A Tesla Semi prototype was spotted in transport, presumably, after having completed several weeks of winter testing near its cold-weather testing facility outside of Delta Junction, Alaska.
Various sightings of the Tesla Semi from over the weekend suggest that the all-electric semi-truck was making its way down the western seaboard of the United States from Washington, through Oregon, and back to its Fremont, California test facility.
Video captures of a Tesla Semi being transported on the back of a semi-trailer shows the prototype’s salt-covered exterior as it makes its way back from cold-climate performance testing under snowy conditions.
Tesla Semi have done some #SosialDistancing @elonmusk hardcore testing? pic.twitter.com/keqweQ6GSh
— John D. (@Real_John_D) March 23, 2020
In January, Tesla noted in an email communication to Semi-truck reservation holders that the truck was undergoing hazard testing at its test facility in Fremont, California.
“Over the last few months, we have continued testing the trucks in real world conditions. We also spent time at a proving ground to evaluate the truck’s resilience over rougher road conditions. Using instruments mounted on the vehicle, we collected road input data to ensure the trucks can handle severely degraded roads. At our own Fremont test facility, we subjected the trucks to a number of high energy, discreet events such as curb strikes, pot holes, and other harsh inputs to confirm the truck is capable of handling common hazards.”
In the same communication, the company indicated that Tesla Semi has already completed “important engineering development checkpoints” and would be rolling out more “production-representative vehicles” vehicles in 2021.
Ahead of planned production, Tesla Semi would undergo several weeks of winter testing. The company has an extreme cold testing facility in Alaska where its vehicles, including the Tesla Model S and Model 3, undergo intense winter testing.
“In the short term, the team is gearing up for several weeks of winter testing to validate the truck’s performance in cold weather and low traction conditions. We are excited to share insights from the winter with you, as we will be able to highlight the major advantages of electric traction and motor control, which no diesel powertrain can match,” said the company in an email to a Tesla Semi reservation holder.
Actually I re-read the letter it says they will have limited volume production 2nd qtr of 2020. pic.twitter.com/A2hTYyTVdz
— chris (@chris31402370) January 9, 2020
Tesla has not confirmed where Semi-truck production will take place, only noting in its fourth-quarter earnings update letter that the facility would be in North America.
CEO Elon Musk indicated in the Q4 earnings call that Tesla Semi would be initially produced in limited quantity as the company focused efforts on increasing battery production capacity. Given the size of the all-electric truck and its energy needs, having a strong supply of battery cells is crucial to preventing a strain on supply for its consumer vehicles like the Model 3 and Model Y.
“So, the thing we’re going to be really focused on is increasing battery production capacity because that’s very fundamental because if you don’t improve battery production capacity, then you end up just shifting unit volume from one product to another and you haven’t actually produced more electric vehicles,” said Musk when asked about the Tesla Semi. “So, that’s part of the reason why we have not, for example, really accelerated production of the Tesla Semi because it does use a lot of cells and unless we’ve got a lot of battery cells available, then — and say like accelerating production of the Tesla Semi would then necessarily mean making pure Model 3 or Model Y cars. And so, we’ve got a really — make sure we get a very steep ramp in battery production and continue to improve the cost per kilowatt-hour of the batteries.”
A Tesla Semi was captured on Sunday, making its way down Interstate 5 in Olympia Washington, roughly 60 miles south of Seattle. Credit: Tvlog.
Tesla has reached a notable benchmark in its autonomous driving program after its Robotaxi fleet surpassed one million miles of unsupervised operation. The company made the announcement during its Cybercab event in Austin on September 3.
Tesla Vice President of AI Ashok Elluswamy told attendees he was happy to report the fleet had achieved one million miles of unsupervised Robotaxi operation as a testament to safety.
The new total marked a sharp increase from the 380,000 unsupervised miles Tesla disclosed during its second-quarter 2026 earnings update in late July.
In roughly six weeks, the company added about 620,000 miles. That acceleration followed Tesla’s decision to remove in-vehicle safety monitors from most of its operations outside the San Francisco Bay Area.
Credit: Tesla
Tesla first launched Robotaxi service in Austin in June 2025 with safety drivers present. It later began fully unsupervised rides and expanded into Dallas, Houston, Miami, Orlando, and Tampa. The San Francisco Bay Area remains the exception, where a safety monitor still rides in the vehicle under California permitting rules.
The company has not released a city-by-city breakdown of the one million unsupervised miles.
The milestone arrived as Tesla began offering public Cybercab rides in Austin. The purpose-built vehicle has no steering wheel or pedals and is designed only for autonomous ride-hailing. Production versions joined the existing fleet of modified Tesla vehicles already operating in the service.
Tesla’s unsupervised mileage is growing at a double-digit weekly rate according to earlier company comments, yet its fleet size remains modest compared with established competitors. Waymo has accumulated more than 200 million fully autonomous rider-only miles. Tesla has described its own unsupervised operations as having recorded zero notable incidents in the period leading up to the July update.
The one-million-mile figure reflects Tesla’s shift from supervised testing to broader driverless service in multiple states. It also highlights the company’s strategy of using both existing Model Y vehicles and the new Cybercab to scale its network.
