I have experienced at least three times in my 2 month old 2010 Toyota Prius a lurch forward when braking when my car drives over a bump, pothole, or something slick. Most recently I was driving downhill in dense traffic and the lurch felt like an acceleration. I had to slam on the brakes to avoid hitting the car in front of me. This braking problem clearly can be a hazard to safe driving and to any pedestrian or other close vehicle.

- Seattlew, WA, USA

When the car goes over an uneven or bumpy [surface, ] or down an incline, the car accelerates or lurches forward. This has occurred several times and is unnerving to the point I have switched cars with my husband. Also, when coming out of my garage most each day, the car rolls back on battery power, but the brakes are stiff, just liked you would pump them when the car is off (real hard) until the cars motor turns on. But by then, you have rolled 15 or so feet backward with little to no break control. They feel like they won't stop the car.

- Somerset, NJ, USA

2010 Prius. This has happened about 10 times now. Sometimes when I brake, I experience a sudden acceleration. It ranges from slight to a lurch. When it first happened, I thought it was something on the road and ignored it. When it was more pronounced and happened a couple of more times, I brought it to the dealer. They said they had no other reports and could not replicate it. The service manager took me on a test drive and the car was fine. I knew this would happen as the acceleration is only occasional. I was advised to call Toyota national, which I did, and was told that since this could not be replicated that there was nothing they could do and no recourse I had as the complaint could not be replicated. It has happened several times since, so I have paid close attention, as my heart has been racing, to the conditions. It has happened when I am braking while going over manholes, speed strips, cracks in the pavement. It feels like the tire is getting hung up slightly, doesn't get any traction.the brake malfunction light comes on. Also, on the multi-information display, the indicator has just moved from eco to chg.the other day, it was 34 degrees and I was braking as I came up to a light and the car slid and vibrated. I was going about 5 miles an hour. There may have been some black ice or frost on the ground, but the shaking was intense and I had difficulty controlling the car for a few seconds until I stopped.

- Washington, DC, USA

The contact owns a 2010 Toyota Prius. The contact stated that when slowing down and making a right turn, the vehicle accelerated; however, it has never occurred when he made a left turn. He was driving approximately 10 mph. The failure mileage was 4000 and the current mileage was 5000. Updated 03/12/10. Updated 09/21/10

- Atlanta, GA, USA

There have been several times when the brakes of my 2010 Toyota Prius have released, often when I hit a bump or am going over a hill. The car feels as if it's suddenly accelerating even though I am pushing down on the brakes. This has happened at least 4 - 5 times per week since I bought my car in July 2009. Today, I was unable to stop as I approach an intersection despite pushing down on the brakes. The car hesitated and finally the brakes engaged. Luckily no one was coming through the intersection for if there had been, I surely would have hit them.

- Bath, ME, USA

Three times, twice with me and once with my wife, the automobile accelerated during braking. The acceleration (or loss of brakes, it's hard to tell) lasted for only a second, but enough where I had to press the brakes with force to come to my intended stop. I could have easily ended up in the middle of the intersection.

- Jamaica Plain, MA, USA

Today at around 220- Prius jumped or.. lurched forward as I was braking - I think on buena vista - front of St joes - I had come from partners credit union - was going to freeway 134 - I was going slow maybe 20 mph - cars were coming to stop at stoplight before freeway on ramp - as I braked gently I hit a metal cover on ground - but instead of stopping the car lurched forward - fortunately - there was ample room in front of me- I was going slow and braked early - otherwise I might have hit the stopped car in front - more than just slipping - like when braking on ice.. the car actually jerked forward - earlier in week - I was backing out of driveway at house - and as I was backing up and braking the brakes were real jerky - hard - over - responsive - then when I hit the road - going forward - brakes went back to normal.

- La Crescenta, CA, USA

While coming to a stop at a red light, I applied my brakes and at the same time, went over a small pot hole. It seemed to me like the car sped up. It only happened for a split second but that second could mean the difference between hitting someone and missing. This has happened twice to me and I do think it is a very dangerous situation. I have been told this is by design but if it is, it is a poor design.

- Garnet Valley, PA, USA

2010 Prius acceleration surge - when I drive over a sewer cover or any similar indentations in the roadway the vehicle surges forward in an aggressive manner. I need to apply the brakes or steer to avoid any object in the path of the vehicle. It is very unsettling and dangerous since the surge is strong and unpredictable.

- Chicago, IL, USA

I have a 2010 Toyota Prius, when I am trying to stop and hit a pothole, or manhole cover or the streets are wet, the car's brakes will disengage temporarily. It is scary and I've almost had a few accidents. Please look into this.

- Brooklyn, NY, USA

The contact owns a 2010 Toyota Prius. During brake application while making a left turn onto a gravel road, the vehicle surged forward. Identical failures occurred three times. The dealer was contacted and they stated that they did not have any reports of the failure. The vehicle has not been diagnosed. The failure mileage was 2800. The current mileage was 6000. Updated 01/29/10 updated 01/29/10.

