Let's take "on the road" literally. How far are we away from driving an autonomous car on public roads?

In 2004, 2005 and 2007, DARPA asked researchers to create driverless vehicles in its Grand Challenge and Urban Challenge races. Several vehicles came close to what we could perceive as an autonomous vehicle, even if it was clear that the technology used in all cars would have to mature, along with a new idea how traffic can be managed.

Several years later, consumers can purchase especially luxury vehicles with a truly overwhelming number of gadgets, some of which appear to be going the route of the driverless car. If you head over to luxury manufacturer websites, you will find features such laser- or radar-guided active distance cruise control, complex camera systems, advanced navigation systems as well as lane departure warning systems that are evolving to be much more than passive tools that simply warn drivers of particular dangers. They are now actively participating as an assistant driver. A few videos on Infiniti's website are especially enticing as they suggest that such technology may be able to drive your car (almost) by itself. Can it?

We asked for a decked out Infiniti to give it a try. The manufacturer gave us a loaded-to-the-gills QX56 4WD full-size SUV with the $2850 technology package that includes intelligent cruise control, blind spot warning, distance control assist, lane departure warning as well as intelligent brake assist and a forward collision warning system. While this package appears to be a bargain, it's not a particularly cheap car. The base 2011 QX56 4WD stickers for $59,800. Our version came with the $2450 theater package, the $5800 touring package, as well as $900 illuminated kick plates and $320 roof rail cross bars. Including $950 destination, this QX56 sells for $72,560 MSRP.

All (assistant driver) security features are disabled by default, while the QX56 always warns the driver of a possible collision or an accidental lane departure via a warning sound and objects in its blind spots via a visual signal. Before I jump to the active features, I have to give Infiniti's/Nissan's engineers kudos for a fantastic navigation system that is seamlessly integrated with the car and works amazingly well with the camera system that, thanks to cameras on all sides of the SUV, provide a great bird's eye view of the vehicle, which is appreciated when maneuvering a monstrous car like the QX56 in tight spaces.

The active driver assistance systems are activated via three buttons on the steering wheel: Basic cruise control, intelligent cruise control and lane departure warning as well as lane departure prevention. The distance control engaged a radar system that is built into the front bumper and slightly fans out horizontally with a total reach of 390 ft. The desired distance to the car in front of the QX56 can be set to one, two or three car lengths. Activated lane departure is designed to react when a line on the street is crossed as long as the steering input is less than 2 degrees and there is no turning signal set.

On the road, the distance control will immediately react once traffic slows (or accelerates) in relation to the speed set in the cruise control system. If traffic slows, the QX will slow as well to keep the set distance. If needed, the vehicle will brake to a full stop and resume to the cruise control speed when traffic speeds up again. However, the system automatically disengages at stops that last longer than 2 seconds, for example at traffic lights. During my test, the system worked well and reliably in a default pattern, but I noticed that it could be confused when cars were cutting in front of me and it did not react quickly enough to remain in my comfort level to avoid a collision. It may have avoided the collision, but I was surely not motivated enough to find out.

Interestingly, the same effect surfaced when a car directly in front of me suddenly left the lane to the left or right. It seemed as if the QX' system did not recognize the next car ahead of it fast enough as system reacted with sudden acceleration that was too strong for the general traffic pattern. On other occasions, I felt the acceleration from a dead stop was not fast enough and tested the patience of drivers behind me. However, the overall feature set is almost spooky in its default design and inside a constant traffic pattern that reacts in emergency situations that are caused by a driver who may be really too tired to safely drive. There is the clear impact that the SUV can flow in traffic without too much interaction of the driver.

The lane departure system works in a similar way. It requires clearly painted lane stripes to function and if you accidentally cross either line, the QX will automatically slow the two wheels on the opposite side to pull the car back into its lane. Depending on the angle, the system works less or more aggressive, but avoids that the car is swirling into the wrong lane and cause a head-on crash. However, once it is pulled back (without a significant slowdown of the car), it is unlikely that the QX will not run over the lane on the other side - at least I was not confident enough to give that a try in the Chicago suburbs, where road quality is mostly so poor that this system would only react (to the right side of the street) when I am already driving in gravel and landed halfway in a ditch.

The conclusion? The technology in the QX56 is impressive tech and a demonstration how security features in cars are evolving. Can they keep you on the road by themselves while you are sending emails from your phone? No. However, that is not what they are intended to do anyway. Brian Brockman, a spokesperson for Infiniti, told us that that both lane departure warning and distance control features are designed to keep the driver engaged in the driving process. "We do not want to take the control away from the driver," he said.

In the end, keeping the driver involved is a safety feature in itself: "You really need to be attentive to traffic, our systems act only as assistants."