Addressing Real-Life Safety Issues
‘Real world’ safety issues such as child safety and collisions between two vehicles of differing weights and sizes were addressed during the development of the new Prius.
Impacts between different size and weight vehicles constitute the most common type of accident in Europe, so the Prius was crashed into the much larger Toyota Land Cruiser as part of the testing regime, both vehicles moving at 50 km/h. The results of this testing mean that Prius occupants enjoy the highest possible levels of protection in real-life front, side and rear impacts.
To cope with rear impacts, the body strength was increased and the seat back structure was reinforced. The Prius is also fitted with Toyota’s WIL (Whiplash Injury Lessening) seat design that protects the passengers’ necks from whiplash effects. WIL seats were recognised by the German national motoring organisation ADAC as the best among 10 different whiplash protection systems.
Both the high-voltage electric circuit and the fuel tank enjoy maximum protection in an impact. The hybrid battery is mounted over the rear axle – the safest place in the event of a crash – and the Circuit Break Sensor instantly disconnects the High-Voltage Power Circuit in the event of a frontal impact, operating even before the airbags are fully deployed.
The fuel tank uses a new lightweight plastic multiplex design with maximum impact resistance. Even following a 50km/h rear impact from an SUV, the fuel tank suffers no leakage.
Class Leading Active Safety
Besides being a D-segment top performer in passive safety, the Toyota Prius was also designed to set an example in terms of active safety. To this end, it is fitted as standard with features that are unique in the class: ‘by-wire’ Electronically Controlled Braking (ECB2), Electric Traction Control (E-TRC) and advanced Vehicle Stability Control Plus (VSC+).
The innovative ‘by-wire’ ECB2 braking system uses brake pedal-activated electronic sensors to communicate braking feel to the driver and control the braking hydraulics. It not only generates higher hydraulic pressures than conventional systems, but it is also 17 per cent lighter.
The Prius is the world’s first car to be fitted with Electric Traction Control (E-TRC). The system controls wheel slippage via ECB2 and the high-torque electric motor element of the Hybrid Synergy Drive. E-TRC is so quick in counteracting any incipient skid that the driver often won’t even be aware of its intervention. Nor will he or she hear the tyre squealing that is often associated with wheel spin.
ECB2 and E-TRC are interconnected with Vehicle Stability Control Plus (VSC+), the world’s most innovative stability control system. It works with the electric power steering system (EPS) to add steering torque assistance to the conventional stability control system, helping the driver get the most out of the car’s performance potential by avoiding stability-threatening situations.Published 26 June 2004