- Alden, IA, USA

I have owned a 2010 Prius for about a month, and have driven just over 1000 miles on it. There have been three separate incidents now where my brakes have experienced a sudden failure while decelerating. Each time occurred right after hitting a pothole or a bump in the road. Passengers in my car have reported a feeling of the brakes "catching" or "jerking" while driving on bumpy roads. The three incidents I have mentioned were during winter and during possibly icy conditions. However, I know how to operate a vehicle on ice, and I am aware of how ABS braking feels. During each incident, I would be braking slowly, with plenty of time, then hit a bump, and experience a feeling of skidding while the brakes disengaged for a few seconds. I almost hit a pedestrian at a toll booth, a concrete divider during highway driving, and another motorist at a sudden stop condition along another highway. Please investigate these cars. I can compensate my driving skills to adjust for road conditions that I am aware of. If any sudden braking is required, and I hit a pothole at the right time, I will not be able to stop.

- Williamsville, NY, USA

I have a new Toyota Prius 2010 and have experienced the loss of braking combined with a simultaneous acceleration about 4 times now. It is incredibly scary. I have never had this happen on any other car that I've driven. It happens when I hit a bump in the rear. I now see that many people are experiencing this as I saw an article on msnbc.msn.com. I now see that others are experiencing the same problem. This has to be investigated. The last time it happened I was facing a cliff and had the car not stopped, my daughter and I would have gone off the cliff and probably would have perished. This is asking for accidents to happen and something must be done to fix this problem. There are way too many of these cars on the road. I do not have the win number on hand, but will add it tomorrow. This has occurred approx 4 times and the car accelerates at the same time I lose braking capabilities.

- Santa Monica, CA, USA

I have a 2010 Prius which I bought in August 2009. On several occasions, approximately 8-10 times, I have been braking at slower speeds when coming to an intersection. When I put my foot on the brake and the car happens to hit a bump or hole in the road and the car noticeably surges. My foot is not on the accelerator and this has nothing to do with the floor mats because my floor mat is pinned to the floor of the car. The most recent time this happened was 12/28/2009.

- Laytonsville, MD, USA

In reverse car speeds and brake stiffens and unable to slow reverse speed. Also, two times while accelerating at 25 miles per hour the car seemed to lift up then settle down. Very frightening. Updated 02/02/10 the consumer stated when the vehicle was in reverse, the brakes froze. The day after the vehicle was at the dealer, the consumer parked on a small incline, the front facing up. When she started the vehicle, she pushed the start button, put the vehicle in reverse, disengaged the emergency brake, and immediately the brakes froze and the consumer started to go backwards without control of the backing up the car. The consumer was unable to control the backwards movement so she immediately shut down the power. She then started the vehicle again, put it reverse, disengaged the emergency brake and everything was normal. Updated 03/01/10 updated 05/05/10.

- Stamford, CT, USA

Toyota Prius 2010: When the car hits a bump in the road it will accelerate so fast by itself which can be very dangerous and fatal. It can highly cause an accident if the driver cannot step on the brakes in time to stop the car acceleration. I went to my local Toyota dealer here in queens New York and to my surprise the rep said" I have never heard of that complaint" and did not pursue the matter at all. Another safety concern is that I hit a small pothole and the whole tire was damaged on my brand new 2010 Prius which I have been driving for barely two months. I am very concerned about these safety problems and do not really know where to start getting assistance. Thank you very much.

- Astoria, NY, USA

I was driving my new 2010 Prius (approx. 250 miles on odometer) when approaching a stop light earlier today with my foot gently applying pressure to the brake when suddenly the car surged forward accelerating. I am certain my foot was not on the accelerator pedal nor was anything on the floor and the floormat was appropriately positioned. The acceleration only lasted a second, ie once I applied more pressure sharply to the brake pedal the car slowed and the acceleration ceased. This is the only time this has occurred.

- Oakland, CA, USA

I bought a 2010 Prius in September 2009. In October, I drove over a pothole that was about 6 inches deep and covered the entire width of the lane. Here is what it felt like happened: When the back wheels hit the bottom or the top of the pothole, my car suddenly accelerated and I had a very difficult time stopping it. I managed to not crash into the car in front of me, but just barely. It hasn't happened since. The pothole was apparently the result of work on the road, B/C it was squared, like the pavement had be intentionally cut.

- Fort Worth, TX, USA

2010 Toyota Prius accelerates slightly when brake is compressed and car is traveling over large road bumps or manhole covers/slippery surfaces (multiple times each time I drive). I have not yet reported this to Toyota, based on the online and news-broadcast accounts of how Toyota has responded to much more serious acceleration issues. I intend to attempt returning the vehicle to the company for a full refund.

- Chicago, IL, USA

I have a 2010 Toyota Prius and it accelerates randomly. Usually when I push on the brake a little bit, but not all the way, it will jump forward and accelerate. I heard about the issues with the mat and I removed the mat months ago. Its is still unintentionally accelerating. It has happened May 6 times since I bought the car in July. I am scared to drive it and have been driving my spare car until something is done by Toyota or someone else that cares about the safety of drivers.

- Owings Mills, MD, USA