Adaptive Cruise Control problems of the 2026 Tesla Model Y - part 1

While driving on colorado state highways with traffic-aware cruise control (and/or autopilot) engaged, the vehicle repeatedly and unexpectedly decelerates rapidly from highway speeds of 75–80 mph down to approximately 45 mph. This occurs with no vehicles, obstacles, or other hazards visible ahead that would justify the slowdown. The deceleration is abrupt and feels aggressive. It has happened on multiple occasions during normal highway driving. I am forced to immediately override the system by pressing the accelerator to regain speed and avoid creating a hazard for traffic behind me. The issue occurs even in clear conditions with good visibility. This sudden braking creates a significant safety risk of being rear-ended by other drivers who are not expecting a vehicle to drop 30+ mph without warning. I have experienced this repeatedly and am concerned it is a safety defect with the vehicle’s cruise control / driver-assistance system. The problem occurs specifically when cruise control is active and does not appear to happen in the same way when I am fully controlling the throttle manually.

This car was operating under "full self driving (supervised)", on [xxx] at [xxx], traveling on [xxx] near thornton gap. With no operator inputs, the car fully changed lanes to the left, crossing over the double-yellow line into the oncoming traffic lane. All four tires of the car crossed into the westbound lane before the car, still operating under full self driving (supervised) changed back into the eastbound lane. The operator of the car was prepared to take control, however without oncoming traffic at the time the car was allowed to complete the maneuvers. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The speed limit displayed to the driver is frequently incorrect. I believe this is a problem with all Teslas. Speaking as an aerospace engineer- as a rule it is better to provide no information to the pilot/driver than wrong information. Faa would never tolerate faulty instrumentation in an airplane, and we shouldn’t tolerate it in cars either. When the car is operating in fsd , it uses this wrong speed limit information. And operators driving manually will often rely on the displayed speed limit. Not good.

The speed recognition of Tesla full self drive is unsafe in its present form. The speed recognition is very inaccurate. While driving on an interstate highway where the speed limit is 70mph, it is recognizing a route sign with a much lower number as a speed limit sign and suddenly applying braking, causing me to nearly be rear ended on multiple occasions. Every time I pass this sign I have to either disengage full self drive, or I have to override it to keep from being rear ended. The same thing happens on another highway, where the exit ramp has construction going on. When you are on the main road, it recognizes the exit ramp construction speed limit and tries to reduce you from 65 to 35. This problem has been reported to the manufacturer with no response other than "it is being forwarded on to the appropriate team for review".

Tesla supervised full self driving sped southbound into a school speed zone. Flashing speed zone yellow lights required speed of 20 mph. Tesla continued at 49-50 mph. Driver intervention was required to slow down to 20 mph. There has been one other incident reported for this Tesla in the same school zone operating northbound last week.

Full self driving (fsd) has taken away my ability to set a maximum speed. Car is frequently wrong about the speed limit, especially in constructions zones where the speed limit changes more often. Car goes way too fast, then thinks the speed limit dropped and slows way down and then speeds up again. In addition, the 4 speed profiles they gave us instead of a simple max speed setting are useless. Standard mode usually works best but will sometimes do more than 15 mph over what it thinks the speed limit is.

I was using fsd today and was driving along highway 24 in orinda and the car almost hit the highway island at speed of 64 mph. I attached the bideo.

This is an issue with Tesla's full self driving (supervised). The categories above don't match this capability. Sunday, xxx, about 6:05 pm. Fsd (supervised) version 14. 3. 9. Leaving in-n-out burger, [xxx], fsd chose to exit westbound onto [xxx]. A vehicle coming from the east had gone around the queue on my right and was westbound on [xxx]. Fsd pulled forward so the nose entered that westbound lane in front of that car. I intervened with throttle and steering. No contact. Since I didn't honk there was no saved dashcam clip. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Whenever I disengage full self driving the car forces me to tell it why I did it via an on screen selection. It does not go away after a period of time. I used to be able to dismiss it by hitting the voice button twice but they've removed that loop hole. It's very distracting and forces me to interact with the screen while driving. The selection screen also blocks the blind spot cameras. It comes up even when disengaging to park. Someone is going to wreck messing around with this forced distraction.

