7 ms·

The question is, if everyone is speeding, would it not make sense to raise the speed limit?

ndsipa_pomu 2y ago
That's just drivers normalising the breaking of the speed limits. If you raise the limits just because drivers are going faster, then the drivers will just increase their speeds until again, a majority of drivers are breaking the limit. Speed limits should be defined to reduce the harm from the inevitable crashes e.g. we have a lot of 20mph limits here in the UK in cities such as Bristol which are designed to reduce pedestrian deaths. Personally, I think roads are poorly designed - they often prioritise speed which then encourages drivers to go faster (e.g. long sight lines, sweeping corners etc) and then a speed limit is applied. I think the better alternative s to design roads so that drivers naturally travel slower, or at least the careful ones do.
- otteromkram 2y ago
  I dislike how you think. When I drive, 99% of the time it's to get someplace, not go for a Sunday cruise. The better alternative is ongoing driver training beyond initial study.
  - tfourb 2y ago
    Driving 10 mph above the speed limit on a highway at every opportunity will only lead to a very limited reduction in travel time, because you spend a lot of time breaking (i.e. to avoid crashing into law-abiding drivers, reacting to speed controls, etc.). At the same time it drastically increases both the risk of accidents, as well as the severity of accidents when they happen. You also endanger not only yourself but also everyone else on the road with you. Sensible road design takes this into account and constructs roads in a way that disincentivizes speeding and is safer for everyone. One example would be "lazily" meandering highways instead of perfectly straight ones. The broken sightline is a great incentive to keep your foot off the gas, most people do it instinctively. "Ongoing driver training" on the other hand is burdensome and expensive for the individual drivers and will probably lead to little noticeable effect, as speeding is not related to "not knowing better", but to "feeling entitled to break the rules" (for whatever reason).
    - echelon_musk 2y ago
      > breaking Braking
    - lupusreal 2y ago
      Failure to drive 70 mph on a highway posted at 60 will (very often, road depending) result in far more cars overpassing you. Each instance of passing carries a small but definite amount of risk; it is safer to match the speed of the other cars on the road than to obstinately stick to the limit and get passed hundreds of times in a single trip. (As for ripping up roads and relaying them so drivers intuitively find the safe speed to match the posted speed limit, it would be much cheaper to simply adjust the speed limit than establishing entirely new right of ways through existing neighborhoods, farms and industrial zones. That would be bonkers.)
      - ChoGGi 2y ago
        Everyone doing 60 doesn't see each other because we're all doing the same speed, the ones going faster are the dangerous drivers.
        ryao 2y ago
        When everyone is driving beyond the speed limit, the ones actually obeying the speed limit are the dangerous drivers. It is unfortunate that speed limits in the US have not corresponded to how people actually drive since 1973.
        tfourb 2y ago
        How does this make sense? If I'm driving the speed limit and someone else is crashing into me from behind while speeding, they are the dangerous driver. No matter how many other people also ignore the speed limit. Also, increasing the speed limit does nothing to make traffic safer. That doesn't make any sense at all, as increased speed is correlated very well with increased accident rates and severity of traffic-related injuries: https://road-safety.transport.ec.europa.eu/eu-road-safety-policy/priorities/safe-road-use/safe-speed/archive/speeding/speed-central-issue-road-safety/speed-and-injury-risk-different-speed-levels_en https://road-safety.transport.ec.europa.eu/eu-road-safety-po...
  - tonyedgecombe 2y ago
    That's the US philosophy and it's why road deaths per mile are so bad there. https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in_U.S._by_year#/media/File:1994-_Motor_vehicle_traffic_deaths_in_road_accidents,_by_country.svg https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in...
    - ryao 2y ago
      That is arguably more aligned with the German philosophy given the no speed limit autobahn and road deaths per mile are not so bad there.
- mschuster91 2y ago
  > I think the better alternative s to design roads so that drivers naturally travel slower, or at least the careful ones do. We're talking about long distance roads. The purpose of these should be to accommodate travel, not prohibit it. Here in Germany, the Autobahnen do a surprisingly well job, although I agree that a speed limit of around 200 km/h makes sense because those with cars capable of going above that are so much faster than others on the road that even someone with perfect reflexes and racing-grade brake systems will have a hard time avoiding an accident.
