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There’s too much focus on the easy to measure speed problem. I’m not saying inappropriate speed should not be enforced against but i strongly believe more effor

There’s too much focus on the easy to measure speed problem. I’m not saying inappropriate speed should not be enforced against but i strongly believe more effort should be applied to avoid the more common cause of major road traffic incidents - inattention. You can’t easily measure inattention but that doesn’t mean you shouldn’t try. The solution doesn’t only have to be in penalties, it could be in making it harder to be inattentive to begin with. That said, this is all low priority stuff in the UK. In the UK today there are basically zero road traffic police, you are exceedingly unlikely to come across any. Their numbers have been cut relentlessly as miles driven have increased. And yet... road deaths are down over the same 20 years and mobility is up. Road traffic enforcement isn’t even in the top 1000 issues facing the UK today.

yholio 6y ago
Inattention is hard to measure and results in accidents that are made much worse by excessive speed, which is easy to measure. If the goal is to reduce overall traffic victims, then investing in speed control seems like the low hanging fruit. The energy of vehicle (thus, the energy absorbed during impact by every object contained or hit) is proportinal with the square of the speed. Meanwhile, the reaction time available to avoid the collision drops linearly with speed, while the braking or turn distance increases more than linearly. So the overall probability of accidents and their severity increases exponentially with speed.
- Silhouette 6y ago
  The problem is that naive arguments about speed and laws based on fixed numbers don't really help anything except ease of prosecution. Inappropriate choice of speed can obviously be dangerous, but what is appropriate to the conditions and what the fixed numerical speed limits dictate can be wildly different. For example, the default speed limit in the UK on most residential roads is 30mph, but if you drive past a school at 30mph at the end of the afternoon when the kids are coming out and there are lots parked cars obscuring your view, that is still inappropriately fast for the conditions. However, slower isn't always safer. On a motorway, the speed limit is usually 70mph, but in poor weather conditions and heavy traffic, everyone travelling at lower and similar speeds may be the safest choice. If you're the one driver insisting on unnecessarily doing 20mph when everyone else is doing a steady 40mph, you're also increasing the danger to yourself and others. Another example is that the speed limit for heavy goods vehicles on many of our major roads was increased by 10mph in 2015, having previously been 20mph below what cars were allowed to do on the same roads. The results were notable for several reasons, among them that the actual average speed of those heavy vehicles only increased a little but the safety of the roads appears to have increased. This was attributed primarily to closing the gap in speeds between different types of vehicle and thus, among other things, reducing instances of queues behind and overtaking of the slower vehicles, both of which increase the risk of an accident. Finally, we have the classic motorway speeding situation, where on an open road in good conditions, a competent driver with a suitable vehicle could do far more than the legal limit of 70mph with negligible increase in risk. Moreover, statistically our motorways are both our fastest roads and yet also among our safest. You could certainly print money by setting up a covert speed camera watching some stretches of motorway, but whether it is a good use of police resources if your objective is to increase road safety is a different question.
- CraigJPerry 6y ago
  >> results in accidents that are made much worse by excessive speed Sure but there's no free lunch here. If you trade off speed in the non-accident cases, which is by far the majority of all miles driven, then there's a cost to that. It happens to be a really hard to measure cost so it's always completely ignored. How would you even begin to measure the cost to the nation of traffic arriving 5 minutes later? Not all 5 minute delays are equal, e.g the cost of delay to an ambulance rushing to hospital is different to the increased cost of delivering packages. >> the reaction time available In fairness, you could make the reaction time measurable in hours and it'd be insufficient to prevent some inattention caused road incidents. Another problem with only looking at speed is the unintended consequence of drivers de-rating the risks. E.g. if a vehicle was limited to 5mph, this as you know is slow enough to be fairly unlikely to cause a pedestrian death even if there is an impact, it would have the un-wanted effect that some drivers would view the risks as lower and would be inclined to engage in more risky behaviours, e.g. taking their eyes off the road to turn around and argue with a child in the back seat where in 20mph traffic they might choose instead to just speak to the child. >> So the overall probability of accidents No that doesn't hold. We don't have more accidents on the fastest roads in the UK.
