I have heard of small towns that generated income by running speed traps. There was a notorious one near where I am from where the speed limit changed like a dozen times seemingly randomly over the course of a couple miles. Maybe someday we will see some enterprising sheriff set up some trap for Tesla robotaxis and fund their local government by fining Elon. They can beta test it by sticking a cop at the nearest school right now!
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.
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.
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).
My understanding is that the 85 pct rule has fallen out of favor outside of highways (where the mode mix is 100% high power automobiles.) I know for my municipality and my state, we set speeds in denser areas based primarily on the mode mix and in less dense areas a balance between vehicle volumes, congestion in surrounding areas, and mode mix.
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.
> 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.
I actually look forward to self driving taxis/etc doing the speed limit for this reason. It's going to be difficult to speed if there are always vehicles doing the speed limits in various lanes (where passing lanes don't exist, at least)
As a software engineer I have no desire to ever let any sort of computer drive my car, and I will happily do what is required to maintain my access to the wheel. I'm thinking stuff like, more stringent driver exams, more expensive license renewals, that sort of thing. I recognize I'm an edge case and am prepared to contend with that however required. I am however also incredibly looking forward to a whole lot of other people being in self-driving cars, because my goodness, a large chunk of our populace has no business being behind the wheel.
Largely agree. As a fellow red blooded american, I love my freedoms as well, but looking at how other people drive on the road, I’ll know when self driving has been solved because insurance companies will charge very differently for cars driven manually than cars driven by software.
Maybe software will never get good enough, but that’s not a bet I would make.
I think the software will get good enough to be quite far ahead of the average driver here. They're not great and they're only getting worse in my experience.
That said I think a fair number of people, myself included, are fine to pay and do more to keep our hand-driven cars, and I'll happily drive next to (properly insured) robots.
Ok? When I was learning to drive, I was taught to drive safely, whether that was under the speed limit or not. As my dad put it, "would you rather be right or alive?"
Also, people generally self-regulate down to a speed that "feels safe" for the road at hand. Sometimes this itself causes problems (the HUGE suburban streets near me constantly have speeding cars, because again, the street is huge and wide lanes make people confident to drive faster) but again, the issue there is that you need to make the road narrower, and then drivers will naturally slow down.
These mechanisms among others are much more effective at traffic calming rather than putting up more damn signs to clutter things up, and hiring more cops. But of course fixing streets costs money, and police issuing fines generates it, so it's not shocking that most municipalities go with option B.
Not fixing streets is 'free' and reduces the perceived safe speed. Letting the streets crumble is a win win.
This doesn't entirely work, eventually the street gets unusable and it's often much more expensive to rebuild it than it you had done timely maintenance.
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.) Urban planning discourse about "stroads" in the US is largely a story of local roads that have eventually been classified as collectors or arterials so retain the residential or commercial density of a slower road but are expected to have the speeds and vehicle volumes of faster roads.
(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.)
"...the National Maximum Speed Limit (NMSL) was enacted in the 1974 Emergency Highway Energy Conservation Act that withheld Federal Highway funds from States that refused to comply with provisions of the law, including a maximum speed limit of 55 miles per hour (89 km/h) for passenger vehicles, an increase Nixon approved in signing the final legislation."
Heh there is lots of minutiae, but I'd argue that the NMSL is actually a very big part of transport history in the US and is absolutely something that people should read about. I actually think covering it should be part of basic US civics but :shrug: doubt that's going to happen.
There are an enormous number of 2 lane roads in school zones. When there's only one lane of travel in your direction, what's the argument that driving the speed limit could be dangerously slow?
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).
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?
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.
I have heard of small towns that generated income by running speed traps. There was a notorious one near where I am from where the speed limit changed like a dozen times seemingly randomly over the course of a couple miles. Maybe someday we will see some enterprising sheriff set up some trap for Tesla robotaxis and fund their local government by fining Elon. They can beta test it by sticking a cop at the nearest school right now!
Probably just re-enacting the training data.
Or running an experiment to create new training data.
Just couple of billions of miles of driving data more and they'll be good to go!
would rust have fixed this?
Certainly, as long as it’s on the car and there’s enough of it.
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.
A car should not have a “break the law” mode.
If speed limits are impractical they have to be fixed.
In some places, that's how speed limits are fixed.
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...
Doesn't that just cause speeds to creep up as people think it's okay to go a little over the limit?
We have the highest posted speed limit in the United States right now at 85mph for a 40-mile stretch in Austin - so you may be onto something.
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.
that's already priced in
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).
My understanding is that the 85 pct rule has fallen out of favor outside of highways (where the mode mix is 100% high power automobiles.) I know for my municipality and my state, we set speeds in denser areas based primarily on the mode mix and in less dense areas a balance between vehicle volumes, congestion in surrounding areas, and mode mix.
