In the "good" old days there were several things you could do: - turn off the ignition (now purely software-controlled in keyless systems) - put transmission

In the "good" old days there were several things you could do: - turn off the ignition (now purely software-controlled in keyless systems) - put transmission to neutral (a physical link doesn't necessarily exist anymore in automatic transmissions, still possible in manuals) - jump on the brake pedal as hard as you can (I suspect that a hydraulic link to brakes must still exist, possibly by law, but there are ABS and stability control units in between that can add to or remove from the brake pressure so it's not entirely driver controlled anymore, could lead to a failure path) - use parking brake to assist in braking (now often controlled by an electric motor automatically, doesn't engage while driving) There were occasional similar failures like the accelerator pedal getting stuck under the floor mat or throttle cable getting stuck but you could do a number of things listed above. Cruise controls systems were heavily designed to disengage at the slightest disturbance because they were separate control modules: early vacuum-operated designs could—plausibly, I don't have first hand knowledge—have a microswitch in the brake pedal that would just pull a relay to shut off current from the control module, restoring normal accelerator operation. Pretty much bullet proof. Software is indeed capable of creating failure modes that were pretty much unimaginable previously.