I recently purchased this vehicle. I love it. It has a trial of full self driving, which I love almost all of the time. However, I noticed there is not any of the 5 settings for fsd that do not speed in school zones. I want to use fsd as much as possible, but I will not speed in a school zone. I am amazed that Tesla has been allowed to program the fsd in a way that will allow speeding in a school zone. I have to turn off fsd to maintain safety and avoid a ticket. Please require Tesla to have at least one of the 5 settings that will obey school zone speed limits.

Fsd routing issue: it’s a repeatable fsd lane selection safety issue, france avenue south to I-494. Description: when using fsd from france avenue south onto I-494, the system turns into the westbound only lane instead of staying in eastbound lane. At the end of westbound lane, fsd performs a sudden, last-second swerve into the eastbound only lane, cutting off vehicles behind already existing n the eastbound lane. This has happened multiple times, including both before and after the latest update v14. 3. 8. Expected behavior: fsd should identify the correct east only lane well in advance and stay in it when the rout is set for east 494. Concern: the late lane change cuts off traffic and creates a collision risk.

My 2026 Tesla Model Y has repeatedly developed contamination/haze inside the enclosed forward-facing windshield camera area, resulting in camera visibility/cleaning warnings and potentially reduced availability or performance of driver-assistance features. Tesla has already cleaned the internal forward-camera/windshield area twice, but the condition continues to return. The contamination is located inside the camera enclosure/inboard windshield area and cannot be corrected through normal exterior vehicle cleaning. Tesla is now requesting approximately $60 to clean the area again rather than addressing why the contamination repeatedly develops. I am concerned that this is a recurring defect affecting forward-camera visibility rather than ordinary owner maintenance. The forward cameras are used by the vehicle’s driver-assistance systems. I am also aware of reports from other owners of newer Model Y vehicles experiencing recurring haze/contamination in this same enclosed camera area. I am requesting that NHTSA document and evaluate this issue for a possible defect trend in 2025+ Tesla Model Y vehicles.

On xxx at about 6:14 am, my 2026 Tesla Model Y drove into a flooded railroad underpass on [xxx] near [xxx], with full self-driving (supervised) engaged and a navigation route active. It was raining heavily (newark airport measured 1. 25 in from 5:51 to 6:51 am), the light was poor around sunrise, and the underpass was dark. The water depth was not apparent to me. At 6:12 am the national weather service had issued a flash flood warning naming [xxx] and listing underpasses. Tesla's data log (my privacy export) records fsd active from 6:12:02, my third fsd session that morning. With fsd active, speed rose from 7 to 27. 4 mph between 6:14:04 and 6:14:31, with no accelerator input recorded. Speed then fell sharply (up to about 0. 3 g), which I believe is when the car hit the water. Fsd stayed active about 8 seconds (200 ft) more; the state changed to aborting at 6:14:39, at about 6 mph. I saw no warning, and the export shows none during the approach. We could not drive out. Water rose to about window level and entered the cabin. From 6:17 the log shows restraint system, aeb, abs, stability and traction control alerts. I lowered a window at about 6:19. At 6:25 the log shows both front door releases activated repeatedly; neither door opened. We climbed out the window onto the roof. Our videos show us there at 6:31 with the front of the hood and headlights under water, and the elizabeth fire department rescued us by boat at about 6:51. The car is a total loss. Unknown: exact water-entry speed, what fsd perceived, and why it disengaged. I ask NHTSA to investigate whether fsd detects and responds to flooded roads in heavy rain and poor light, to obtain Tesla's data for this event, and to review escape from a flooded vehicle whose doors did not open. A report with the data timeline is attached. The full Tesla data export and videos are available on request. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Phantom braking while using the tacc on the Tesla.

While using fsd feature continuously for more than 45 minutes without stopping the system locks on to the previous road speed limit and freezes and the car ignores any new different speed limits and runs into fully rouge mode. . . And almost ran into a pedestrian without slowing down. Example - if road speed limit is 45 mph and car driving between 45-50 mph and when the road speed limit drops to 35 or 25 mph car continues to run at 45-50 mph. Ex2: if car running at 35 mph and later enters highway the car continues at 35 mph on highway where speed is 65 mph and likely to cause accident. The Tesla does not have any forum or email support or phone support to address this issue and says it will reset if I stop on highway and wait for 15 mins to reset and then start again. This occurs every time if you drive continuously without stopping ( turning off car) for 45 min or more.