Lets not take advice about anything in regards to road safety from the US, or specially Texas.
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.
> 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.
I actually look forward to self driving taxis/etc doing the speed limit for this reason. It's going to be difficult to speed if there are always vehicles doing the speed limits in various lanes (where passing lanes don't exist, at least)
As a software engineer I have no desire to ever let any sort of computer drive my car, and I will happily do what is required to maintain my access to the wheel. I'm thinking stuff like, more stringent driver exams, more expensive license renewals, that sort of thing. I recognize I'm an edge case and am prepared to contend with that however required. I am however also incredibly looking forward to a whole lot of other people being in self-driving cars, because my goodness, a large chunk of our populace has no business being behind the wheel.
Largely agree. As a fellow red blooded american, I love my freedoms as well, but looking at how other people drive on the road, I’ll know when self driving has been solved because insurance companies will charge very differently for cars driven manually than cars driven by software.
Maybe software will never get good enough, but that’s not a bet I would make.
I think the software will get good enough to be quite far ahead of the average driver here. They're not great and they're only getting worse in my experience.
That said I think a fair number of people, myself included, are fine to pay and do more to keep our hand-driven cars, and I'll happily drive next to (properly insured) robots.
When I was learning to drive, I was taught to stay within the speed limit.
Ok? When I was learning to drive, I was taught to drive safely, whether that was under the speed limit or not. As my dad put it, "would you rather be right or alive?"
Also, people generally self-regulate down to a speed that "feels safe" for the road at hand. Sometimes this itself causes problems (the HUGE suburban streets near me constantly have speeding cars, because again, the street is huge and wide lanes make people confident to drive faster) but again, the issue there is that you need to make the road narrower, and then drivers will naturally slow down.
These mechanisms among others are much more effective at traffic calming rather than putting up more damn signs to clutter things up, and hiring more cops. But of course fixing streets costs money, and police issuing fines generates it, so it's not shocking that most municipalities go with option B.
> But of course fixing streets costs money
Not fixing streets is 'free' and reduces the perceived safe speed. Letting the streets crumble is a win win.
This doesn't entirely work, eventually the street gets unusable and it's often much more expensive to rebuild it than it you had done timely maintenance.
This is the justification you make to yourself. People drive the speed limit. I do, never had a speeding ticket. It has never been dangerous.
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.) Urban planning discourse about "stroads" in the US is largely a story of local roads that have eventually been classified as collectors or arterials so retain the residential or commercial density of a slower road but are expected to have the speeds and vehicle volumes of faster roads.
(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.)
And then read all the arbitrary historical minutia that have also influenced speed limits.
https://en.wikipedia.org/wiki/National_Maximum_Speed_Law
"...the National Maximum Speed Limit (NMSL) was enacted in the 1974 Emergency Highway Energy Conservation Act that withheld Federal Highway funds from States that refused to comply with provisions of the law, including a maximum speed limit of 55 miles per hour (89 km/h) for passenger vehicles, an increase Nixon approved in signing the final legislation."
Heh there is lots of minutiae, but I'd argue that the NMSL is actually a very big part of transport history in the US and is absolutely something that people should read about. I actually think covering it should be part of basic US civics but :shrug: doubt that's going to happen.
There are an enormous number of 2 lane roads in school zones. When there's only one lane of travel in your direction, what's the argument that driving the speed limit could be dangerously slow?
Sounds like a failed state in that regard.
*imperfect
Bro, you are in control. You arw in charge. If you hit a kid and kill it using FSD, you will be held accountable, not Tesla.
Stop using dangerous hw features.
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.
Thanks for the clarification, did you file a report?
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.
https://rosap.ntl.bts.gov/view/dot/27029
Who speeds in a school zone? It's like 1000ft of going slow so you don't hit a child
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.
There's one of those in the thread right now.
Where I live (Los Angeles), probably 90% of drivers
Especially when school is not in session and children are not present.
How much is that likely to bias the dataset?
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.
>Who speeds in a school zone?
Marques Brownlee
How could they say this but still claim it will be safer than humans?
Whether driving below the posted speed limit is safer than driving with a somewhat faster flow of traffic is a fuzzy, very contingent question.
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).
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?
That's your main worry? My worry is to hit a child that comes running from behind a vehicle.
On a Tesla robotaxi article, you're highlighting a Waymo incident when Waymo is approved for a fully driverless operation?
The risk of hitting a child is the reason that we have the school zones and the penalties to enforce them.
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.
Most school zones (if not all of them) should be eliminated.
I've never heard this take...why should we eliminate school zones?
Just think of the minutes of your life you'll never get back. 20 minutes of your entire life, poof, gone! And for what, safety?
counter point: don't speed.