In-vehicle rollover advisory control warning messages are expected to prevent 20 percent of rollover crashes caused by excessive speed in curves, based on driving data collected during a Freightliner FOT.

September 2003
United States

Summary Information

In 1999, the U.S. DOT entered into cooperative agreements with four partnerships to conduct Generation 0 Field Operational Tests (FOTs) of advanced intelligent vehicle safety systems (IVSS). Freightliner—in partnership with Praxair, the fleet operator; the University of Michigan Transportation Research Institute (UMTRI), the technology integrator; and Meritor-Wabco, the component supplier—tested two related but distinct functions of a new Roll Advisor and Control (RA&C) system. The RA&C system is designed to assist commercial vehicle drivers, especially drivers of tanker trucks, in avoiding rollover crashes. The benefits of RA&C for helping to avoid single vehicle roadway departure (SVRD) crashes were also evaluated. The first component is the Roll Stability Advisor (RSA), which is intended as an educational tool for drivers. The RSA will not prevent any particular crash through direct intervention. Instead, it merely advises a driver, after a maneuver is finished, that the lateral forces on the vehicle were higher than might have been desirable. The RSA’s advisory notices are provided to the driver as briefly worded messages appearing on the instrument panel display. The second component is the Roll Stability Control (RSC). This system takes partial, momentary control of the vehicle if it deems that a serious rollover threat is developing. The system’s authority in the FOT was limited to reducing the throttle or applying engine braking. Only a minimal amount of deceleration is applied in this manner, but the hope is that a bad situation can be prevented from becoming worse.


Data sources included historical crash data, engineering data collected in the course of the FOT, special track tests, and driver interviews. Time domain vehicle dynamic simulations and statistical models were used to estimate safety benefits (i.e., crash reductions).
  • Based on driving data collected during the Freightliner FOT, in-vehicle rollover advisory control warning messages are expected to prevent 20 percent of rollover crashes caused by excessive speed in curves.
  • For the national fleet of approximately 110,000 tanker trucks, the warning messages have the potential to prevent 34 crashes, 21 injuries, and 2 to 3 fatalities per year.
rollover advisory control, warning messages

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Evaluation of the Freightliner Intelligent Vehicle Initiative Field Operational Test: Final Report

Author: Battelle

Published By: U.S. DOT Federal Highway Administration

Prepared by Battelle for the U.S. DOT FHWA

Source Date: September 2003

EDL Number: 13871

Other Reference Number: FHWA-OP-03-179


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Benefit ID: 2008-00575