On [xxx], at approximately [xxx], my 2026 Tesla Model Y (VIN: [xxx], delivered [xxx]) was involved in a rear-end collision while the full self-driving (fsd) system was actively engaged. The dashcam footage clearly shows "self driving" displayed in blue on the instrument panel at the time of the incident, with the vehicle traveling at 3 km/h in drive (d) mode. What failed: the fsd/adas system failed to detect the stopped vehicle ahead and did not apply braking or issue any collision warning prior to impact. Safety risk: the system had full control of the vehicle at the time of the collision. I was not manually operating the vehicle. The failure of the fsd system to respond appropriately caused a rear-end collision. Dealer/service confirmation: not yet confirmed by dealer. Incident occurred 2 days after vehicle delivery. Inspections: under review by insurance. Police report pending. Dashcam video evidence preserved. Prior warnings: no warning lamps or alerts were displayed prior to the collision. The fsd system gave no indication of the impending failure. Dashcam footage showing active "self driving" status at time of crash is available upon request. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

When using Tesla fsd, the car insists on following the car in front at an unsafe following distance…. Frequently less than 1 second behind it.

Tesla full self driving, installed version 14. 3. 6 is still unable to reliably obey speed limits. The driver of the car has no method of controlling full self driving to slow down the car to meeting the new speed limit. The full self driving (fsd) safety system must be disabled to regain speed control. Tesla claim in multiple social media posts that fsd is "significantly" safer than humans, but it will not reliably maintain accurate speed and instead will often attempt to significantly exceed the posted speed limits. Xxx driving through [xxx] on highway xxx heading west, with fsd controlling the car. The posted speed limit is 45, suddenly the car changed speed to 55, then faster. The only recourse is to disengage the fsd safety system to regain sensible speed. I have included one location, but this is a very widespread issue that covers much of [xxx], [xxx], [xxx] and [xxx]. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

On many occasions in the year we have owned our Tesla Model Y, we have experienced sudden, unexplained braking while using the traffic aware cruise control (tacc) feature. We have experienced several near-misses of cars or semi tractor trailers rear-ending us. These incidents were avoided by quick reaction of the Tesla driver to override the tacc. I have documented several incidents using the dash camera on the car and have assembled a spreadsheet of times and places of occurrence that correspond to the videos. One Tesla service representative dismissed my complaint by saying the feature is working as designed, so nothing further was done. A representative at a different dealership acknowledged that it is a known characteristic in the current firmware and they expect it to be addressed in a future software update. As I said, we have been experiencing this for over a year. It is a clear safety hazard, not only for the Tesla driver and passengers, but also for any vehicle following who has to react to the sudden, unexpected braking.

Tesla full self driving has no way to limit the speed or lane changes, and even in its standard profile it keeps going 15+ over the limit. Chill mode occasionally goes 10+, and sloth switches between -10 and +5 erratically. It's unsafe to use and there's no way to do anything about it without a manual speed limit, like it used to have.

Supervised self driving. The latest software requires drivers to divert attention from the road to enter information on the screen whenever self driving is disengaged. This is potentially dangerous.

The contact owns a 2026 Tesla Model Y. The contact stated that while driving approximately 55 mph with the cruise control engaged the vehicle lost automotive power. No warning lights were illuminated. The failure had occurred on several occasions. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure and had received similar complaints; however, there was no fix available for the failure. The failure mileage was approximately 100.

We have owned a 2026 Model Y Tesla for one week and have encountered these dangerous behaviors while in full self drive mode, even in “sloth” mode: 1. Tailgating, repeatedly, while at highway speeds. Controls did not allow me to increase trailing distance while in fsd. 2. Dangerous merging, cutting off other cars. 3. Failure to read surface directions and driving wrong way against oncoming traffic. And this is with only one week of casual driving!.

On the highway, a vehicle in the lane next to me on the right moved towards the white dividing line, but never actually crossed into my lane. My Tesla was operating on full self-driving (supervised). The system miscalculated the front vehicle's trajectory and severely overreacted to it approaching the line. Without driver input, the fsd system initiated sudden, heavy braking and violently swerved to the left, crossing the lane line. Because the Tesla swerved suddenly into the left lane, the driver already occupying that lane was unable to avoid a collision, striking the left rear corner of my vehicle. I have video recordings from my Tesla that provides objective proof that the vehicle in front did not sideswipe or cut off my car, but rather that an abrupt vehicle automation failure forced my car out of its lane, I had no chance to react quick enough to avoid the accident. It also provides context as to why the driver behind me could not avoid the impact. I have preserved the video files and am ready to submit them to you immediately. Best regards [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Using Tesla fsd 14. 3. 3. It began raining hard, causing standing water to pool on the road. The standing water was making the car lose traction and started sliding within the lane, it did change its speed or driving to account for the rain. Fsd was doing over the speed limit and would not slow down slower than the speed limit. Changing the Tesla speed profile from standard to sloth slowed it down to exactly the speed limit but no lower. At this point the car could not maintain its lane, I feared for our safety, so I had to disengage fsd to regain control of the car. Tesla have removed all methods of allowing the driver to maintain accurate speed control of the car and it often ignores speed limit signs, which means it is traveling too slow or too fast for the currently posted speed limit.

