Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Speed limit detection problems

Hi all,

I've driven about 2500km now, most of it with autopilot engaged and encountered several issues chiefly to do with speed limit detection. It appears that my brand new 2020 Model S Performance simply does not read speed limits from camera input. I've driven through a dozen roadworks zones where the limit was clearly signposted as 80km/h (down from 110 or 100km/h) and not in a single instance did it recognise it. All of those roadworks signs were analog signs, i.e. no LED signs which might not be legible by the camera because of frame rate chopping.

While using navigate on autopilot I've encountered some far worse issues: The car suddenly thinks the limit is 40km/h (in a 100km/h) zone - it shows 40km/h limit on the dash - and breaks abruptly. Rear-ending almost ensued on that one! While in the Lane Cove tunnel in Sydney (80km/h limit) it suddenly slowed to 60km/h showing the corresponding limit. It seemed to think I was not in the tunnel but on streets above. The problem corrected itself after exiting from the tunnel. On the map however it did show me correctly as being on the M2 heading towards Sydney.

This kind of stuff is worthy of reporting to Tesla, however, they don't seem to have a technical fault report email address where I could provide them with exact date/time stamps and video footage. Does anybody know how to get in touch with them?

On the upside, the autosteer has worked flawlessly so far. The only places it gets confused are places where I get confused also. The markings for the time of day dependent lane switches in the Sydney Harbour Bridge area are nothing short of criminally negligent - I've never understood how they get away with that.
 
As others have said, there is no speed sign/limit detection in current autopilot hardware and software. It currently works off a limited database of what the road speed limits are, and limiting it to the expected speed limit is also not complete, but further limited to only high traffic areas, and only with autosteer enabled (where it will say something like autosteer limited to 60km/h in a 60 zone.)
 
Thanks all for your replies. If that is true, and speed detection is purely from a database, then we're a loooong way away from FSD! Speed limit detection based on posted road signs is not only a trivial AI problem compared to obstacle detection and avoidance, it's implemented in most competitors vehicles who only implement an embarrassing subset of intelligent features otherwise! e.g. Toyota/Lexus/Subaru who will adapt cruise control speed from said AI system but won't auto start from a full stop in bumper to bumper traffic (which infuriated me to the point of wanting to burn the car), or Mercedes/Audi who do the same, but on top of that tell you when you're too tired to drive, so they are wasting time developing driver monitoring solutions instead of putting those resources into taking that arduous task off our hands. Or my absolute favourite: cars who disable a seemingly random subset of adjustments and features based on whether the wheels are turning or not - yet are intelligent enough to know whether someone is sitting in the passenger seat or not for seatbelt warnings. I like Tesla's "are you a passenger" question.
 
Last edited:
  • Like
Reactions: baillies
@petergarret38 the number of satellites is the same as everywhere else on the planet, GPS satellites are in a medium earth orbit a few thousand km above ground, and they remain visible for a few hours each. Coverage varies to the same degree everywhere. We don't have any atmospheric water vapour corrections in Australia however, something that is available in the continental US. This system is called WAAS (wide area augmentation system) and keeps track of water vapour induced path delays on the GPS signals, and feeds that information back to the satellites who in turn will then let your receiver know what those delays are, allowing it to correct for the signal delays. It improves accuracy by a fair bit to usually < 1.0m position error. Wide Area Augmentation System - Wikipedia explains how that works. It was implemented so GPS can be used more reliably for instrument approaches in aircraft. But now of course finds many uses on the ground.
 
On my daily drive to work through a small country town they have fitted new speed limit signs and road marking, the red circle and limit
is on a much larger green sign, on the road they have 2 lines about 1m apart with cross lines for about 20m each side of the sign.
I wonder if this is to make speed signs recognizable by FSD etc.
Anyone else seen this new signage?
 
My problem is mine doesn't even see the speed limit signs. From reading through the above it would appear that the road I drive is so new (1-2 years) that the speed limits haven't been updated in the Grand Database yet...? Very annoying as the speed limit is 65 but the car thinks it's 45. It even starts as 65 then reduces to 45 which was the older speed limit before the bypass was built. *sigh*
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top