[cartoonworld]

Thats the same case with all brakes in use more or less. Also modern brakes have two hydraulic systems, in the case that one of the loops (front or rear) breaks there should be sufficient pressure to apply the brakes still.

Sometimes its front/rear and sometimes it is diagonal, but it should still do the emergency trick.

[giantg2]

Regular parking/emergency brakes use a cable instead of hydraulics.

[cartoonworld]

They also don't really stop a moving car, its a parking brake.

Just wanted to add, a EPB used for emergency stop in his scenario is just using the regular stopping brakes, its not an emergency brake either.

[Denatonium]

What cars is this the case in? All the cars I've ever driven have hydraulic-assisted brakes but can still be used without the assist in a pinch, if you really use your leg muscles. It seems REALLY dangerous to have no ability to manually actuate your brakes. If an ICE car like this with an electronic parking brake were to stall while going downhill, you'd be completely screwed.