I live in rural Washington State, have a 2023 Y LR and subscribe to FSB Beta 11.3.6. In our rural area, the speed limit is 50mph unless otherwise posted. Tesla defaults to 25mph. You cruise along, and there is a 35mph sign, and Tesla slows you. After the end of that, there is a 'End of 35mph' sign, but no 'Speed Limit 50mph' sign. So FSD does not go back to 50mph. Currently, it also appears to ignore yellow cautionary signs at sharp curves advising lower than posted speeds. You can approach a 90° turn marked 15mph, and Tesla will not slow! This is a serious shortcoming. Google Maps seems to know the correct speed limits, but not Tesla.
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FSD Beta 11.3.6 does not understand rural road speed limits
- Thread starter melmalinowski
- Start date
I can't think of a reason why a county would post a sign that states the end of a speed limit zone instead of just posting the new speed limit. Why require drivers to recall the default speed limit? This must cause problems for non-residents.
I see those signs all the time that say 35 mph School zone then a half a mile down the road a sign that says end School Zone on roads that are 45 to 55 mph on either side of the School Zones. The you have these School Zone signs.
RTPEV
Active Member
I know that New York and Vermont work this way (or variations of it), and I'm sure other states have variations of it. I got my original driver's license in New York, and we were taught that the State Speed Limit was 55mph unless otherwise posted (in Vermont it's 50mph). So if you don't see a speed limit sign instructing otherwise, you can assume the speed limit is 55mph. And like Washington, when you come out of a reduced speed zone, you see a sign that says "END 30 SPEED ZONE". I suppose this gives them the flexibility to change the state speed limit to something else (not that they've ever done that during my lifetime). And it also has the advantage that they don't have to post speed limit signs at intervals along country roads.
Most 55mph zones are indicated with signs that say "STATE SPEED LIMIT 55" (not just SPEED LIMIT 55) so you are reminded quite frequently what the default speed limit is. Maybe it's because I grew up there, but I don't think it's that confusing to know that when you come out of a town with a lower speed limit that the limit reverts to 55. But yeah, it is strange that they don't just post the new speed limit on the sign. I guess it's a throwback.
And yes, Tesla does not handle this at all. It will happily plod along for tens of miles on a back country road at 30 mph because it didn't see a new speed limit sign, and it apparently now exclusively uses signs to change speed as opposed to speed limits in its map data. Just one more reason that universal robotaxis are not coming any time soon.
So yes Tesla doesn't understand an End of 35mph sign, just like I don't understand it. It's definitely not a standard marking unless a construction zone.
Yes, Tesla understands rural road speeds, but it doesn't know the State Speed limit law. That's because the map has the speeds marked and that's it's primary source of speed limit information. So yes, it seems as if the map info may be wrong, it is in many locations.
You are probably right on a 90 degree turn, that's an extreme that I haven't seen the car do extremely well at.
BUT, the car does see most curves and does slow down for them, often a little too slow for my preference. (It didn't do this years ago, car would just freak)
And no, it does not recognize the yellow speed limit signs. If you watch the display, they will not appear, whereas the white ones will. In my years of experience, the caution speeds are close to being a joke in most locations, as in "25 mph" for a turn that is safely navigated at 45.
While some (maybe most) have statewide "if not marked" speed limits, they aren't a great idea. How am I as a visitor supposed to know it. Especially when they ARE DIFFERENT in different states.
EVRider-FL
Active Member
The cautionary yellow signs are not speed limits, they’re suggestions, so the car doesn’t have to abide by them, even though that would be a good idea. The car does slow down for curves that it knows about, regardless of signage.
BitJam
Active Member
I recently upgraded from auto-pilot to FSDb 11.3.6 and I noticed something similar here in rural New Mexico.
Overall, FSDb is better with speed limits than AP was. On my way home there is a sharp turn with a 30 mph limit that I take at 25. AP thinks the limit is 45 mph which required fast reflexes if I was using AP. FSDb fixed that.
That turns into a straight stretch of clear road with a 30 mph limit that I usually take at 33 or 35 mph. With no speed limit signs and no changes in the road FSDb thinks the limit drops down to 25 momentarily and then goes back up to 30 which causes me to use the right scroll wheel several times to keep the car moving along.
I've seen these mysterious momentary changes to 25 mph in a few other places. It's only been with FSDb and not AP. Even with these glitches the speed limits with FSDb have been better here.
My guess is that incorrectly slowing down to 25 is safer than incorrectly trying to go 45 so they added this "err on the side of caution" feature to FSD since it's supposed to do most of the driving for you while AP is primarily intended for use on highways.
