ISO/TR 21974-1:2018 自然主義的な運転研究—用語, 語彙—パート1：セーフティクリティカルイベント | ページ 6

3.1

combined avoidance capacity

total response capacity of all responding conflict partners (3.3)

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; 3.3) led to one of three results: 1) a crash (3.4) or road departure (3.12) , 2) a situation where an evasive manoeuvre(s) (3.5) was required to avoid a crash or road departure, or 3) an unsafe proximity between the conflict partners

Note 1 to 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 (3.3)

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 (3.4)

3.3

conflict partner

any entity that is part of a conflict (3.2)

Note 1 to entry: This may include other vehicles (3.18) , pedestrians (3.10) , pedal cyclists (3.9) , other non-motorists (3.8) , 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 (3.3) 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 (3.3) to change its trajectory or speed in an attempt to avoid or reduce the severity of a potential crash (3.4) , avoid or reduce 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.

3.8

non-motorist

non-motorized conveyance

person is being transported by a non-motorized conveyance, other than a pedaled cycle (3.9) /a human-powered device by which a non-motorist may move or may move another non-motorist

3.9

pedal cyclist

person on any type of manually propelled pedaled cycle, as either the driver or the passenger, including bicycles, tricycles, and unicycles

Note 1 to entry: This category includes pedal cyclists holding on to a motorized vehicle.

Note 2 to entry: This category also includes power-assisted pedaled cycles that have limitations on speed (i.e., pedelecs). Pedaled cycles that are capable of propelling themselves and do not require pedaling for propulsion are not included in this category (see “Motorcycle or moped”).

3.10

pedestrian

any person who is on or near a roadway (3.11) or a sidewalk, path, or other space that is contiguous with a roadway, or on areas beside the roadway into which a vehicle can travel, and who is not in or on either a motorized or a non-motorized conveyance

Note 1 to entry: This includes persons who are in contact with the ground, roadway, etc., but who are holding on to a vehicle.

3.11

roadway

portion of a trafficway (3.15) that is designed and ordinarily used for vehicular travel, including all designated or implied travel lanes (through lanes, turn lanes, acceleration and deceleration lanes), but not shoulders, painted (whether usable or not), medians of any type, roadsides, gore areas, etc., that are of a similar road surface to the parking lanes, parking areas, or driveways

3.12

road departure

conflict (3.2) in which the subject vehicle (3.14) is on a path toward and crosses, or is at risk of crossing, the road edge

Note 1 to entry: The road edge is the outside edge of the shoulder (if present) or a physical raised curb or median on the left or right side of the trafficway, including low barriers such as curbs and curb-style medians that are within the ground clearance of the vehicle.

3.13

safety-critical event

SCE

conflict (3.2) or series of related conflicts that involves the subject vehicle (3.14) either alone or in combination with another vehicle (3.18) , pedal cyclist (3.9) , pedestrian (3.10) , object, or road edge

Note 1 to entry: This document describes the range of conflict types that may comprise an SCE, and an SCE may be composed of a single conflict type or multiple simultaneous or sequential conflict types. Conflicts should be non-intentional and non-premeditated (unplanned) by at least one conflict partner (3.3) .

3.14

subject vehicle

vehicle (3.18) that has been instrumented and collects data

Note 1 to entry: Available videos will capture images from the subject vehicle’s perspective.

Note 2 to entry: Kinematic data are typically available only from the subject vehicle or (in the case of radar data) the subject vehicle’s perspective.

3.15

trafficway

any right-of-way designated for moving persons or property from one place to another, including the surface on which vehicles normally travel (i.e., the roadway; 3.11), plus the shoulders, painted medians, and painted gore areas at grade with the roadway

Note 1 to entry: The trafficway also includes parking lanes and parking areas (e.g., parking lots, driveways).

Note 2 to entry: The trafficway is bound by the outer edges of the shoulder or by raised roadside barriers (e.g., curb, guardrail, pylon) and thus does not include raised medians, grassy medians, sidewalks, etc.

3.16

trigger

data analysis method that includes the application of algorithms (e.g., acceleration thresholds) for searching time series driving data for key situational characteristics or thresholds in order to identify potential events of interest (e.g., kinematic threshold for potential SCEs; 3.13)

3.17

urgent response

urgency of response

situation in which the required evasive manoeuvre (3.5) approaches the combined avoidance capacity (3.1) of the responding conflict partners (3.3) required to prevent a crash

Note 1 to entry: Both the time available for response and the required response magnitude (e.g., level of deceleration) should be considered.

Note 2 to entry: While it may be possible to quantify the required urgency of the evasive manoeuvre (see Annex A for more discussion), the methods for doing so are not within the scope of this document. Quantification of the urgency is not required in order to use the concept as described in this document.

Note 3 to entry: The urgency of the response is independent of any evasive manoeuvres that are actually performed.

3.18

vehicle

any motorized means of transportation, excluding pedelecs, which are included in the pedal cyclist definition (3.9)