  - yholio 6y ago
    > the cost to the nation of traffic arriving 5 minutes later? Traffic delays are dominated by congestion and road capacity does not increase with higher speeds. Once you hit the peak for that road section, trafic grinds. If, for example, you have a 30 minute comute that spends 15 minutes in congestion-limited trafic and 15 minutes on a speed limited empty highway, you would need to drive 50% faster on those sections to recoup a full 5 minutes, so something like 105 mph on a 70 mph section for a full 10 minutes. That doesn't sound realistic. There is a cost to low speed limits, clearly, but it is usually marginal - and when it's not, you should address that specific problem of a too low speed limit instead of making speed limits unenforceable throughout. If a section generates lots of speed tickets and no even minor incidents, it's clearly a sign to increase speed. > drivers de-rating the risks. True, but the risk rating they assigned to higher speeds was probably not proportional to the actual exponential increase to begin with. > We don't have more accidents on the fastest roads in the UK. That's moving the goal posts. The increase in risk is exponential on any given single road. Some roads are exceptionally safe at low speeds so you can increase the speed quite a bit and keep the risks low, hence the higher limits.
Shivetya 6y ago
It has not been all that long that we had technologies we could put into cars to determine if a driver was paying attention; though exactly what that is is also subject to interpretation With my Tesla I am able to have it chime if I exceed the speed limit by a set amount and even if a light turns green. however the big danger is still cell phone usage and no one wants to take the step of disabling them while moving and the technology is there.
- CraigJPerry 6y ago
  >> however the big danger is still cell phone usage There’s more than just cell phone usage. Inattention comes in many forms and none of them is better or worse than the others. Drivers paying more attention to the radio show they’re listening to while gently zoning out to the traffic conditions around them - this is really common on long motorway journeys. Drivers fizzing with rage at the argument they just had before getting in the car. Etc etc
lmm 6y ago
> And yet... road deaths are down over the same 20 years and mobility is up. > Road traffic enforcement isn’t even in the top 1000 issues facing the UK today. Road collisions are one of the biggest killers of young people in the UK. It's absolutely a big issue.
- CraigJPerry 6y ago
  What’s the bigger issue: road traffic enforcement or avoiding pedestrian deaths by finding acceptable ways to remove vehicles altogether from pedestrian areas? Road traffic enforcement or reducing infant asthma in cities by moving tailpipe emissions away from populated areas? Road traffic enforcement or ... you get the point.
  - lmm 6y ago
    If we're not able to enforce existing rules then it's hard to see how introducing new rules could ever help anything.
    - CraigJPerry 6y ago
      Who’s suggesting adding new rules?
      - lmm 6y ago
        Well what are you suggesting then? I think enforcing the traffic laws we have is one of the low-hanging fruit for cutting the huge rate of deaths from traffic collisions. Are you proposing something concrete that would be better to spend our time on, or just finding an excuse to do nothing?
        CraigJPerry 6y ago
        Every death should be avoided which should go without saying but this is the internet... >> huge rate We don't have huge rates compared to other countries - we're usually in the top 3 major developed countries every year for almost a decade at this point. We also don't have huge rates compared to other causes, e.g. there are under 2,000 road deaths each year but suicides top 6,500 per year. >> Are you proposing something concrete that would be better to spend our time on Yes - the solution for 0 road deaths does not exist purely in speed. Further, focussing only on speed has detrimental cost to the country. It's impossible to measure this cost so people ignore it. It is not sound methodology to ignore something simply because it can't be measured. As i stated upfront, enforcement of inappropriate speed should not be stopped, however, the biggest cause of road fatalaties - inattention - should now become a priority for enforcement. There is no technical gizmo available today for this therefore this means simply investing in more traffic police. No more complicated than that. I would expect though that some budget diverted from speed enforcement (which is a cost activity to the country despite the revenue it generates) would also be directed to figuring out more efficient ways of enforcing inattention. As i also said up front - this doesn't have to be in penalties, it might be better invested in making it less likely for drivers to be inattentive.

