Toyota may have been trailing a few competitors in meeting the small offset barrier test set by the Insurance Institute for Highway Safety (IIHS). But with the new Highlander, it's taken its safety engineering to IIHS's highest rating, Top Safety Pick+. The Highlander becomes the first 2014 model in the mid-size SUV/crossover class to receive it.
The "plus" rating requires Good ratings in four crash tests: moderate overlap front, roof strength, side, head restraint, and a Good or Acceptable rating in the small overlap front. The small overlap test was introduced in 2012 to replicate the left front corner of a vehicle hitting a tree, utility pole, or another car at 40 mph (64 km/h). Highlander was rated Acceptable.
Crash avoidance/mitigation is the "plus" factor and is based on a front collision warning and automatic braking systems to avoid or mitigate the effects of a impending accident. Highlander got an Advanced rating for its optional system.
Body beefed up in front, side, rear
Toyota took many steps in body/frame construction to pass the crash testing, and then went beyond. The left front has a spacer at the bumper, which absorbs and transmits impact energy that's outside of the bumper reinforcement into the front side member. From there it flows into a joining plate at the reinforced front A-pillar area, from which it is distributed up into the roof side structure and down through a rocker panel joining plate into the lower body side structure.
Much of the Highlander forward side structure is made with high-strength steel, with ultra-high-strength steel inserts used in the rocker panel and (as is customary) the B-pillar. The distribution of crash energy through the two joining plates and the beefed-up body structure suppresses body deformation around the cabin from a frontal collision, Toyota said. The two joining plates also are used on the right side.
Side-impact protection includes door impact beams of course, and both the roof structure and floorpan have reinforcing crossmembers that transmit loads to the opposite side in a side-impact collision.
The rear has a collision mitigation design in the form of straight side members and three floorpan crossmembers forward of the rear bumper. The engine compartment hood features a pedestrian protection design--an inner panel that is longitudinally ribbed to provide a crush space above the engine for a pedestrian landing on the outer skin of the hood.
Pre-collision warning, auto braking
The front pre-collision system uses a millimeter-wave radar sensor, a type that is preferred for its image resolution and ability to identify what it "sees" ahead (car, pedestrian, etc.), even at night. It also provides usable readings through fog, rain, dust, and smoke. The Highlander's driving support module is the primary sensor signal collector/processor and its skid control (stability control) module is the electronic "foreman" for the system. The system uses signals from the steering, road speed, and yaw sensors.
If the driving support module decides a collision is possible or likely, it transmits a signal for an instrument panel warning display to flash and a buzzer to sound. It also asks the skid control module to switch the brake assist to a readiness state. If the driver's foot hits the brake pedal enough to trigger the brake lights, the brake assist is activated. This part of the system comes into play at road speeds of 19 mph (30 km/h) and above.
Automatic braking is commanded if the driver doesn't apply the brakes, with a collision possible or likely, a closing speed of 10 mph (15 km/h) or greater, and when reducing engine power wouldn't provide enough deceleration. The skid control module applies the brakes through the anti-lock brakes hydraulic actuator. If the module determines that this won't prevent a collision, and additional braking is needed to further mitigate the crash, it sounds the buzzer for the driver to apply the brakes.
During automatic braking, the driving support module sets a target deceleration rate and continuously recalculates it. If the automatic braking does eliminate the collision danger, the system reduces the automatic application for smooth deceleration and returns to manual braking.
The new Prius also got a "plus" rating, but with Toyota's competitors having moved quickly to achieve it too on some vehicles (other than mid-size SUVs), and a total of 22 vehicles already listed, it's become the "must have" for new models.