2010 third generation Toyota Prius. My wife and I are experiencing unpredictable momentary brake failure and sense of loss of control of this vehicle. This occurs unpredictably under various conditions such as uneven pavement, pot holes or patches of slippery road surface. The loss of braking force is brief, but the resulting reengagement of the brakes can be harsh and startling and has created moments of erratic and dangerous control lapse. This pattern of brake failure has occurred by my guess greater than 20 times since our purchase of the vehicle approx 4 months ago and over the course of 10,000 miles so far driven. Over all we are very pleased with this vehicle, but are concerned that this braking unpredictability and abrupt reengagement will eventually be the cause of an accident.

- Silver Spring, MD, USA

Braking problem on 2010 Toyota Prius. Vehicle surges while applying the brakes on a bumpy road. I have experienced this on several occasions since purchasing the vehicle new this year. The vehicle has not been taken back to the dealership at this point in time.

- Marietta, GA, USA

I own a new 2010 Toyota Prius. I have always suspected the brake has problem. It happened several times that the vehicle will surge forward on slippery, uneven surface or pot holes when I hit the brake.

- West Windsor, NJ, USA

2010 Prius brakes do not work properly when hitting a slick manhole cover - car actually lunges forward. Seems to be a software glitch when regenerative braking is taking place and one or more wheels can slip on the road surface.

- Cincinnati, OH, USA

I own a 2010 Toyota Prius. During the five months I've had it, I had 3 to 4 encounters with brake problem. Twice I was driving around 20mph and was braking and preparing to make a turn, but the brake failed to work, and I felt that the car was accelerating out of control. This lasted for only about a second, and I eventually was able to slow the car down and make the turn. In one case the road was very bumpy, in the other case the car hit a pothole right around the time I braked. On a third incidence, the brake didn't work for a second on a slightly icy, slippery highway, when I was going at around 30mph. This may suggest that the brake function poorly on slippery road, although I haven't had another chance to experience this again.

- Fort Lee, NJ, USA

I bought a 2010 Prius on 7/25/09 and shortly thereafter noticed something a bit unusual with my brakes at sporadic times. I just now read the description someone gave in an article about trouble with 2010 Prius brakes and it fits my experience to a T: "when braking, if a pothole or bump in the road is hit, the car seemingly jerks forward/accelerates for a split second." In addition, on sporadic occasions when backing up the brakes will grab sharply when relatively light pressure is applied. As for a date below I have listed today's date as it occurred today, but has done so intermittently since I have owned the car.

- Richardson, TX, USA

2010 Prius - braking effectiveness is lost on rough surfaces. The car gives the sensation of lurching ahead. In addition, we have experienced surging problems when using the cruise control. Rather than accelerations to the preset speed, the acceleration continues past the setting until the cruise control is canceled by tapping the brakes.

- North Canton, OH, USA

My vehicle surged forward or temporarily lost braking after driving over a pothole or other uneven surface, and this is a recurring problem.

- Worcester, MA, USA

Brakes did not work on ice. Car went forward about 15 feet with no brake action.

- Plymouth, MN, USA

Brake not responding when applied.

- Columbai, MD, USA

My 2010 Prius has twice had a brief momentary loss of braking in slow speed. Both times this occurred when trying to stop for a stop sign in a residential area with low speed and on icy/snowy surface. The vehicle stopped 5 feet or so past the originally intended point of stopping.

- Ham Lake, MN, USA

Brakes locked up when gently pushing on pedal at low speeds in forward and reverse, anti lock brakes engage while stopped if your foot wiggles on brake pedal, brakes do not engage strong if you hit a small bump while braking causing you to not stop on target and anti lock brake symbol briefly flashes on at the same time.

- Galveston, TX, USA

I thought that it was just me but when I heard others complaining about the brakes on the new 2010 Prius I confirmed what I have been experiencing. Whenever I begin to brake and either (a) hit a bump or (B) begin a turn, the car jumps or lurches as if losing traction for an overly excessive amount of time leading to a short but significant loss of control.

- Dallas, TX, USA

2010 Toyota Prius - odd braking behavior. On a number of occasions, when the vehicle is completely stopped and the wheels are not turning, when I press on the brake pedal, the orange "skid warning" indicator on the instrument cluster turns on. Something is wrong when I get such a warning, as the vehicle is not moving, and certainly not skidding.

- San Francisco, CA, USA

The contact owns a 2010 Toyota Prius. Whenever the contact attempts to brake traveling over a rough terrain at a low speed the contact noticed that the brakes will suddenly disengage and then correct itself. The vehicle has not been diagnosed by the dealership and there were no prior warnings. The current and failure mileages were 5600.

- Nashville, TN, USA

I bought a 2010 Toyota Prius on Dec. On 12/21/2009, and have noticed on at least 4 occasions that when I brake on top of a bump in the road, the car actually lurches forward, instead of slowing down and stopping. I thought it was just me, but then I heard a story about it on npr, and now feel that this problem has been confirmed by others. I have been lucky that on the occasions when it has happened, there has not been a car in front of me, or I might have hit them from behind.

- Coconut Grove, FL, USA

I was driving my 2010 Prius and approached a stop sign at an intersection on a local road. (as I approached the intersection I was probably driving about 20 mph or less). After I hit the brakes and had been decelerating for a very brief period, I went over a pothole or some similar protrusion. At that point, my car lurched forward, almost hitting another car. That car had been about half car length in front of me when I hit the pothole.

- Bethesda, MD, USA

While I was driving in city traffic and braking firmly as traffic slowed, one or both of my right-side tires passed over a manhole cover or hit a shallow pothole (this has happened several times). Braking effort completely stopped for a second or two -- the car felt as if it were surging forward, but this was probably just the change from deceleration to coasting. Braking resumed, either automatically or following increased pressure by me on the brake pedal, I'm not sure which. No collision resulted, but one easily could have if I had been following another car even a few feet closer than I was.

- Denver, CO, USA

Braking power suddenly gave out momentarily. This occurred at low speed. However, I was approaching a crosswalk with a pedestrian in it. If felt like the car lurched forward. I read the article in the nyt this morning which noted this problem with the Prius and this definitely fits my situation. It does not happen frequently (3 or 4 times at most), but it is obviously a safety issue. I purchased my 2010 Prius new on Nov. 3, 2009 from Toyota of seattle. I contacted the dealer about this issue a few days ago, but have received no response.

- Seattle, WA, USA

2010 Toyota Prius frequently accelerates briefly when braking after hitting pothole or going over a bump. In addition, frequently at start up, the brake pressure is extremely high, and the slightest release of the brake causes the car to lurch rapidly either forward or back, depending upon whether in drive or reverse.

- Santa Monica, CA, USA