[centexan]

If it happened to me I would first downshift to the lowest gear I could, then put it in neutral, and finally cut the engine off (but not remove the key.) I now know you can’t downshift a Prius but I haven’t heard anyone else talk about this - how fast can you go in a 2000+ car in first gear?

[Erik Latranyi]

If it happened to me I would first downshift to the lowest gear I could...

It doesn't have gears like a conventional transmission.

[Crolis]

I think the Prius uses some type of continuously variable transmission (CVT) in their “Synergy Drive”. I have a CVT in my Ford Freestyle and it was wierd at first to not feel the gears change. I do have a ‘L’ marker on my shifter to tell the transmission to use a lower gear ratio, but I’m not sure how the Prius software handles that. The ‘B’ mode I think is what they call the engine braking/low gear mode.

Of course, if the software swiches to an unstable/unpredictable state, it sounds like all sorts of problems arise.

Too bad they didn’t place a covered emergency override switch which could trump the computer. Similar to a “limp home” mode some cars have where the override would force the car to set parameters which would limit top speed to 10mph and restore operator controls.