Tesla recently pushed a software update that introduces a major, unavoidable driver distraction right at the most critical moment of driving: the exact second you take manual control back from full self-driving (fsd).   whenever you disengage fsd, a mandatory, multiple-choice survey pops up on the center touchscreen asking why you took over. Unlike previous versions where this would disappear after a few seconds, it now stays on the screen permanently. There is no close button, and it does not time out.   this causes two clear safety hazards while driving: 1 it blocks the screen: the popup actively covers up part of the navigation map and basic screen controls. If you are trying to navigate a tricky intersection or see your route right after taking over, you can't see the map clearly because this giant survey is blocking it. 2 it forces you to look away from the road: because the prompt never goes away on its own, it forces the driver to physically look down, read the small text options, and tap the screen to clear it. Forcing a driver to do a multiple-choice survey while actively managing a manual takeover in traffic is incredibly dangerous. Tesla should not be allowed to use a mandatory, permanent ui popup to collect data while a vehicle is actively moving. It is a severe visual and cognitive distraction at the exact moment a driver needs to be 100% focused on the road. Please investigate this software design and require Tesla to add an automatic timeout or a quick-dismiss button that doesn't require driver interaction.

Adaptive cruise control slams on the brakes at highway speed alleging “curvature assist” on flat, straight roads. Dealer replaced firmware and problem persists. Defect appears to be inherent to adaptive cruise control.

At about 2:16 pm on Monday, 5/18/2026, I was driving southeast in the right lane of amaya drive from fletcher parkway in la mesa, CA, planning to turn right across the trolly tracks onto severin drive. There is an intermittent led sign indicating no right turn in the southeast corner of the intersection, just below and to the right of the ground-level stoplight, that illuminates when the trolley is passing so traffic going straight on amaya can still proceed. In the first street view pdf I uploaded, it is not illuminated. I had fsd engaged, and as I approached the intersection the no right turn led was illuminated. If I recall correctly, I assumed fsd would stop for the no right turn led; but instead, it continued to make the right turn. Luckily my son was in the right seat and yelled several times for me to stop, which I did—just a few feet from the crossing arm, which can been seen elevated in the middle of the second street view pdf I uploaded, and which was just coming down for the approaching trolley. By the time I got stopped, the crossing arm was fully down, and as noted above I ended up just a few feet from it, and would clearly and unequivocally have driven under and through it if I hadn’t braked suddenly. It’s clear that this was completely the fault of fsd either not reading or not being aware of the intermittent no right turn led sign. Since fsd clearly doesn’t read no right turn signs, particularly intermittent led signs, the solution seems to make this intersection no right turn whenever the light is green to pass through the intersection on amaya, although this will hold up the cars who would like to turn right when there’s no trolley approaching.

The latest Tesla autopilot software forces users to engage in an autopilot product survey after disengaging autopilot while driving in order to gain access to audio/radio controls. The survey is not dismissible without reading a complicated prompt and choosing a response, and it completely obstructs audio controls until you participate in the survey. The driver therefore cannot turn off music to listen for emergency sirens, pedestrians, or other potential safety cues while driving at any speed, unless the driver also takes eyes off the road to participate in the forced product survey. This is by design and affects all Tesla drivers who use the autopilot feature.

