Sudden Burst of Speed

was stopping because of the red light... i don't think so it was really strange and it happened twice on the same intersection(spot).

 

I don't know about you guys, but I don't think my Prius has had a burst of speed intended or not...more like a lazy inclination to proceed forward...haha

 

I had the exact same problem.

 

sudden acceleration happened to me again.

 

Was this at the same intersection? Going the same speed?

 

That happens to me every time the light turns green.

 

a different intersection, hit a bump on the road and as i was slowing down with my foot on the brake pedal it just accelerated a split second.

 

It doesn't accelerate in this situation. Simply put, the deceleration lowers or stops for a split second, which feels like forward acceleration. Humans have an amazing ability to establish baselines and notice any difference. In this case you adjust to the feeling of deceleration. When it drops or stops, it feels the same as accelerating in the forward direction, even though your speed doesn't increase.

Tom

 

Guys, everyone seeing this issue, read this. It's accurate. It covers every single instance reported in this thread. Thanks Tom.

 

Yup. It is "sudden loss of expected deceleration", not actually "sudden acceleration". It is nevertheless highly disconcerting and more than a little disappointing. It feels like a sudden jump forward and it freaks out every single driver to whom it happens. Call me a concern troll if you'd like, but I don't see how a behavior that freaks out every driver of the car can be considered ok. I'm amazed this behavior has managed to survive so long without being changed. I won't trade my car over it - I love my Prius - but it still stops my heart every time it happens and I sure wish it would quit doing it.

 

I completely agree. There are numerous threads on this issue and, apparently, it happens with other makes and models as well. I understand Tom's explanation (sort of) but has anyone verified that the vehicle stops at the intended stopping point as long as you don't freak out and remember to press harder on the gas pedal? I'm pretty sure I overshot the intersection by a couple inches at least when it happened to me last time and another driver reported that he missed his turn because of it.

Are we just freaking out or does the car really travel farther than the driver intended, no matter how quickly one reacts? If it does, then it's a major safety issue.

As the weather gets colder, I'm starting to dread braking on icy and snowy roads. With all of the local towns and cities facing debt, there won't be much plowing, salting, or pothole repair this season!

Chris

 

Well, if you think about it, a "sudden loss of expected deceleration" would have pretty much the same effect on your stopping point as a "sudden acceleration". Either way, you didn't get as much deceleration as you were planning on, so it seems pretty likely you will overshoot your mark. Now hopefully, you react by pressing the pedal harder and make up for the loss of deceleration. But you do have a reaction time of at least a tenth of a second, and during that time, you are going to travel some distance. I suppose it really all depends on the exact circumstances, but I certainly have no trouble imagining a situation where it could actually be a problem.

 

Loss of braking action is always a potential problem. The situation described in this thread is just one of many ways that braking can take longer than expected, which is why we leave extra space in front of our cars.

Tom

 

I like that term, I think I'll borrow it.

Wayne

 

Most drivers would instinctively slow down for pot holes to avoid suspension/wheel damage.

 

Common procedure for those potentially "slick" situations is to slow before the spot then drive through it. You generally do not brake on the surface which is what Donee said you should avoid doing.

 

finally this issue(problem) is going to be addressed. :thumb:

 

I experienced exact same thing and posted to this forum a while back. Best guess after much discussion is that cruise control stalk unwitting hit my leg - this can cause RESUME function, which could cause hard acceleration, and would cut out upon firm braking. Since you were turning right, it could possibly be the cause of your episode (check out the layout). I have definitely had the stalk hit my leg at least once since, but I now typically avoid turning on the cruise system due to this safety design flaw in the layout. Fact that I am 6'2" and my wife adjusts the seat very different from me doesn't help...