Effect of Shoulder Width and Drop-off on Vehicle Rollover and
Shoulder Crossover Using Vehicle Dynamics Simulations
Morteza Hossein Sabbaghian, Corresponding Author
Researcher, Young Researcher and Elites Club, Science and Research Branch, Islamic Azad
University, Tehran, Iran.
Tel: +98-9127904010; Email: [email protected]
Ali Abdi Kordani
Assistant Professor, Department of Civil Engineering, Imam Khomeini International University.
Tel: +98-9126085308; Email: [email protected]
Behrouz Tavassoli Kallebasti
MSc, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Tel: +98-9115784734; Email: [email protected]
Ali Attari
MSc, Ahar Branch, Islamic Azad University, Ahar, Iran.
Tel: +98-9149564808; Email: [email protected]
Word count: 3488 words text + 12 tables/figures x 250 words (each) = 6488 words
TRR Paper number: 151
Submission Date: 20/03/15
Sabbaghian, Abdi, Tavassoli, Attari
ABSTRACT
Shoulder is practically the last safe opportunity for drivers to recover the vehicle when it is
errant and traveling off the traveled way. This study presents an analysis of highway shoulder
safety through the use of simple point-mass cornering model and dynamic simulations of vehicles.
The commercially available software CarSim® was used to simulate four different encroachment
trajectories. Various factors, including shoulder width, shoulder edge drop-off, and their respective
influence on accident causation, were investigated. The results from the investigations presented
in this study could be as design guidance for highway engineers. The results indicate that overall
safety of a shoulder depends on the occurrence of both shoulder crossover and vehicle rollover
events. Based on this research, as the design engineer develops a new shoulder, they can design an
appropriate geometry to prevent crossover/rollover events. For example, if an existed shoulder
width be enhanced from 1 meter to only 2.6 meter, the rate of rollover incidents could be expected
to be reduced for about two percent. Furthermore, simulation of all different scenarios indicated
that when shoulder edge drop off is present the roll angle graph indicates a much higher roll angle
compared with otherwise.
Keywords: Shoulder safety; Skidding; Rollover; Shoulder width; Drop-off; Multi-body simulation.
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