- lupusreal 2y ago
  > If you raise the limits just because drivers are going faster, then the drivers will just increase their speeds until again No. Most people who drive significantly faster than the limit are disregarding the limit and are driving at the speed they feel to be safe. They aren't considering the limit and blindly choosing to drive X over it, such that they'd drive X even faster even if the posted limit were raised by X. If a long flat and straight country road in good condition has a posted limit of 30 and most people instead do 60 (this is common in many parts of the country), they wouldn't start doing 120 if the limit were raised to 60 because "do double the posted limit" was not their objective in the first place. Their objective was "drive at the speed which is safe for this road" and the condition of the road didn't change, so that speed doesn't change. (The reason I know this to be true is because the proportion of drivers who speed on any given road varies wildly with the road. On some roads, 95% do substantially faster than the limit while on other roads that ratio is flipped around the other way. This demonstrates that speeds are being chosen by the condition and nature of the road, not derived in some way from the posted limits.)
  - lesuorac 2y ago
    > The reason I know this to be true is because the proportion of drivers who speed on any given road varies wildly with the road. Another way to arrive at this conclusion is that if the speed limit is both 65 for trucks and cars its trivially not the limit of how fast one can safely drive. And as expected, you see trucks going 65 while cars speed around them at 70+. And also the inability for people to use the pedal and the steering wheel at the same time resulting in large 15+ mph speed drops around a highly visible curve.
  - mlhpdx 2y ago
    > Their objective was "drive at the speed which is safe for this road" Not really. The problem people are not prioritizing safety, they are rushing in an ego fueled spasm of disobedience and disrespect.
bayindirh 2y ago
Nope, because people are overestimating themselves. I know a couple of people who can do 2x the speed limit relatively safely, but this is because they were race drivers in a previous life. However, not everyone (incl. me) has that reflexes and situational awareness all the time. Recently I got into an accident. A car changed into my lane completely unannounced, and I was blinded by a car in my front diagonal. The car "jumped" into my vision, I braked and hit them relatively slowly. Being slow, uphill and on a wet road helped all of us (the car took some of the damage by sliding). Consider this in a freeway at speed limit. We'd be hurt. Consider this at 1.5x speed limit, because everyone speeds, and we would be dead. Do not forget, the police found out that I had no wrongdoing and blame. It was impossible to see them, and they neglected to check their mirrors and signal a lane change, plus I had some distance to them and braked as hard as I could the moment I saw them, and I was going 50KM/h to begin with.
- ysavir 2y ago
  > Nope, because people are overestimating themselves. I know a couple of people who can do 2x the speed limit relatively safely, but this is because they were race drivers in a previous life. However, not everyone (incl. me) has that reflexes and situational awareness all the time. And even then, although the ex-race drivers can drive safely at high speeds, it doesn't mean other people can drive safely while other people are moving a racetrack speeds. The key to safety on the road is predictability. Any form of driving that reduces predictability, even if the unpredictable driver has the necessary skill for that form of driving, creates a dangerous situation because other drivers will react to that unpredictability in unpredictable ways, and likely lacking the skill to pull it off. What matters isn't the driving skill of the most skilled driver on the road, it's the skill level of the least skilled driver on the road.
  - bayindirh 2y ago
    Exactly. This is why I used the word "relatively" there. Moreover, a prominent race driver, happened to be a friend of my dad, died because of the same unpredictability of the traffic. Another race driver, whom I forgot his name, said "A race track is where people who know what they are doing drive at high speeds, and traffic is a race track where people don't know what they are doing, yet still drive at high speeds". I always keep that in mind and cite to other people to urge them to be careful in the traffic. What caused my accident was that unpredictability. A car changed lanes in front of me, without proper signaling and precautions from a point where it was impossible for me to see them.
lillecarl 2y ago
