We are pleased to introduce one more reason to choose Thomas Built Buses and Carolina Thomas. Electronic Stability Control (ESC) is now standard and factory installed on all new Saf-T-Liner C2 diesel and CNG school and activity buses.
ESC systems have been required by law for all passenger vehicles in the U.S. since 2012, and for air brake-equipped commercial vehicles exceeding 33,000 GVW – heavy trucks and large buses – since August 2017. As a result of several recent school bus crashes, the National Transportation Safety Board (NTSB) and the National Highway Traffic Safety Administration (NHTSA) now recommend that manufacturers install electronic stability controls on all buses. Why is electronic stability control important and what exactly does it do?
What is electronic stability control?
In a nutshell, electronic stability control assists school bus drivers by detecting when a school bus is unstable and corrects the path of the bus before a rollover or loss of control occurs. This may be especially likely on a slippery curve or during an evasive maneuver. Because the technology can sense the stability and dynamics of a bus better than drivers can, it can help eliminate accidents before they happen.
How does it work?
When faced with the risk of a rollover or loss-of-control, drivers usually are not aware that vehicle dynamics are about to become critically unstable until the point of no return already has been reached. Meritor WABCO’s SmartTrac ESC automatically intervenes by comparing the vehicle’s actual movement to performance models, using various vehicle sensors. If the vehicle shows a tendency to leave the driver’s intended path or exceeds a critical acceleration threshold, SmartTrac ESC helps the driver maintain control. The system does this by:
- Applying automatic braking of individual wheels to slow movement and align the vehicle with the driver’s intended path of travel.
- De-fueling the engine, if required, to slow the vehicle.
- Applying the engine brake (if equipped).
What types of crashes does it prevent?
When a driver attempts an extreme maneuver (for example, to avoid a crash or because a curve’s severity has been misjudged), they may be unfamiliar with handing the vehicle as it nears the limits of road traction. ESC can help the driver maintain or regain control in such situations as:
- An evasive maneuver to avoid a collision or an emergency lane change
- Too high rate of speed in tight turns or curves
- Over-correction when the vehicle leaves the road
- Oversteering or understeering in an emergency situation
Electronic stability control in action
For a demonstration of electronic stability control (ESC) in action under extreme heavy-duty road test conditions, watch this video. Icy road conditions and heavily-loaded trailers are used in the video to test for the “worst case” scenario, but ESC works as well in normal and less severe driving conditions. (Be sure to look for the Thomas Saf-T-Liner C2 activity bus, which was tested at the same time, in the background.)
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Eastern Regional Sales Manager
Western Regional Sales Manager