A farewell to brake reaction times? Kinematics-dependent brake response in naturalistic rear-end emergencies

Abstract

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A quantitative driver model of pre-crash brake onset and control

“…In this section, this will be illustrated by reproducing two figures from Markkula et al (2016), comparing results from the simulated Euro NCAP scenarios to the original figures, which are based on analysis of empirical data reported from the SHRP 2 naturalistic study. The data are divided into crash events, defined as the vehicles touching each other, and nearcrash events, defined as events where the driver model brakes with a maximum deceleration exceeding 0.5 g. The latter is similar to the SHRP 2 near-crash definition, although not an exact match since the SHRP 2 data were also manually annotated (see Victor et al, 2015).…”

“…In such models, the driver's reaction is typically initiated by what is assumed to be a sudden threat appearance, for example a brake light onset of the vehicle in front. However, recent analyses of real crashes and nearcrashes in the second Strategic Highway Research Program (SHRP 2) dataset have shown a strong dependency on kinematics for both brake initiation and brake ramp-up, inconsistent with the existing situation-independent models (Markkula, Engström, Lodin, Bärgman & Victor, 2016).…”

“…Therefore, the simulations were set up in a manner so that the glances first started at the anchor point, and for each simulation run the glance starting point was incrementally moved 0.2 s backwards in time until the glance no longer overlapped the anchor point (i.e., assuming equal probability of glance initiation at these times). Since the aim is to simulate the last glance off-road, scenarios with glances ending before the anchor point are here treated as equivalent to scenarios where the driver looks ahead for the entire scenario (called "eyes-on-threat" scenarios by Markkula et al, 2016) and are out of scope for the current simulations. …”

“…Markkula et al (2016) suggested that their findings from SHRP 2 naturalistic driving data could be explained if the driver's brake initiation is not solely related to the crossing of a looming threshold, but to noisy evidence accumulation of looming and other perceptual input over time, a type of mechanism for which there is much support from laboratory tasks in psychology and neuroscience (Gold & Shadlen, 2007). Combining this model mechanism with other well proven neuroscientific concepts, especially motor primitives (Giszter, 2015) and prediction of sensory outcomes of motor actions (Crape & Sommer, 2008), Markkula and colleagues (Markkula, 2014;Markkula, Boer Romano & Merat, 2017) have developed a computational framework for driver control behaviour.…”

Simulating the effect of cognitive load on braking responses in lead vehicle braking scenarios

“…Moreover, our recent analysis of real rear-end crashes and near-crashes indicated that the timing of drivers' braking responses could be largely explained in terms of visual looming cues (reflecting situation kinematics) while the timing relation between drivers' reactions and lead vehicle brake light onsets was more variable [27].…”