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Lexus LS600h L - Driver Aids and Safety
It's at this stage that the LS takes a leap from the sublime, in the form of comfort, to an almost ridiculous display of technical prowess. From a review perspective, it actually presents something of a problem in that regard. Several of the driver aid systems are simply impractical or unsafe to test.
The pre-crash safety system is a case in point. Millimetre-wave radar front and rear, supplemented by infra-red cameras, is used to detect potential hazards. If the system judges that an accident is likely, the suspension and brakes are first primed, followed by emergency steering and braking assist if necessary. It's not something that can be responsibly tested on public roads. The driver monitoring system also detects when the driver's head is turned away from the road for too long and a collision is imminent. These capabilities are backed up by a number of further systems including wall-to-wall airbags and headrests that pop forward to prevent whiplash in the event of a rear-end impact. If you must have a crash, therefore, this car would be the one you'd want to be driving.
Fortunately, the LS also features a number of intriguing driver aids that very much can be evaluated. Perhaps the most famous of these is Park Assist which caters for both parallel and end-on parking bays. Taking the former as an example, the Park Assist routine begins by positioning the LS just beyond the target parking space. Once reverse has been selected, the main console touchscreen displays the rear camera view and the Park Assist menu. Using the touchscreen, the driver must then align a green graphical box over the target space. Next, the driver modulates speed with the brake pedal while the LS handles the steering duties in a single, reverse-in manoeuvre.
The question of how well this all works is complicated. But the short version is that it comes down to how precisely the driver has initially positioned the car itself on the road and then the green box on the screen. The system is very accurate at parking within the green box. But there's something of a learning curve in judging how the location of the green box on the screen relates to reality. It's all too easy, for instance, to set it too close to the side of the road and hence cause the car to inflict some nasty alloy-wheel kerbing upon itself. The whole process is also rather time consuming and therefore not awfully practical for use on busy thoroughfares.
More consistently of benefit is the intelligent cruise control. Courtesy of the radar systems, the LS is able to modulate speed and maintain one of three preset distances from the car in front. It can also detect lane incursions from other vehicles and take evasive action. It's not a full stop-and-go system like the latest offered by some other car makers, including BMW. But it does work right down to extremely low speeds. In our experience, it does a very effective job of lightening the driver's load in both congested motorway and urban driving environments, despite the fact that the system warns that it should only be enabled on multi-lane highways.
Another highlight, pun intended, involves the active LED dipped-beam headlights. The active moniker refers to their ability to swivel as the car is steered into corners, giving a better view of the road ahead. But their most impressive aspect is the sheer clarity and quality of the light produced by the LED lights. It makes the 600h's own halogen high beams look like coal miner's lamps. Frankly, even the xenon headlamps commonly used in upmarket cars seem ordinary by comparison.