One of my favorite features of the Model S is regenerative braking. Engineers have been using regenerative braking for decades in trains, trolleys, cars, even motorcycles. A very short and hopefully simple explanation can be found on Wikipedia.
Regenerative braking is an energy recovery mechanism which slows a vehicle or object down by converting its kinetic energy into another form, which can be either used immediately or stored until needed. This contrasts with conventional braking systems, where the excess kinetic energy is converted to heat by friction in the brake linings and therefore wasted.
When you take your foot off the accelerator of a Model S it immediately begins to slow down, almost as if you were applying the brakes. But instead of wasting energy, it puts it back into the batteries for later use. I have gotten quite adroit at using the regenerative braking system. Most days I drive my entire commute without ever depressing the brake pedal. This one pedal driving is fantastic but takes some getting used to. You need to train your mind and muscles that not moving your foot to the brake pedal can slow down your car. One point of caution. Your foot is hovering over the accelerator, not the brake pedal. If you want to stop the car you need to press on the brake, but it is actually the accelerator beneath your foot. After a 3 or 4 days of driving the Model S, you will be accustomed to this new way to driving.
Of course it’s nice to know that the Model S is equipped with a 4 wheel ABS disc braking system as well as an electronic parking brake capability that can be applied with a simple press on the end of the gear stalk. Being able to stop in any vehicle when you need to is obviously important. Tesla has not ignored that, only enhanced how to stop your car.
I apply my brakes only about 10% to 20% of the time in the Model S as compared to other cars I have owned. It’s quite possible I will not need to replace my brake pads for as long as I own this car. Another significant cost savings.
You can turn off the regenerative braking feature in the controls section on the main touchscreen display. If you want to drive it like a gas car you can activate the “creep” mode. Your Model S will then disguise itself as an internal combustion engine by requiring you to depress the brake to slow and stop, as well as move along every so slowly when you release the brake pedal when you are stopped.
Regen braking is not a substitute for normal friction-based methods of slowing and stopping a vehicle. For safety, Tesla programmed the software in the Model S to illuminate the brake lights when the accelerator is released to alert drivers behind you that you are slowing down. If you live in a colder climate where there can be snow or ice on the roadway, It is advisable to turn off the regenerative braking and drive the car the way you would any other.