My FSD 14.3 car definitely does NOT respect school zones. Maybe I’m weird, but whether or not I have the car in “Hurry” mode, I expect a hard cutoff at speed limit for a school zone of myself or anything acting on my behalf. I could understand the semantics around “Mad Max” not respecting the signage, but still. Bro. Slow down in a school zone.
That … is definitely not how things work in the US. Municipalities set speed limits based on a variety of things including but not limited to maximizing revenue, the streets city council members live on, random news reports about speeds in adjacent jurisdictions, and so on.
Were a car to refuse to exceed the speed limit, it would be dangerously slow almost everywhere in the united states, arguably reducing safety substantially.
This is a very weird argument. How can a car be dangerously slow if all the other cars stick to the speed limit as well? Any danger can only come from a difference in speed. So the danger is actually not the car observing the speed limit, it is the other cars that do not. Notably, any reduction in danger that flows from breaking the speed limit is only for the car and other cars breaking the speed limit, in no case it is for pedestrians, cyclists or other non-vehicle participants in traffic.
> How can a car be dangerously slow if all the other cars stick to the speed limit as well?
Because the other cars are speeding too.
> Notably, any reduction in danger that flows from breaking the speed limit is only for the car and other cars breaking the speed limit, in no case it is for pedestrians, cyclists or other non-vehicle participants in traffic.
Correct.
Speed limits in a vacuum are largely about revenue generation. There's ample evidence backing numerous practices that actually slow traffic, things like using traffic circles instead of intersections, reducing the width of lanes to promote slower travel, speed humps, separating traffic that's going a distance (roads) at speed, from slower traffic preparing to enter residences/businesses (streets). Lots of stuff.
Limits though? I mean they probably don't do nothing but they aren't nearly as effective unless you pair them with a regular police presence. And even then, mixed effects. I'm pretty sure the entirety of the Chicago Loop is capped at 55 mph, but if you actually do 55 on that thing, you're gonna die.
As to the topic of the thread: truthfully, IMO, parents should be barred from ferrying their kids to school. Not only is it just a "commute but worse" in terms of ecological impact (the car goes, drops the person, returns home, then returns later, picks up, and returns home. Literally 2x the normal traffic impact) but also it's ridiculously inefficient for similar reasons. School traffic everywhere I have ever lived has been a goddamned nightmare. I would rather be stuck on the highway jam ten times than be trying to navigate around a school full of stressed, harried parents driving big stupid SUVs, who themselves are surrounded by children, who themselves are entering and exiting vehicles at random.
School busses are the safest vehicles on American roads, and starting kids on them early gets them comfortable with the idea of mass transit. Dictionary definition of a win/win.
If folks are actually interested in how speed limits are set in American cities, I'd encourage them to read about the process in their municipality rather than absorbing information from message board conspiracy posts. In practice, there are indeed several competing pressures that dictate speed limits.
One source of pressure to keep speeds high is that if municipalities can classify a street as a collector or arterial, they can get federal aid for projects related to the road. As such cities will often want to bring a local road up to collector or arterial status so that they can get higher federal funding for it. (Collectors and arterials usually are larger streets with higher speed limits, though the biggest gray zone is between collectors and local roads and often the biggest difference is indeed the speed limit.)
(FWIW I first saw this on city-data in the early 2000s and vaguely heard my parents' generation say similar things to this comment, but when I actually started listening and attending local meetings I realize that it's mostly an urban legend that gets repeated to each other.)
This link claims this is for highways. Does TxDOT have a wider criteria for "highway" than the standard FHWA criteria? Under FHWA I would presume that school roads would be found on local or collector roads, not highways, but I'm not familiar with the streets mix nor the grant landscape of Texas cities.
Yes, there are different criteria for different roads. Presence of schools is one of them. In my neighborhood, the speed limit drops to 25 mph through school zones (it's 40-45 mph outside of the school zone).
Generally, there are 2 forces at play dictating how fast people will go on a given road. The probability of getting caught speeding is one, the other is the perceived safety of going fast. The issue most American roads have is that they are built extremely wide, with even more open space on either side of the road, so people are comfortable gunning it. Speed limits only matter insomuch as they adjust the perceived probability of being pulled over.
Our highways also train you that speed limit are complete bullshit. On an 8 lane, divided highway, with nothing but empty field or protective barriers on either side, 60 mph is comically low. That's how you end up with absurdities like it often being unavoidably illegal to drive on 680 in the Bay Area: either you're speeding, or you're obstructing traffic, both of which carry a fine.
IMO, the correct answer is to raise the speed limit of surface streets that already double as psuedo-highways (looking at you, San Jose), strictly enforce speed limits on surface streets, and then completely eliminate speed limits on the freeways.
My google-fu is failing me right now so it might be apocryphal, but I once read a story about a man who got an obstruction of traffic ticket for doing the speed limit in the fast lane of the 401 in Toronto (the busiest & widest freeway in North America). He was doing so in protest of getting a speeding ticket for doing 40km/h over the limit in the merge lane.l
The amount that people go over the speed limit varies depending on the road conditions, what they think is safe, and what the speed limit is.
So, if a road feels "safe" at 60mph to people, and you put the speed limit as 20 the average traffic might be 40mph. If you put the speed limit as 40mph, it might go up to 55mph. If you put the speed limit as 60mph, it might go up to 65 mph.
But that natural tapering is what lets you find a stable value for a specific percentile threshold.
Well you may have read the very precise formulation I used acknowledging this very fact — this is software I’m deploying on my behalf, and it does not do what I expect in this case, so I choose not to use it in those circumstances.
Tesla/Musk has stated many times that FSD will follow common practice rather than follow the letter of the law. Over 90% of Americans speed in school zones, so FSD is presumably programmed to also do so.
