What You Need to Know About Park Assist

Last Updated: Mar 14, 2013

What is park assist?
Park assist tells you how close your car is to any stationary object, thereby making it easier to park in tight spaces without hitting other cars, parking posts, walls.

Park-assist systems use a series of bumper-mounted sensors and primarily employ ultrasonic sound waves, though some use radar or lasers. The sensors relay information to you by sounding a series of beeps or using a visual display on the instrument panel. Many systems use both lights and sounds to help you judge the distance between your car and a stationary object. As you get closer to an object, the beeps become more frequent or the visual display’s lights will go from green to yellow to red depending on how close you are to an object. Once the system has determined your car cannot get any closer without possibly hitting the object, the beeps turn into one long tone and the warning lights flash or turn solid red.

A basic ultrasonic park assist system has three or four sensors mounted across the rear bumper. It’ll use only an audible warning and work only for the rear of the car.  On some mid- to high-priced vehicles, there are sensors in the front and rear bumpers and they may even have sensors on the corners of the bumpers to further help with parallel parking. These visual displays often take the form of a small graphic outline of the vehicle with lighted bars around it to help you judge more precisely the distance between your car and a stationary object. Because park assist can be annoying in certain situations, like in the drive-thru at a fast food restaurant, the system can be turned off, usually by a dashboard button.

How does park assist help me and my passengers?
Take a look at the bumpers of cars parallel parked on any city street. Even expensive cars have dinged and scratched bumpers. For some drivers, that’s just as it should be: after all bumpers are for bumping. But if you don’t like bumping and scraping by in tight situations, park assist is probably worthwhile for you. Get it and you could save hundreds of dollars on bumper or taillight repairs alone. Park assist can help your passengers because they’ll never again need to get out of the car and guide you into a parking spot by shouting or using hand signals.

Even skilled parallel parkers can benefit from rear parking sensors. Basic systems can help you make the most of the few parking spaces on a crowded city street. A system with parking sensors in the front bumper is a step up from the basic. This setup is helpful if you park head-in against a wall in public parking garages or if at home you have to pull close to the rear wall to be sure your garage door closes. Park assist is also a great option on large vehicles or on vehicles with limited visibility, such as SUVs, pickup trucks, or vans. Coupes or sedans with high-set trunk lids or a sloping rear window are great candidates for parking sensors too. The shape of those cars can make it hard to judge distance in tight parking situations. Park assist is also a good feature for older drivers who may have limited mobility or back and neck pain that makes it difficult to turn all the way around when backing into a parking spot or out of a driveway. 

Is park assist a must-have on my car?
Park assist is not a must-have feature for most drivers. It’s more like a nice little extra. However, if you frequently park on the street in an urban area or in other tight spaces it’ll make parking a lot easier.
Some mid- to high-priced new vehicles include park assist at no extra charge. For example, the 2011 Ford Edge costs about $30,000 and rear park assist is standard even on the SEL model which is one step up from the base SE version. Even when park assist is an option, it’s not very expensive. On some vehicles where it’s a stand-alone option, the cost is about $350. The 2011 Buick LaCrosse offers rear park assist as part of a driver convenience package that also includes automatic-dimming mirrors, power heated mirrors with integrated turn signals and memory linked to the power driver's-seat memory. Even so, the package adds only an extra $550 to the price of the 2011 LaCrosse. Park assist has been around in passenger cars for more than a decade so you’ll find many moderately priced used cars equipped with it, too.

Ultrasonic park assist is the lowest cost system and what you’ll find on most new cars and trucks. It does have limitations, though. Because of the cone shaped pattern in which the sound waves are sent out, an ultrasonic system may miss small objects or those that are very low on the ground. Radar-based systems do basically the same job as ultrasonic setups but are more accurate -- and more expensive. For example, the 2011 Mercedes Benz E350 has optional front and rear parking sensors that incorporate radar as part of the system. It’s included in a $2,650 option package that also features adaptive cruise control.

Carmakers often pair park assist with other parking aids, such as a rearview camera. This uses a video camera to display on a dashboard monitor or a portion of the inside rearview mirror an image of what’s immediately behind your car. Some cars also have front-view cameras that serve the same purpose. These camera systems can also employ the warning beeps of park assist as an extra layer of safety. Park assist is not the same thing as a rearview camera. And park assist is different than automatic parking system that essentially helps the car park itself.
The bottom line of course is that no matter how much technology automakers stuff into the modern automobile, many of the old principles still apply.

When backing up, turn and look over your right shoulder, and when pulling into a parking spot, always take the last few feet slow enough so that if you do hit something, it won’t do any real damage. Park assist can be a big help when parking in tight spaces. But it’s just that, a help in judging the available space between your car and another object.