Credit: Tesla
Whether the rapid recent growth continues will depend on further city expansions, regulatory approvals, and the performance of the purpose-built Cybercab in everyday paid rides. Tesla has not specified how many of the latest miles involved the new vehicle versus the rest of the fleet.
The announcement underscores Tesla’s progress toward a larger robotaxi network while illustrating the remaining gap in total autonomous experience relative to longer-operating rivals.
Tesla AI lead Ashok Elluswamy said this week that 24-hour Robotaxi service is close. Replying on X to a rider who wanted Cybercab trips all night, he wrote that the capability would arrive “next month or so” once “the next tech to merge on the v15 plan” is ready.
The comment landed on September 4, one day after Tesla opened public Cybercab rides in Austin. It is the clearest near-term timeline yet for overnight unsupervised operation. Tesla’s paid Robotaxi network currently runs from 6 a.m. to 10 p.m. seven days a week across Austin, Dallas, Houston, Miami, Orlando, and Tampa.
next month or so. the next tech to merge on the v15 plan will enable it.
— Ashok Elluswamy (@aelluswamy) September 4, 2026
That 16-hour window is shorter than the 6 a.m. to 2 a.m. schedule the company used for much of the prior year.
Elluswamy did not name the specific feature or say whether the change would apply first to purpose-built Cybercabs, the existing Model Y fleet, or both. He also offered no city-by-city rollout list. The link to Full Self-Driving v15 is nevertheless significant.
Tesla has described v15 as a step-change architecture with seven parallel improvement tracks and roughly ten times more parameters than earlier builds. Early versions of that software already operate on the Robotaxi fleet and contain about 40 percent of the planned gains.
By July 2026, the unsupervised fleet had logged more than 380,000 miles across six cities in two states with what the company called an impeccable safety record and no notable incidents caused by the vehicles themselves. Tesla has repeatedly argued that camera-based end-to-end neural networks, rather than extra sensors, are the core of the solution.
Overnight service would test that claim in lower-light conditions and would also raise vehicle utilization, a key variable for Robotaxi unit economics. The company has already begun using public Superchargers at night and is building dedicated Robotaxi charging sites.
Riders have asked why software must change if the cars already drive in the dark. The practical answer appears to be reliability and scale: Tesla has held back mass expansion until more of the v15 stack is merged, citing the need for higher confidence before putting thousands of unoccupied vehicles on streets around the clock.
If the next module arrives on the timetable Elluswamy sketched, 24-hour service could begin in October 2026 in at least some markets.
That would mark a shift from a daytime-bounded pilot to a service that can run whenever demand exists, including the late-night hours that have so far remained out of reach.
Tesla is beginning to roll out Full Self-Driving Supervised v14.3.9 with a new active safety layer that can take control even when the driver is operating the car manually.
Tesla AI said the software can activate FSD on the driver’s behalf when an imminent collision is detected and Automatic Emergency Braking may not be enough. It may also engage if the system detects heavy distraction or an accidental FSD disengagement.
FSD Supervised v14.3.9 starting to roll out shortly
This release includes a new active safety feature set: FSD Supervised can now activate on your behalf when an imminent collision is detected and Automatic Emergency Braking (AEB) may not be enough.
It may also engage if we…
— Tesla AI (@Tesla_AI) September 4, 2026
The capability is essentially Automatic Collision Evasion. However, unlike conventional AEB, which mainly applies the brakes in a straight line, this feature can use steering, braking, and acceleration together if the car calculates that stopping alone will not prevent impact and a safer path exists. The system may change lanes or move toward a shoulder when conditions allow, then continue driving after the immediate threat is handled rather than simply coming to a stop.
The intervention is meant as a last-resort safety net, not a replacement for attentive driving.
Tesla Full Self-Driving v14.3.7 early review: FSD saved me from an accident
Tesla’s own description still frames FSD as supervised assistance. Secondary reports on internal release notes say the feature can fire while the car is being driven manually if cabin-camera monitoring suggests the driver is not sufficiently attentive, such as reaching toward the back seat, or if FSD appears to have been turned off unintentionally.
After the emergency maneuver, the car is expected to alert the driver and request a return to manual control.
The safety case is straightforward. Many collisions happen in the last second because a driver is looking away, fumbles a control, or faces an obstacle that braking cannot fully solve. A system that can both recognize that AEB is insufficient and execute a coordinated evasive path can reduce those remaining high-severity events.
Re-engaging after accidental disengagement also addresses a practical failure mode: a small steering nudge that drops FSD at the worst moment. The advantage is a background safety net that uses the same vision stack already running in v14, instead of leaving the car solely to emergency braking once the driver is no longer in command.
The feature still depends on FSD being enabled and, according to reports, an active FSD purchase or subscription. It does not make the vehicle unsupervised. Drivers remain responsible, and Tesla has not published how often the system is expected to intervene or how it will handle false positives.
If the rollout is conservative and the false-alarm rate stays low, the update is a meaningful step: FSD is no longer only a feature the driver turns on. In the rare moments when disaster is already forming, it can step in.
Tesla crosses major Unsupervised Self-Driving milestone
Tesla Robotaxi will be a 24/7 service: here’s when
