> Apparently, motorcycles can
    > brake even if you don't use
    > the brake

They've even made cars with that "motorcycle" feature, it's most commonly activated by moving a sort of "stick" situated between the driver and passenger seat.

'avar' is talking about "engine braking" with a manual transmission car. Most motorbikes have a manual transmission.

If you gear down (you are cruising in fourth gear and 'gear down' to third gear), your vehicle's speed will reduce.

Brake lights are triggered by the brake pedal or lever/pedal on a motorcycle.

In the case of engine braking, the brake lights are not triggered. Drivers behind them can't anticipate stopping without such a signal.

Try it yourself! Some automatic cars, you can gear down, or just pull your parking brake a little. Cars behind you will come dangerously close to hitting you. Also, don't try this.

Wait, do new cars' parking brakes trigger the brake lights? I also wonder about regenerative braking in electric cars where they slow down simply by lifting your foot off the accelerator.

Lifting your foot off the accelerator in a Nissan Leaf triggers brake lights when in e-Pedal mode (one foot driving, no need to use the brake pedal except in an emergency). It reminds me of a feature that car manufacturers declined to install (due to cost) many years ago, in which brake lights would be triggered by rapidly taking your foot off the accelerator. The idea was that this scenario would usually be followed by emergency braking and that anyone following would see the brake lights come on a fraction of a second earlier.

> it's most commonly activated by moving a sort of "stick" situated between the driver and passenger seat

It's not even specific to the ones with the stick. I happen to enjoy and prefer vehicles with three pedals, but I can say from personal experience that a Ford AODE, 4R70W, or 4R100 will hit hard enough to scare passengers when you drop a gear at highway speed.

A Chrysler 45RFE on the other hand will make a lot more noise but basically no braking effort when you downshift.

Weirdly, this happens with every vehicle as soon as I take my foot off the accellerator, except when it's downhill.

(kidding. IIRC EVs do regenerative braking (and trigger the brake lights) when you lift off the accellerator.)