KE = ½mv² shows that kinetic energy is directly proportional to the mass of an object and proportional to the square of its velocity. This means that doubling the mass doubles the kinetic energy, but doubling the velocity quadruples the kinetic energy. The kinetic energy of an 1800 kg car traveling at 30 km/h is about 62.5 kJ The kinetic energy of an 1800 kg car traveling at 50 km/h is about 173.6 kJ The kinetic energy of an 1800 kg car traveling at 70 km/h is about 340.1 kJ... If your only consideration is getting to your destination very few minutes sooner with complete disregard for other peoples health it makes perfect sense, but cars are dangerous and at anything but completely isolated roads it makes sense to lower speed limits since the average speed wouldn't drop significantly while improving safety for everyone.
- socalgal2 2y ago
  This is the most annoying thing, they risk the lives of themselves and everyone around them and gain at most 1-2 minutes on 30 minute drive. It ridiculous how often someone speeds by, breaking the speed limit and often various other traffic laws and 30 seconds later we're side by side in traffic because their wreckless driving didn't actually but them any time.
  - bayindirh 2y ago
    My favorite pastime in traffic is to pull next to the person who was speeding and doing aggressive lane changes at the next red light by driving completely calm and under speed limit, and even without changing lanes.
- ryao 2y ago
  Consider how none of this matters if the vehicle never touches another object. If motorists reach their destinations sooner, then there are fewer cars on the road. This naturally increases the average distance between vehicles. Bad things only happen when those distances reach 0, so higher average distances inhibit collisions.
- mschuster91 2y ago
  > KE = ½mv² shows that kinetic energy is directly proportional to the mass of an object and proportional to the square of its velocity. This means that doubling the mass doubles the kinetic energy, but doubling the velocity quadruples the kinetic energy. You're wrong there, that assumption fundamentally only makes sense on a full-on hard crash to 0 km/h - and about the only cases where that happens on a German road are suicides or someone not recognizing a traffic jam. Most crashes on highways are at relatively close speeds so the energy delta is way, way smaller.
lupusreal 2y ago
This is correct. Laws should reflect the values of the democratic consensus, speed limits included. If almost everybody is traveling at a speed other than the posted speed limit, whether that's faster or slower, that is a strong signal that the speed limit needs to be adjusted. Speed limits should be set such that most people naturally think the limit is a sensible speed to drive anyway. As it is, speed limits are rarely set to the individual roads specific circumstance according to some sort of scientific or engineering method, instead most speed limits are set to a default speed used for that class of road across the state. As such, it is silly to act like extant speed limits are all correct even when nearly everybody is ignoring the limit on a specific road, evaluating that road's condition for themselves and choosing to drive at another speed.
- ysavir 2y ago
  So if most people keep speeding past the elementary school and kindergarten, we should raise the speed limit on that street?
  - mschuster91 2y ago
    These are objectively endangered places. A highway in the middle of nowhere, with reasonably well maintained roads and even terrain however?
    - ysavir 2y ago
      Sure, but the parent comment didn't leave any room for nuance or considerations, instead broadly stating: > Laws should reflect the values of the democratic consensus, speed limits included. Maybe they considered the nuance to be something obvious, but their statement is still flawed. The funny thing about nuance is that most nuance isn't visible to the naked eye and requires some degree of familiarity or expertise to observe. And that degree is why we shouldn't be assigning speed limits based on what the average driver thinks is appropriate for a given road, as more likely than not (much more likely than not) they don't have the necessary context to make an appropriate judgement.
CogitoCogito 2y ago
A similar method is in indeed used in many jurisdictions: https://en.wikipedia.org/wiki/Speed_limit#Operating_speed https://en.wikipedia.org/wiki/Speed_limit#Operating_speed There are advantages and disadvantages as with everything.
UncleMeat 2y ago
The number of people I see on the highway driving 20mph over and weaving through traffic or driving like 30ft behind the car in front of them is alarming. These behaviors are just simply less safe.
ryao 2y ago
It does make sense. See the 85th percentile speed: https://duckduckgo.com/?q=85th+percentile+speed https://duckduckgo.com/?q=85th+percentile+speed Setting the limit at the 85th percentile and having most drivers drive at it creates uniformity of speed, which is known to increase safety.
CalRobert 2y ago
This makes sense until they mow down a pedestrian just trying to cross the street.

