Say your accelerator jammed

It is possible that the Lexus has some engine protection system that would not allow you to put it in neutral while the throttle is fully open; neither would it allow you to brake as that would not make sense and the brakes could overheat.

Yes, it was a dash for fame, as was the one with the trucker in the Scania. But in either case, turning the ignition off wouldn't lock the steering, removing the key would. The trucker later turned out to have some syndrome or other.

Steve

Stand on the brake pedal, turn the engine off then. If you push the brake pedal it will still stop. Try it.

If it was wired up to compare the throttle & the brake then the brake would win.

Then let's hope they don't have pedal jamming issues. They could be sued for millions, if they make it impossible to slow the car.

I don't own a Lexus, but some have replied that the engine would override the brakes since you're not supposed to brake at full throttle.

Some people make all sorts of odd claims.

That would be a nonsense. Since it will be drive by wire the brake should cancel out the throttle as the safer option of the two.

But cars are becoming more like robots these days. I think Volvo has a system which automatically brakes the car to keep distance from an object in front of the car. That would have solved the problem. (unless there was a sign bug in the computer code... :)

Such stories somewhat predate that though, see Audi or Saab & unintended acceleration.

Yes, should do...

Anybody with a driving licence ought to be trained in steering the car when the power steering is without power, so to speak, and when the brakes have no assistance. Just as a simple emergency drill.

It would rev into the red zone, but there is probably a rev limiter somewhere.

Are there cars that don't? Things like BXs and Xantias use the hydropneumagic system, but the likes of C5s use conventional systems with vacuum servos and DOT brake fluid.

I've driven a couple of old Polos without servo assistance fitted, and a couple of 1990s Diesel Peugeots with leaky hoses from the vacuum pump. The brakes feel like they are made of wood.

Some Mercedes, & as you say Citroens. There's a load of American stuff that used electric pumped hydraulic boosters, cadillacs spring to mind.

my sierra has no servo, it has an electric pump instead.

I thought this was the case with most modern cars fitted with ABS.

There's normally both, you can pull the fuse on the ABS & still have a servo.

I don't do much on my modern car myself - it's a BMW - but I can't see any sign of a servo under the bonnet. On my SD1 it's huge, and mounted on the master cylinder.