ISO TR 21974-1:2018 pdf free.Naturalistic driving studies一Vocabulary一Part 1:Safety critical events.
3 Terms and definitions
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3.1 combined avoidance capacity
total response capacity of all responding conflict partners (i)
Note 1 to entry: The capacity of a responding conflict partner takes into account both the abilities and limitations of the vehicle or road user as well as any environmental or infrastructural constraints, if present.
Note 2 to entry: Conflict partners that do not exhibit an observable response are not included in this construct.
3.2 conflict
situation where the trajectory(ies) of one or more road users or objects (conflict partner; ,..3) led to one of three results: 1) a crash (14) or road departure (3.12), 2) a situation where an evasive manoeuvre(s) (IS) was required to avoid a crash or road departure, or 3) an unsafe proximity between the conflict partners
Note ito entry: The key concept underlying the present framework is that of conflict.
Note 2 to entry: Three general classes of traffic conflict are of interest in naturalistic driving analyses: trajectory conflict (3.2.1), single-vehicle conflict (3.2.2), and proximity conflict (3.2.3).
3.2.1 trajectory conflict
crash course between at least two conflict partners (33)
3.2.2 single-vehicle conflict
conflict (3.2) involving loss of vehicle control (e.g., horizontal and/or lateral skidding or rotation) or
proximity to the road edges (e.g, road departure; 3.12) rather than proximity to another entity
3.2.3 proximity conflict
conflict (3.2) involving two or more entities that are not on a crash course but nevertheless come in close temporal and/or spatial proximity to a crash (3A)
3.3 conflict partner any entity that is part of a conflict (32)
Note 1 to entry: This may include other vehicles (3.18), pedestrians (3.10), pedal cyclists (3.9), other non-motorists (3.), other road users, animals, and objects (including roadside barriers that exceed the ground clearance of the affected vehicle).
Note 2 to entry: If a conflict partner (3.3) is present, then the conflict is either a trajectory conflict (3.2.1) or a proximity conflict (3.2.3).
Note 3 to entry: Low roadside barriers (e.g., curbs) within the ground clearance of the vehicle are not considered conflict partners.
3.4 crash
situation in which the subject vehicle (i.e., instrumented vehicle; 3.14) has any contact with at least one other conflict partner (13) either on or off the trafficway (3.15), either moving or stationary (fixed or non-fixed), that is observable or in which kinetic energy is measurably transferred or dissipated
Note 1 to entry: This excludes roadway (3.11) features meant to be driven over such as speed bumps and low roadside barriers (curbs, medians, etc.) within the ground clearance limitations of the vehicle.
Note 2 to entry: A crash may also be a single-vehicle conflict (3.2.2) that includes at least one of the following conditions: vehicle rollover, airbag deployment, injury, more than 90° degrees of horizontal vehicle rotation, or all four tires leaving the trafficway.
3.5 evasive manoeuvre
any action performed by any conflict partner (3) to change its trajectory or speed in an attempt to avoid or reduce the severity of a potential crash (3A), avoid or i-educe the severity of a road departure (3.12), or regain vehicular control after a loss of control
Note 1 to entry: Examples include steering, braking, accelerating, running, stopping, or a combination of these. Note 2 to entry: At least one of the manoeuvres exceeds normal vehicle control inputs.
3.6 metadata
information that provides a description about the structural content of its referenced dataset or the methods with which the data were collected
Note 1 to entry: Examples of metadata include location (e.g., country, region) of data collection, sampling methods, units of measure, etc.
3.7 naturalistic driving study NDS
any driving study where research subjects are recruited to drive on public roads (not in a simulator or on a test track), where there is no in-vehicle experimenter or confederate vehicles, and where driving conditions are not experimentally controlled or manipulated
Note 1 to entry: Subjects are not instructed to drive differently than they normally would, and the data collection instrumentation is unobtrusive.
Note 2 to entry: Typically, these studies last a minimum of several weeks for each subject and can go much longer.ISO TR 21974-1 pdf download.