There was a commenter on a similar article a few months ago arguing that speed limits being excessively low is just for trapping drivers and there's no reason for there to ever be speed limits below 30mph.
That's the kind of person I expect who speeds in a school zone.
Same in Oxnard, they put a school zone on a divided ave. No one slows down. And there's a bus stop on either side so if everyone obeyed the "when children present" it would be a huge bottleneck. Even cops fly through it.
True, but gently slowing down on a residential street near a school feels unlikely to lead to other drivers attempting high speed tailgating, undertaking or other aggressive manoeuvres that might result from, say, hogging the overtaking lane without actually overtaking because you're sticking to the speed limit, even before the obvious downsides of speeding near schools are considered...
(Also, the second case is something a car manufacturer should probably be resolving more by not hogging the overtaking lane than defaulting to going 20mph over the limit for extended periods because everybody else does)
Not that the speeding is justified, but I would still bet on the computer continuously processing multiple video feeds reacting and stopping quicker than a human in almost all incidents.
Waymo takes safety way more (no pun intended) seriously than Tesla, and they still hit a kid in a school zone, because that's a very challenging environment: there are parked cars, the density of kids who might dart out into the road from behind them is way higher than normal, etc. You should apply a higher level of caution in school zones even if you have an advanced sensor suite (and Tesla doesn't since they insist on doing everything via cameras).
Tens of thousands dead in traffic due to the “common practice” of driving unsafely. We have the opportunity here to make the roads safe but apparently mr musk doesn’t see the need.
I hope the Nordics prevail and the Europeans don’t follow his bullshit.
As a normal human citizen, speeding in a school zone carries a risk of a significant ticket, with repeat offenses adding points until my license is suspended.
What consequences does Elon Musk face when his autonomous cars do the same?
It will be approved it seems, but there will be a condition that you cannot speed more than 10% of above the limit. Which still for me is hard to understand why you then don’t just raise the limit if you think that going 10% above the law is fine?
If speed limits are impractical they have to be fixed.
Were a car to refuse to exceed the speed limit, it would be dangerously slow almost everywhere in the united states, arguably reducing safety substantially.
Because the other cars are speeding too.
> Notably, any reduction in danger that flows from breaking the speed limit is only for the car and other cars breaking the speed limit, in no case it is for pedestrians, cyclists or other non-vehicle participants in traffic.
Correct.
Speed limits in a vacuum are largely about revenue generation. There's ample evidence backing numerous practices that actually slow traffic, things like using traffic circles instead of intersections, reducing the width of lanes to promote slower travel, speed humps, separating traffic that's going a distance (roads) at speed, from slower traffic preparing to enter residences/businesses (streets). Lots of stuff.
Limits though? I mean they probably don't do nothing but they aren't nearly as effective unless you pair them with a regular police presence. And even then, mixed effects. I'm pretty sure the entirety of the Chicago Loop is capped at 55 mph, but if you actually do 55 on that thing, you're gonna die.
As to the topic of the thread: truthfully, IMO, parents should be barred from ferrying their kids to school. Not only is it just a "commute but worse" in terms of ecological impact (the car goes, drops the person, returns home, then returns later, picks up, and returns home. Literally 2x the normal traffic impact) but also it's ridiculously inefficient for similar reasons. School traffic everywhere I have ever lived has been a goddamned nightmare. I would rather be stuck on the highway jam ten times than be trying to navigate around a school full of stressed, harried parents driving big stupid SUVs, who themselves are surrounded by children, who themselves are entering and exiting vehicles at random.
School busses are the safest vehicles on American roads, and starting kids on them early gets them comfortable with the idea of mass transit. Dictionary definition of a win/win.
One source of pressure to keep speeds high is that if municipalities can classify a street as a collector or arterial, they can get federal aid for projects related to the road. As such cities will often want to bring a local road up to collector or arterial status so that they can get higher federal funding for it. (Collectors and arterials usually are larger streets with higher speed limits, though the biggest gray zone is between collectors and local roads and often the biggest difference is indeed the speed limit.)
(FWIW I first saw this on city-data in the early 2000s and vaguely heard my parents' generation say similar things to this comment, but when I actually started listening and attending local meetings I realize that it's mostly an urban legend that gets repeated to each other.)
In Texas, for example, they do a traffic study and set the limit to the 85th percentile speed.
https://www.txdot.gov/safety/driving-laws/speed-limits/speed...
Our highways also train you that speed limit are complete bullshit. On an 8 lane, divided highway, with nothing but empty field or protective barriers on either side, 60 mph is comically low. That's how you end up with absurdities like it often being unavoidably illegal to drive on 680 in the Bay Area: either you're speeding, or you're obstructing traffic, both of which carry a fine.
IMO, the correct answer is to raise the speed limit of surface streets that already double as psuedo-highways (looking at you, San Jose), strictly enforce speed limits on surface streets, and then completely eliminate speed limits on the freeways.
So, if a road feels "safe" at 60mph to people, and you put the speed limit as 20 the average traffic might be 40mph. If you put the speed limit as 40mph, it might go up to 55mph. If you put the speed limit as 60mph, it might go up to 65 mph.
But that natural tapering is what lets you find a stable value for a specific percentile threshold.
Stop using dangerous hw features.
https://rosap.ntl.bts.gov/view/dot/27029
That's the kind of person I expect who speeds in a school zone.
(Also, the second case is something a car manufacturer should probably be resolving more by not hogging the overtaking lane than defaulting to going 20mph over the limit for extended periods because everybody else does)
I hope the Nordics prevail and the Europeans don’t follow his bullshit.
What consequences does Elon Musk face when his autonomous cars do the same?