That's just drivers normalising the breaking of the speed limits. If you raise the limits just because drivers are going faster, then the drivers will just increase their speeds until again, a majority of drivers are breaking the limit. Speed limits should be defined to reduce the harm from the inevitable crashes e.g. we have a lot of 20mph limits here in the UK in cities such as Bristol which are designed to reduce pedestrian deaths. Personally, I think roads are poorly designed - they often prioritise speed which then encourages drivers to go faster (e.g. long sight lines, sweeping corners etc) and then a speed limit is applied. I think the better alternative s to design roads so that drivers naturally travel slower, or at least the careful ones do.

otteromkram 2y ago
I dislike how you think. When I drive, 99% of the time it's to get someplace, not go for a Sunday cruise. The better alternative is ongoing driver training beyond initial study.
- tfourb 2y ago
  Driving 10 mph above the speed limit on a highway at every opportunity will only lead to a very limited reduction in travel time, because you spend a lot of time breaking (i.e. to avoid crashing into law-abiding drivers, reacting to speed controls, etc.). At the same time it drastically increases both the risk of accidents, as well as the severity of accidents when they happen. You also endanger not only yourself but also everyone else on the road with you. Sensible road design takes this into account and constructs roads in a way that disincentivizes speeding and is safer for everyone. One example would be "lazily" meandering highways instead of perfectly straight ones. The broken sightline is a great incentive to keep your foot off the gas, most people do it instinctively. "Ongoing driver training" on the other hand is burdensome and expensive for the individual drivers and will probably lead to little noticeable effect, as speeding is not related to "not knowing better", but to "feeling entitled to break the rules" (for whatever reason).
  - echelon_musk 2y ago
    > breaking Braking
  - lupusreal 2y ago
    Failure to drive 70 mph on a highway posted at 60 will (very often, road depending) result in far more cars overpassing you. Each instance of passing carries a small but definite amount of risk; it is safer to match the speed of the other cars on the road than to obstinately stick to the limit and get passed hundreds of times in a single trip. (As for ripping up roads and relaying them so drivers intuitively find the safe speed to match the posted speed limit, it would be much cheaper to simply adjust the speed limit than establishing entirely new right of ways through existing neighborhoods, farms and industrial zones. That would be bonkers.)
    - ChoGGi 2y ago
      Everyone doing 60 doesn't see each other because we're all doing the same speed, the ones going faster are the dangerous drivers.
      - ryao 2y ago
        When everyone is driving beyond the speed limit, the ones actually obeying the speed limit are the dangerous drivers. It is unfortunate that speed limits in the US have not corresponded to how people actually drive since 1973.
        tfourb 2y ago
        How does this make sense? If I'm driving the speed limit and someone else is crashing into me from behind while speeding, they are the dangerous driver. No matter how many other people also ignore the speed limit. Also, increasing the speed limit does nothing to make traffic safer. That doesn't make any sense at all, as increased speed is correlated very well with increased accident rates and severity of traffic-related injuries: https://road-safety.transport.ec.europa.eu/eu-road-safety-policy/priorities/safe-road-use/safe-speed/archive/speeding/speed-central-issue-road-safety/speed-and-injury-risk-different-speed-levels_en https://road-safety.transport.ec.europa.eu/eu-road-safety-po...
- tonyedgecombe 2y ago
  That's the US philosophy and it's why road deaths per mile are so bad there. https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in_U.S._by_year#/media/File:1994-_Motor_vehicle_traffic_deaths_in_road_accidents,_by_country.svg https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in...
  - ryao 2y ago
    That is arguably more aligned with the German philosophy given the no speed limit autobahn and road deaths per mile are not so bad there.
mschuster91 2y ago
> I think the better alternative s to design roads so that drivers naturally travel slower, or at least the careful ones do. We're talking about long distance roads. The purpose of these should be to accommodate travel, not prohibit it. Here in Germany, the Autobahnen do a surprisingly well job, although I agree that a speed limit of around 200 km/h makes sense because those with cars capable of going above that are so much faster than others on the road that even someone with perfect reflexes and racing-grade brake systems will have a hard time avoiding an accident.
lupusreal 2y ago
> If you raise the limits just because drivers are going faster, then the drivers will just increase their speeds until again No. Most people who drive significantly faster than the limit are disregarding the limit and are driving at the speed they feel to be safe. They aren't considering the limit and blindly choosing to drive X over it, such that they'd drive X even faster even if the posted limit were raised by X. If a long flat and straight country road in good condition has a posted limit of 30 and most people instead do 60 (this is common in many parts of the country), they wouldn't start doing 120 if the limit were raised to 60 because "do double the posted limit" was not their objective in the first place. Their objective was "drive at the speed which is safe for this road" and the condition of the road didn't change, so that speed doesn't change. (The reason I know this to be true is because the proportion of drivers who speed on any given road varies wildly with the road. On some roads, 95% do substantially faster than the limit while on other roads that ratio is flipped around the other way. This demonstrates that speeds are being chosen by the condition and nature of the road, not derived in some way from the posted limits.)
- lesuorac 2y ago
  > The reason I know this to be true is because the proportion of drivers who speed on any given road varies wildly with the road. Another way to arrive at this conclusion is that if the speed limit is both 65 for trucks and cars its trivially not the limit of how fast one can safely drive. And as expected, you see trucks going 65 while cars speed around them at 70+. And also the inability for people to use the pedal and the steering wheel at the same time resulting in large 15+ mph speed drops around a highly visible curve.
- mlhpdx 2y ago
  > Their objective was "drive at the speed which is safe for this road" Not really. The problem people are not prioritizing safety, they are rushing in an ego fueled spasm of disobedience and disrespect.

