The first time I heard about driverless cars sporting red license plates with a sci-fi-esque infinity sign slinking about the roads of Nevada, I thought they were pretty cool.

And then I thought about it some more.

I am, after all, a horrible passenger to the best of drivers. (Yes, I'm the type that hits the invisible brake from the right side of the car.) How would I feel to see a car go by with nobody home? Could I pack my kids into one? And – good grief – could I let one take me for a spin? I'm not so sure.

It turns out I am not alone. In fact, the majority of adults polled by Harris Interactive said they would be nervous in a vehicle sans pilot. About 79% were concerned the vehicle would fail while on the road; another 59% said they'd be worried about liability should a driverless vehicle have an accident. Steven King's Christine had nothing on the next scenario that chilled 52% of adults polled: hackers assuming remote control of their vehicle. Yikes!

It's Google (GOOG 0.37%) (GOOGL 0.35%) – not the automakers – leading the charge to get prototype robo-cars on the road. The "red tags" have been seen in Nevada since 2012, and driverless test vehicles could be on the streets of California by June 2015. Should they pass safety tests, Google plans to roll out about 100 prototype vehicles to California drivers without pedals or steering wheels. Slightly roomier than a moped, and not as fast, the test cars will have two seats and a maximum speed of 25 mph.

It seems that a fully functional robo-car may be many years away. Nevertheless, the bits and pieces of the technology that will make these vehicles a reality are mainstream right now; in fact, you may be driving a partially driverless car today.

The automakers take the wheel

Cruise control – now old news – was a huge stride forward for the driverless car. This now nearly ubiquitous feature was one of the earliest forms of Advanced Driver Assistance Systems (ADAS) to go mainstream. But consider the ADAS ground that's being broken by the major automakers in the name of safety and efficiency that are – not so coincidentally – conditioning us to give up some control while at the same time moving technology toward those driverless wheels of the future.

General Motors (GM -0.05%) offers a wide range of ADAS features, most notably in its Cadillac brand. While pricey, features such as front collision alert, lane departure warning, adaptive cruise control, emergency mitigated braking, cross-traffic alert, and blind spot monitoring give a heavy assist to the human driver.

Meanwhile, Ford (F 0.17%) has unveiled its wireless vehicle-to-vehicle communication technology. This will work in conjunction with ADAS systems and allow cars to interact with each other to detect – and avoid – potentially dangerous situations. The systems will warn drivers if there is a risk when changing lanes or going around a blind corner, for example.

But what about parallel parking?

Now that I've confessed that I am a horrible passenger, I suppose it doesn't hurt to add that I cannot under any circumstances parallel park. I love the concept of a car that will parallel park for me, but does that mean I would trust it?

Lexus, Ford, Land Rover, Nissan, and Mercedes-Benz – to name a few – offer varying levels of parking assist that should appeal to me and my similarly challenged friends. This one feature employs a whole range of ADAS features, including cameras and sensors, but still requires driver intervention. Most systems will engage when the driver says "find me a spot" and then alert the driver when there is space enough to park the car. The car will then trade various levels of control with the driver until the car is seated a respectful distance from the curb. During testing by USA Today, many of the systems were able to parallel park faster than average drivers, but could still be outdone by parallel parking pros.

When it comes to parking assist, I like the idea of help ... but the car would have to earn my trust before I relinquished control downtown during rush hour.

The technology of tomorrow, today?

While Google is out garnering headlines for its driverless car prototypes, it would seem that the real revolution is happening in our driveways. With all the ADAS features in use today and new ones on the horizon, it may well be that the driving public will have moved way down the road to acceptance by the time a fully pilot-less vehicle is ready to roll mainstream.