed contextdependent challenges with perception systems in various environmental conditions (e.g., weather) and infrastructure conditions (e.g., lane marking reflectivity)
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Overview of the Framework Elements 21 to improve safety. If safety is not a primary or secondary goal, then the safety goal should be written as "the goal is to not degrade existing safety performance." Operational design domains: The goal(s)
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22 Framework for Assessing Potential Safety Impacts of Automated Driving Systems facility type(s) and area(s)
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Overview of the Framework Elements 23 Example 2: sequence of events for vehicle-vehicle crash at intersection: Mapping the crash sequence is also useful for identifying potential increases in collisions with the introduction of ADS. The following is a continuation of the pedestrian crash example above but now considers an ADS scenario where vehicle 1 is equipped with forward collision warning but vehicle 2 is not.
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24 Framework for Assessing Potential Safety Impacts of Automated Driving Systems aggressive driving behaviors, which are a precursor to the crashes (e.g., will conditional traffic jam assist reduce driver frustration and erratic lanechange maneuvers?
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Overview of the Framework Elements 25 Dimension Example Processes and Procedures Example Questions Planning • Strategic Highway Safety Plan (SHSP)
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26 Framework for Assessing Potential Safety Impacts of Automated Driving Systems There are several sources of crash costs by severity level, including the Highway Safety Manual (HSM) and FHWA's Crash Costs for Highway Safety Analysis (Harmon et al., 2018)
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Overview of the Framework Elements 27 different crash types are known (or assumed) , then these datasets can be used to quantify the number of crashes by type and severity that could be impacted by the various ADS technologies under different deployment scenarios.
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28 Framework for Assessing Potential Safety Impacts of Automated Driving Systems disaggregate ADS safety performance estimates with and without those conditions. Datasets under this category include Highway Performance Monitoring System, HSIS roadway data, and state and local roadway inventory files.
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Overview of the Framework Elements 29 This avoids doublecounting crashes in the analysis. Potential safety benefits are not simply addi tive between the ADS features.
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30 Framework for Assessing Potential Safety Impacts of Automated Driving Systems Skill degradation: When drivers use ADS features frequently and do not use their own driving skills often, they might lose or diminish their driving skills (Parasuraman et al., 2000)
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Overview of the Framework Elements 31 Figure 8. Example of road network in IHSDM (Source: IHSDM Project Output)
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32 Framework for Assessing Potential Safety Impacts of Automated Driving Systems crashes, for a particular ADS feature, as a function of crash severity type, ADS market penetra tion, corresponding crash cost, and CMF for ADS. ∑=Monetary value of crashes after p p pADS deployment N MP Cost CMFCrash ADS sev ADSsev Eq.1 where: NCrash = Total crash by severity type (crash count by type)
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Overview of the Framework Elements 33 Historical crash data broken down by severity type following the KABCO classification can be obtained from local and state law enforcement or transportation agencies. The data should be classified by annual occurrence to find the annual vehicle crash cost and savings.
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34 Framework for Assessing Potential Safety Impacts of Automated Driving Systems Body Type Year 2018 Passenger cars 20,333 Light trucks 19,775 Large trucks 4,862 Motorcycles 5,115 Buses 234 Other/unknown 1,553 1https://www-fars.nhtsa.dot.gov/Vehicles/VehiclesAllVehicles.aspx. Table 10.
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Overview of the Framework Elements 35 defined regional scale. The approach was applied to the state of Minnesota; Table 12 lists the Minnesota fatalities by vehicle type for the year 2018.
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36 Framework for Assessing Potential Safety Impacts of Automated Driving Systems Bus Fatality Costs Market Penetration 0% 20% 40% 60% 80% 100% Bus fatality cost without ADS $105 $119 $124 $129 $142 $220 Bus fatality cost with ADS $105 $103 $85 $74 $62 $66 Bus fatality savings with ADS $0 $16 $38 $55 $81 $154 Table 13. Minnesota monetary costs and savings (millions)
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Overview of the Framework Elements 37 heading to a passenger or even cruising waiting for a passenger. An estimate for the nonzero occupancy induced trips could be calculated using the following equations: = × × × Eq.
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38 Framework for Assessing Potential Safety Impacts of Automated Driving Systems Economic Value of Trips Estimates of the economic value of each nonzerooccupancy trip can be based on guidance from the Federal Emergency Management Agency, which assumes a delay time of halfday (12 hours) per trip to reflect the loss in productivity and spending for each trip that is not made (i.e., when the trip does not happen, the economy is less productive and there is less spending overall)
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Overview of the Framework Elements 39 Virginia 9,674.7 9,444.5 9,168.0 8,909.1 Location 2016 2017 2018 2019 United States 371,725.6 375,118.3 374,602.1 367,306.0 Minnesota 6,592.5 6,382.7 6,218.3 6,305.1 Table 14. Thousand gallons per day average petroleum sale (motor gasoline)
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40 Framework for Assessing Potential Safety Impacts of Automated Driving Systems The framework can serve the needs of both technical and nontechnical audiences. These audi ences may include OEMs, technical developers, IOOs, policymakers, community advocates, and regulatory staff.
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Overview of the Framework Elements 41 • Economic measures such as the benefitcost ratio or cost effectiveness to support investment decisions. While the technical audiences may have some degree of familiarity with ADS technology and/or quantitative safety measures (e.g., expected changes in crash frequency and severity)
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42 Framework for Assessing Potential Safety Impacts of Automated Driving Systems from transportation agencies? Or from their constituents?
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