Skip to main content

Tesla self-driving traffic light and stop-sign interaction explained in leaked manual

Tesla is about to release a new update that will result in its Autopilot, under its Full Self-Driving package, reacting to traffic light and stop signs.

We get the full explanation of how the new feature works, thanks to the leaked manual.

As we reported last week, Tesla has started to push an Autopilot update with the actual ability to handle intersections to its “early access fleet,” a group of owners who beta test new software update from Tesla.

We even got to see a quick demo video.

Now thanks to Tesla hacker Green, we get to see the whole manual for the feature — going into details about how it works.

Tesla writes:

When Autosteer or Traffic-Aware Cruise Control is active, Stopping at Traffic Lights and Stop Signs is designed to identify stop signs and traffic lights and slow Model 3/Model Y down to a stop. This feature uses the vehicle’s forward-facing cameras, in addition to GPS data,, to detect upcoming traffic lights, stop signs, and road markings.

So the feature is called “Stopping at Traffic Lights and Stop Signs” and works on top of Autopilot’s Autosteer and TACC.

Also, this confirms that the new feature at least partially relies on GPS data, which we know is not always accurate.

As expected, Tesla makes it clear that the feature is in beta and that the driver is always responsible:

Always pay attention to the roadway and be ready to take immediate action. It is the driver’s responsibility to determine whether to stop or proceed through an intersection. Never depend on Stopping at Traffic Lights and Stop Signs to determine when it is safe and/or appropriate to stop or continue through an intersection.

This message is extremely important and should be at the top of everyone’s mind when using the feature.

Especially when you consider the list of limitations that Tesla provided for the new feature:

  • Railroad crossings
  • Keep-out zones
  • Toll booths
  • Crosswalk systems
  • Yield signs or temporary traffic lights and stop signs (such as at construction areas)
  • Miscellaneous traffic U-turn lights, bicycle and pedestrian crossing lights, lane availability lights, etc.

Some of these are actually quite common at intersections.

Furthermore, while the feature aims to stop at a red light, they require input from the driver to go through green lights.

Tesla explains that the vehicle will require permission from the driver to cross traffic lights even if they are green:

When Stopping at Traffic Lights and Stop Signs is enabled and you are using Autosteer or Traffic-Aware Cruise Control, the touchscreen displays a popup message to inform you that an upcoming traffic light, stop sign, or road marking has been detected. As it approaches the stop location, even at an intersection in which the traffic light is green, Model 3/Model Y slows down and displays a red line to indicate where the vehicle will come to a complete stop. To continue through the intersection (again, even if the traffic light is already green), you must press down on the gear lever or briefly press the accelerator pedal to give the vehicle permission to proceed. When you’ve confirmed that you want to proceed, the red stop line turn gray and Model 3/Model Y continues through the intersection and resumes your set cruising speed.

For more information, check out the full release notes, which include a bunch of intersection scenarios and how Autopilot would handle them:

FTC: We use income earning auto affiliate links. More.

Stay up to date with the latest content by subscribing to Electrek on Google News. You’re reading Electrek— experts who break news about Tesla, electric vehicles, and green energy, day after day. Be sure to check out our homepage for all the latest news, and follow Electrek on Twitter, Facebook, and LinkedIn to stay in the loop. Don’t know where to start? Check out our YouTube channel for the latest reviews.



Avatar for Fred Lambert Fred Lambert

Fred is the Editor in Chief and Main Writer at Electrek.

You can send tips on Twitter (DMs open) or via email:

Through, you can check out Fred’s portfolio and get monthly green stock investment ideas.