Time To Steer (TTS)

Description

Please refer to the TTM.

Properties

Run-time capability

Yes

Target values

0.47 s [Junietz2018a] (threshold for critical), 1 s [Huber2020] (ADF testing)

Subject type

Optimal for road vehicles (automated and human), sub-optimal for VRUs

Scenario type

Overlapping predicted trajectories for a significant time span in the scenario

Inputs

Static/dynamic objects and their state (pose, shape, etc.) at time t, MM for maneuver ‘steer’

Output scale

\(\{-\infty\} \cup [0,\infty]\), time (s), ratio scale

Reliability

High, under the assumption that collisions can be reliably predicted

Validity

High for two-actor scenes, medium for more actors when TTS is evaluated under a fixed perspective, but can be increased by aggregating over all actors as at least for one of them, the TTS will be valid

Sensitivity

High for non-humans, as steering is often optimal for threat mitigation than braking [Adams1994]; medium for humans as steering maneuvers are seldomly preferred [Adams1994]

Specificity

High under the assumption that the DMM has a low ratio of spurious collision among all predicted collision

Prediction model

Time window

unbound, but usefulness depends on DMM

Time mode

linear time