bayindirh 2y ago

Nope, because people are overestimating themselves. I know a couple of people who can do 2x the speed limit relatively safely, but this is because they were race drivers in a previous life. However, not everyone (incl. me) has that reflexes and situational awareness all the time. Recently I got into an accident. A car changed into my lane completely unannounced, and I was blinded by a car in my front diagonal. The car "jumped" into my vision, I braked and hit them relatively slowly. Being slow, uphill and on a wet road helped all of us (the car took some of the damage by sliding). Consider this in a freeway at speed limit. We'd be hurt. Consider this at 1.5x speed limit, because everyone speeds, and we would be dead. Do not forget, the police found out that I had no wrongdoing and blame. It was impossible to see them, and they neglected to check their mirrors and signal a lane change, plus I had some distance to them and braked as hard as I could the moment I saw them, and I was going 50KM/h to begin with.

ysavir 2y ago
> Nope, because people are overestimating themselves. I know a couple of people who can do 2x the speed limit relatively safely, but this is because they were race drivers in a previous life. However, not everyone (incl. me) has that reflexes and situational awareness all the time. And even then, although the ex-race drivers can drive safely at high speeds, it doesn't mean other people can drive safely while other people are moving a racetrack speeds. The key to safety on the road is predictability. Any form of driving that reduces predictability, even if the unpredictable driver has the necessary skill for that form of driving, creates a dangerous situation because other drivers will react to that unpredictability in unpredictable ways, and likely lacking the skill to pull it off. What matters isn't the driving skill of the most skilled driver on the road, it's the skill level of the least skilled driver on the road.
- bayindirh 2y ago
  Exactly. This is why I used the word "relatively" there. Moreover, a prominent race driver, happened to be a friend of my dad, died because of the same unpredictability of the traffic. Another race driver, whom I forgot his name, said "A race track is where people who know what they are doing drive at high speeds, and traffic is a race track where people don't know what they are doing, yet still drive at high speeds". I always keep that in mind and cite to other people to urge them to be careful in the traffic. What caused my accident was that unpredictability. A car changed lanes in front of me, without proper signaling and precautions from a point where it was impossible for me to see them.