I attribute all those speed problems to bad map data. It would be great if we had wiki-like access to that data so we could throw corrections at it - with appropriate oversight, of course.
BitJam
Active Member
I agree. I'd love to be able to correct the speed limits even if it's only for my car.
Unfortunately, I think Tesla is still all-in on autonomous FSD so adding the ability to have manual fixes like this are not a priority. The trend is away from manual control and towards automation.
Or that Tesla uses an open source map platform that is editable and you are just assuming that you can't do anything?
RTPEV
Active Member
They do (or they did), but I have noticed that whereas in the past it seemed to honor map data (even though that was sometimes incomplete/inaccurate), nowadays my experience is that it seems to rely solely on street signs. Maybe that's not true everywhere, but it certainly is (for better of worse) in my experience.
It's definitely still using map data. But I think that a physical sign overrides it.
EVRider-FL
Active Member
I don’t know how it’s supposed to work, but that’s been my experience too. One example: after going through a toll both with a posted 5mph limit, the car doesn’t revert to the real speed limit unless it sees another speed limit sign, which could be a mile from the toll both.
RTPEV
Active Member
As I said, it may work differently in different regions, but on a recent trip to New York, where it previously had no trouble adjusting to rural speed limits, it now stays at 30mph along the entirety of country roads because New York uses the "END 30 ZONE" types of signs rather than "SPEED LIMIT 55".
Also along pretty much the entirety of I-81 in Pennsylvania, they have apparently moved to an entirely electronic sign scheme (presumably so they can dynamically lower the speed limit according to traffic/conditions). So now there are no regular speed limit signs, just electronic signs that tell you what the speed limit is. Trouble is, the car doesn't recognize these signs, so it seems to revert to the last regular sign it saw, which is either 55 or 45. I suppose you could make the assumption that technically with the new signs there is no set speed limit in the maps, but I suspect it's still listed as 65 in most online maps.
Interestingly, I-95 in Virginia now has electronic signs as well, but they are so realistic looking that the car DOES recognize them and honors them.
As has been stated END 30 ZONE are non-standard signs.
Yep, the car doesn't recognize the stupid variable speed signs. Something that some idiot in DOT came up with. We have them here in Atlanta as well. And they are stupid.
But they aren't a problem for the car. When they change the speed from 65 to 55mph, that car tends to handle it well. Why? That's because they decreased the speed to match the fact that cars couldn't go that fast. Again it's a stupid concept and waste of money.
Different states do different things. Some states do stupid things. For example, a number of times I've gone to Seattle from Sea-Tac. I get in the HOV lane, but want to exit it. I drive for miles and there is NEVER a change from solid white to dotted white line to my right. That's when I figured out that in Washington, it's okay to cross a solid white line. That's not the case in most every other state.
Here in Georgia, it's very specifically illegal to cross the white line to get out of the HOV lane.
USDOT has standards. Most of them are just obvious conventions. But some states decide to buck a simple convention. USDOT tends to use federal funding as their only carrot to keep the states inline. But too much politics has entered the USDOT these days and things are just getting messed up,
/off soapbox
philw1776
Member
I have the latest release. Phantom braking way down. Ride much smoother. Much better than unusable to me prior releases.
Some few remaining Issues:
Still misses some quite visible rural/suburban speed limit signs
Does not see or respond to yellow caution speed suggestion signs
If a STOP sign for a perpendicular road is slightly canted such that any aspect is visible, the car says it's stopping for stop sign
Enters highway exits at high speed
Some few remaining Issues:
Still misses some quite visible rural/suburban speed limit signs
Does not see or respond to yellow caution speed suggestion signs
If a STOP sign for a perpendicular road is slightly canted such that any aspect is visible, the car says it's stopping for stop sign
Enters highway exits at high speed
RTPEV
Active Member
As others have said, it will NEVER do this because these are only suggestions. The car will use its vision and map knowledge to judge an appropriate speed for these situations.
RTPEV
Active Member
They are certainly standard where they exist.
I'm not trying to defend whether they are appropriate or best practice, but it's simply not true that they are not standard. They may not be standard across the entire US, but the federal government doesn't have jurisdiction over local, county, and state roads, nor does anyone have a "US" driver's license. For better or worse, each state has its own unique rules, conventions, and standards.
Yes, but the problem is when ALL the signs are electronic, it doesn't handle it well. That's because you come into a city or other densely populated area and they reduce the speed limit down to 55 or even 45 with a physical sign. And then when you come out of the zone, it's an electronic sign that announces the start of the 65 speed zone, which the car doesn't recognize, so it assumes that the limit is still 55 or 45. Not a huge deal because I can just scroll wheel up the speed to what I want, but obviously this would be very bad for a driverless vehicle.
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