New Lexus LS helps park itself

That longtime favorite of futurists and sci-fi fans, the self-driving car, is about to come one step closer to reality when Lexus introduces its all-new LS 460 sedan later this month. The optional Advanced Parking Guidance System (APGS) enables parallel-parking-challenged drivers to safely sidle up to the curb. We recently had the opportunity to sample the system on a new LS 460 and its elongated version, the LS 460L. Remarkable as this new technology is, like a lot of high-tech wizardry, it may not be totally ready for prime time.

APGS works by using a back-up camera, sonar sensors, and electric power steering to guide the car into the space. The somewhat complicated process of parallel parking begins with stopping the LS sedan when your driver's seat is alongside the rear bumper of the car just ahead of an available parking space. Next, you roll forward until your seat is next to the front bumper of the other car. Then, holding the car in place via the brake pedal, put the car in reverse. A dashboard screen displays a video image of the target space, along with the cars in front and behind, with the space outlined in green. There's a choice between parallel parking or row parking, which you have to make on the screen. You then move a flag on the screen to a position next to the rear bumper of the car in front. Then you press "OK". Now, you can sit back and modulate the brakes while the car "automagically" steers itself through the reversing maneuver. Watching the steering wheel twirling by itself in front of you is quite an eerie experience. The system audibly announces its work is done, and all the driver has to do then is shift into drive and center the car in the space.

The system sounds helpful in theory, but the overall effectiveness is limited by numerous fail-safe measures. For example, if the driver touches the gas pedal while APGS performing its task, the system shuts down and leaves you to park on your own. While it's probably not a bad idea to discourage high-speed parking, the safety override prohibits enlisting the services of APGS on any surface with much more incline than a billiard table. On flat surfaces where the LS 460 can idle its way up to several miles per hour, it is necessary to apply sufficient brake to keep the car at a crawling speed APGS is comfortable with and clearly, more braking is needed when backing down a hill. Too fast, and once again, you're parking yourself.

Then there's the way APGS reads its target. During one experiment, we ended up neatly parked squarely between two cars, each more than a foot from the curb. Why so far away? The car in front of us was 15 inches from the curb and APGS uses the flanking cars to position itself. The driver can make some adjustment to where the car will end up by moving the flag on the video screen, but the instructions indicate the flag should be positioned at the rear bumper of the car in front. And speaking of the cars in front and behind, unless the space you've chosen is at least 6.5-feet longer than the LS 460, the parking space you chose doesn't qualify so keep looking for a spot. APCS is just as intimidated by a tight space as some of the drivers who need its help.   

Another key concern is the time it takes to simply operate the system, and patience is in short supply on city streets. While it takes but a few seconds to properly position the car, make any target adjustments on the touch screen, and let APGS rock and roll, seconds count. APGS will never be as quick as a grizzled, veteran city driver--the kind who is likely to steal your space or blare their horn while you're still fiddling with the touch screen.

To be fair to Lexus, some of our clumsiness with APGS can be chalked up to inexperience, and the system's limitations are not entirely their fault. A Lexus tech rep confirmed the technology exists to enable the car to perform a parking maneuver start to finish without the driver doing a thing, but as is often said, we are a litigious bunch here in the United States. APGS is very deliberately designed to make sure the driver stays involved in the process.

APGS will be a learning tool for some drivers; watching it work may even teach some drivers how to parallel park. But when it's time to pull out into the street, they'll just have to figure that out on their own.

APGS will be offered as part of an option package; prices have not yet been set.

--Jim Travers