I have been a user of Tesla's "full self driving" technology for four years. In one of the last major updates, the company removed the ability of the driver to manually set a "cruise control set point" to maintain a safe speed. Instead, they employed a new system with five "drive profiles," which included "sloth," "chill," "standard," "hurry," and "mad max. " the problem is that only two of those stay anywhere near the speed limit. "sloth" will go the speed limit, "chill" is about 2 mph over the speed limit, "standard" is about 7 mph over the speed limit, "hurry" is 12 mph over the speed limit, and "mad max" is probably 15-17 mph over. Sloth and chill will remain in the right lane, rarely passing another vehicle, but all the others will include lane changes. And all of these profiles do not maintain a safe following distance. Users have been complaining about the cars tailgating, sometimes as close as 3 car lengths at 70 mph. However, sometimes conditions necessitate slower speeds. . . Like work zones. I live near denver, and I-70 has a work zone that will be in existence until 2029. The car doesn't recognize the 45 mph speed limit, bouncing back and forth between 45 and 65. Fsd must be disengaged completely to follow the 45 mph speed limit. Which brings up the other problem. In many areas, the speed limits are wrong. In texas, there are areas where the speed limit is 70, and the car thinks it's 55. In new mexico, the speed limit is 70, but the car thinks it's 60. There is no speed profile that will maintain the legal limit. Tesla also has a mechanism that's supposed to allow users to report problems, but some of these I've been reporting for over three years. They refuse to tell us where we can update the information (grok says "here," tom tom, open street maps), and they are not fixing the speeds on the maps.

The standard cruise control is extremely dangerous. The problem is what I hear is called ghosting. When driving using cruise, and there are no other vehicles nor any other objects such as animals or humans. The car will suddenly decelerate almost to the point of a complete if not overridden by manual takeover. I am under the impression that this is intentionally be done by Tesla, so that you will subscribe to their full self driving service. This can and will cause accidents in traffic.

Running full service driving (fsd) v14. 2. 2. 5 on hw4. At skillman st & I-635 dallas TX, fsd attempted a wrong way turn into oncoming traffic instead of taking the correct leftmost lane. In the image attached instead of following the blue path Tesla took the wrong lane highlighted in red.

Driving using autosteer feature at 65mph on expressway, attempted to change lanes which caused the cruise control to suddenly turn off causing the car to begin braking hard with traffic behind it. Tesla’s new Model Y has combined the lane keeping and cruise control so if the lane keeping turns off the car suddenly brakes hard from the regenitive brakes. Lane keeping and cruise control should be two separate controls to prevent this issue.

Subject: Tesla self-driving / autopilot incorrect maneuver at intersection vehicle: Tesla (model: **)?software: full self-driving / autopilot (specify which was active)?date: __[xxx]__?time: _[xxx]___?location: _** carlos, [xxx] ____ (city, intersection or street) description of incident: while the vehicle was operating with Tesla’s driver-assistance system engaged, the navigation indicated the car would turn right at an intersection. As the vehicle approached the intersection and began the maneuver, it unexpectedly continued straight instead of completing the right turn. This caused the vehicle to enter the intersection in front of other vehicles that were stopped at another traffic light. I had to intervene to ensure safety. There was no clear reason for the incorrect maneuver, and the system behavior was unexpected and potentially dangerous. Additional information: •weather conditions: ___good weather _clear__ •traffic conditions: ___lot of traffic people getting off work___ •driver intervention: yes / no (explain briefly)yes heading straight to cars if I had not made a quick maneuver and turn the steering wheel. I would have crash hitting at least one or two cars. •dashcam footage available: yes / no no I am submitting this report so the event can be reviewed for possible software or safety issues with the driver-assistance system. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

I am writing to formally report a serious safety failure involving Tesla’s full self-driving (supervised) feature, which resulted in property damage and a severe safety hazard. While fsd (supervised) was fully engaged, the vehicle failed to detect a large block of wood in the roadway. The vehicle struck the object, causing significant damage to the brand-new car's left-side tire and body, t touched two other cars hence I called 911 and reported it to ensure they remove the wood. Because I did not know how to manually trigger the dashcam save at the exact moment of the crash, video footage was not captured locally. However, the vehicle’s internal sensors, and event data recorder (edr) should have logged the active fsd status and sensor data at the time of impact and potentially save it. Immediately following the incident, I contacted emergency services via 911 to report the roadway hazard. I have since visited a Tesla service center, where staff informed me that I must wait for the formal complaint process to proceed. Due to recent publicly reported fatalities involving fsd, I strongly believe this software is not safe for public roads, and I have chosen not to renew the feature. I am requesting a comprehensive corporate review of my case. I expect Tesla to pull the vehicle's internal logs, take accountability for this hardware and software failure, provide a full repair of the vehicle, costs about $2000 as estimated by their collision center and issue a complete reimbursement for the damages.