Headway (HW)

Description

Please refer to the THW.

Properties

Run-time capability

Yes

Target values

50 m [Junietz2018a] (threshold for fines)

Subject type

Road vehicles (automated and human)

Scenario type

Car following scenarios

Inputs

Positions \(p_i\) for \(i \in \{1, 2\}\), information to determine lead vehicles

Output scale

\([0,\infty)\), meter (m), ratio scale

Reliability

Low, as many changes in criticality (e.g. significantly higher speed in a situation) are not reflected by HW

Validity

Medium, a small distance to front does not always imply high criticality, but is also a factor present in many accidents

Sensitivity

High, as indicated by the use of HW in legislation [Junietz2018a], most critical situations do imply small distance to front for at least one involved actors

Specificity

Low, as a large distance to front does not always imply low criticality

Prediction model

Time window

Unbound, but usefulness depends on DMM

Time mode

Linear time