lillecarl 2y ago

KE = ½mv² shows that kinetic energy is directly proportional to the mass of an object and proportional to the square of its velocity. This means that doubling the mass doubles the kinetic energy, but doubling the velocity quadruples the kinetic energy. The kinetic energy of an 1800 kg car traveling at 30 km/h is about 62.5 kJ The kinetic energy of an 1800 kg car traveling at 50 km/h is about 173.6 kJ The kinetic energy of an 1800 kg car traveling at 70 km/h is about 340.1 kJ... If your only consideration is getting to your destination very few minutes sooner with complete disregard for other peoples health it makes perfect sense, but cars are dangerous and at anything but completely isolated roads it makes sense to lower speed limits since the average speed wouldn't drop significantly while improving safety for everyone.

socalgal2 2y ago
This is the most annoying thing, they risk the lives of themselves and everyone around them and gain at most 1-2 minutes on 30 minute drive. It ridiculous how often someone speeds by, breaking the speed limit and often various other traffic laws and 30 seconds later we're side by side in traffic because their wreckless driving didn't actually but them any time.
- bayindirh 2y ago
  My favorite pastime in traffic is to pull next to the person who was speeding and doing aggressive lane changes at the next red light by driving completely calm and under speed limit, and even without changing lanes.
ryao 2y ago
Consider how none of this matters if the vehicle never touches another object. If motorists reach their destinations sooner, then there are fewer cars on the road. This naturally increases the average distance between vehicles. Bad things only happen when those distances reach 0, so higher average distances inhibit collisions.
mschuster91 2y ago
> KE = ½mv² shows that kinetic energy is directly proportional to the mass of an object and proportional to the square of its velocity. This means that doubling the mass doubles the kinetic energy, but doubling the velocity quadruples the kinetic energy. You're wrong there, that assumption fundamentally only makes sense on a full-on hard crash to 0 km/h - and about the only cases where that happens on a German road are suicides or someone not recognizing a traffic jam. Most crashes on highways are at relatively close speeds so the energy delta is way, way smaller.

lupusreal 2y ago

This is correct. Laws should reflect the values of the democratic consensus, speed limits included. If almost everybody is traveling at a speed other than the posted speed limit, whether that's faster or slower, that is a strong signal that the speed limit needs to be adjusted. Speed limits should be set such that most people naturally think the limit is a sensible speed to drive anyway. As it is, speed limits are rarely set to the individual roads specific circumstance according to some sort of scientific or engineering method, instead most speed limits are set to a default speed used for that class of road across the state. As such, it is silly to act like extant speed limits are all correct even when nearly everybody is ignoring the limit on a specific road, evaluating that road's condition for themselves and choosing to drive at another speed.

ysavir 2y ago
So if most people keep speeding past the elementary school and kindergarten, we should raise the speed limit on that street?
- mschuster91 2y ago
  These are objectively endangered places. A highway in the middle of nowhere, with reasonably well maintained roads and even terrain however?
  - ysavir 2y ago
    Sure, but the parent comment didn't leave any room for nuance or considerations, instead broadly stating: > Laws should reflect the values of the democratic consensus, speed limits included. Maybe they considered the nuance to be something obvious, but their statement is still flawed. The funny thing about nuance is that most nuance isn't visible to the naked eye and requires some degree of familiarity or expertise to observe. And that degree is why we shouldn't be assigning speed limits based on what the average driver thinks is appropriate for a given road, as more likely than not (much more likely than not) they don't have the necessary context to make an appropriate judgement.

CogitoCogito 2y ago

A similar method is in indeed used in many jurisdictions: https://en.wikipedia.org/wiki/Speed_limit#Operating_speed https://en.wikipedia.org/wiki/Speed_limit#Operating_speed There are advantages and disadvantages as with everything.

UncleMeat 2y ago

The number of people I see on the highway driving 20mph over and weaving through traffic or driving like 30ft behind the car in front of them is alarming. These behaviors are just simply less safe.

ryao 2y ago

It does make sense. See the 85th percentile speed: https://duckduckgo.com/?q=85th+percentile+speed https://duckduckgo.com/?q=85th+percentile+speed Setting the limit at the 85th percentile and having most drivers drive at it creates uniformity of speed, which is known to increase safety.

CalRobert 2y ago

This makes sense until they mow down a pedestrian just trying to cross the street.