When was the last time you sat down and had a heart-to-heart talk with your accelerator pedal?

I recently had a wonderful chat with the pedal of a BMW 5-Series prototype on a Continental test track near Frankfurt. It read a speed-limit sign and noticed I was driving too fast, so it gently prodded me to slow down.

It helped me improve my fuel economy by signaling with a slight ticking the optimum time to up shift.

The pedal also guided me through a simulated intersection by noticing the traffic light was about to turn red and applied some upward pressure. When the light turned green and traffic started to move, it relaxed.

It also helped me keep the right following distance from the car ahead by occasionally nudging my foot when I got within tailgating range.

When I was cruising along daydreaming, and potentially about to ram the car in front of me, the pedal suddenly pushed back hard and thumped, grabbing my attention faster than an audible or visual alert.

Our conversation was informative, but most importantly, it also was simple, intuitive, unobtrusive and private. Very unlike the buzzing, blinking, vibrating and generally annoying alerts of so many other new devices designed to improve vehicle safety.

The pedal officially is called an Accelerator Force Feedback Pedal, or AFFP. An electric motor is linked directly to the pedal and is capable of delivering haptic feedback within tenths of a second. It can deliver all manner of information based on inputs from the vehicle’s forward-looking radar, traffic-sign reading cameras, vehicle-to-vehicle and vehicle-to-infrastructure communications.

This new pedal is the new face of the human-machine interface.

Ward’s editors have tested pedals with haptic feedback from different suppliers in a variety of cars, from hybrid-electric vehicles to the imposing 420-hp Infiniti M56 luxury sedan. In those cases, the pedal feedback felt gimmicky and stubborn, and was not well-liked.

It is the greatly enhanced sensory inputs that won me over with the Continental prototype AFFP.

Even so, it’s likely many drivers still would be put off by the device, because they don’t like communicating with their car through foot massages.

Someone else might prefer a vibrating steering wheel, signals on a head-up display or a special series of lights and chimes. Another might respond better to the voice of a favorite celebrity telling them what to do or not do.

For years, we have considered the HMI to be a knob on the console, or a screen and some buttons on the center stack.

But with swiftly advancing sensor, camera and haptic technology, the HMI can and should be the entire vehicle, not a specific grouping of buttons or displays.

And the interfaces should be customizable, so drivers can choose the mode in which they interact with their vehicle.

Someday, perhaps, you could start your car with a few special taps on the hood, or by petting the instrument cover like a family pet.

Whatever the case, auto makers must continue their efforts to expand the HMI beyond the center stack to allow the driver to eventually interface with the entire vehicle, not only through visual, audio and tactile feedback, but sensory areas not yet explored.