Driver adaptation to road narrowing: reducing speed or increasing neuromuscular stiffness?
E.W.M. Hogerwerf (TU Delft - Mechanical Engineering)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Drivers continuously adapt to the different needs and constraints in the driving scene. Literature has provided evidence for two adaptation strategies in response to an increased risk (decreasing the road width or increasing the driving speed) while lane keeping: decreasing driving speed and increasing endpoint arm stiffness. However, so far these studies did not investigate the interaction between the two adaptation strategies. The aim of this study is to find the interaction between drivers’ speed and neuromuscular adaptation for different risk durations. We hypothesize that the speed reduction is larger when the narrow road is longer which allows for a lesser increase in arm stiffness. Additionally, when the narrow road is shorter the increase in neuromuscular stiffness is larger and allows for a higher speed.
Twenty-six participants drove in a driving simulator experiment in a 1.8m wide car on a 35 km long road. Different levels of risk durations were imposed to the drivers on straight road sections by a road narrowing (from 3.6m to 2.2m) with a varying length (10m, 100m, 250m, and 500m). During the experiment speed reduction was measured and neuromuscular adaptation was quantified by measuring the grip force. Additionally participants subjectively rated their experienced effort from 1-10.
The results show that participants adapted to the road narrowing both by speed reduction as well as increased grip force, without significant impact of the length of the road narrowing. Only on the 10m narrow the speed reduction and increase in grip force was smaller compared to the other three cases. Interestingly, although drivers increased their subjective effort, no differences in speed and grip force adaptation were found between the three longest narrow roads. These results suggest that for narrow road lengths up to 500m drivers adapt their driving style to road width rather than road length. Future studies should identify if the identified speed and grip force adaptations also hold for longer and different durations of risk.