yholio 6y ago

Inattention is hard to measure and results in accidents that are made much worse by excessive speed, which is easy to measure. If the goal is to reduce overall traffic victims, then investing in speed control seems like the low hanging fruit. The energy of vehicle (thus, the energy absorbed during impact by every object contained or hit) is proportinal with the square of the speed. Meanwhile, the reaction time available to avoid the collision drops linearly with speed, while the braking or turn distance increases more than linearly. So the overall probability of accidents and their severity increases exponentially with speed.

Silhouette 6y ago
The problem is that naive arguments about speed and laws based on fixed numbers don't really help anything except ease of prosecution. Inappropriate choice of speed can obviously be dangerous, but what is appropriate to the conditions and what the fixed numerical speed limits dictate can be wildly different. For example, the default speed limit in the UK on most residential roads is 30mph, but if you drive past a school at 30mph at the end of the afternoon when the kids are coming out and there are lots parked cars obscuring your view, that is still inappropriately fast for the conditions. However, slower isn't always safer. On a motorway, the speed limit is usually 70mph, but in poor weather conditions and heavy traffic, everyone travelling at lower and similar speeds may be the safest choice. If you're the one driver insisting on unnecessarily doing 20mph when everyone else is doing a steady 40mph, you're also increasing the danger to yourself and others. Another example is that the speed limit for heavy goods vehicles on many of our major roads was increased by 10mph in 2015, having previously been 20mph below what cars were allowed to do on the same roads. The results were notable for several reasons, among them that the actual average speed of those heavy vehicles only increased a little but the safety of the roads appears to have increased. This was attributed primarily to closing the gap in speeds between different types of vehicle and thus, among other things, reducing instances of queues behind and overtaking of the slower vehicles, both of which increase the risk of an accident. Finally, we have the classic motorway speeding situation, where on an open road in good conditions, a competent driver with a suitable vehicle could do far more than the legal limit of 70mph with negligible increase in risk. Moreover, statistically our motorways are both our fastest roads and yet also among our safest. You could certainly print money by setting up a covert speed camera watching some stretches of motorway, but whether it is a good use of police resources if your objective is to increase road safety is a different question.
CraigJPerry 6y ago
>> results in accidents that are made much worse by excessive speed Sure but there's no free lunch here. If you trade off speed in the non-accident cases, which is by far the majority of all miles driven, then there's a cost to that. It happens to be a really hard to measure cost so it's always completely ignored. How would you even begin to measure the cost to the nation of traffic arriving 5 minutes later? Not all 5 minute delays are equal, e.g the cost of delay to an ambulance rushing to hospital is different to the increased cost of delivering packages. >> the reaction time available In fairness, you could make the reaction time measurable in hours and it'd be insufficient to prevent some inattention caused road incidents. Another problem with only looking at speed is the unintended consequence of drivers de-rating the risks. E.g. if a vehicle was limited to 5mph, this as you know is slow enough to be fairly unlikely to cause a pedestrian death even if there is an impact, it would have the un-wanted effect that some drivers would view the risks as lower and would be inclined to engage in more risky behaviours, e.g. taking their eyes off the road to turn around and argue with a child in the back seat where in 20mph traffic they might choose instead to just speak to the child. >> So the overall probability of accidents No that doesn't hold. We don't have more accidents on the fastest roads in the UK.
- yholio 6y ago
  > the cost to the nation of traffic arriving 5 minutes later? Traffic delays are dominated by congestion and road capacity does not increase with higher speeds. Once you hit the peak for that road section, trafic grinds. If, for example, you have a 30 minute comute that spends 15 minutes in congestion-limited trafic and 15 minutes on a speed limited empty highway, you would need to drive 50% faster on those sections to recoup a full 5 minutes, so something like 105 mph on a 70 mph section for a full 10 minutes. That doesn't sound realistic. There is a cost to low speed limits, clearly, but it is usually marginal - and when it's not, you should address that specific problem of a too low speed limit instead of making speed limits unenforceable throughout. If a section generates lots of speed tickets and no even minor incidents, it's clearly a sign to increase speed. > drivers de-rating the risks. True, but the risk rating they assigned to higher speeds was probably not proportional to the actual exponential increase to begin with. > We don't have more accidents on the fastest roads in the UK. That's moving the goal posts. The increase in risk is exponential on any given single road. Some roads are exceptionally safe at low speeds so you can increase the speed quite a bit and keep the risks low, hence the higher limits.

Shivetya 6y ago

It has not been all that long that we had technologies we could put into cars to determine if a driver was paying attention; though exactly what that is is also subject to interpretation With my Tesla I am able to have it chime if I exceed the speed limit by a set amount and even if a light turns green. however the big danger is still cell phone usage and no one wants to take the step of disabling them while moving and the technology is there.

CraigJPerry 6y ago
>> however the big danger is still cell phone usage There’s more than just cell phone usage. Inattention comes in many forms and none of them is better or worse than the others. Drivers paying more attention to the radio show they’re listening to while gently zoning out to the traffic conditions around them - this is really common on long motorway journeys. Drivers fizzing with rage at the argument they just had before getting in the car. Etc etc

lmm 6y ago

> And yet... road deaths are down over the same 20 years and mobility is up. > Road traffic enforcement isn’t even in the top 1000 issues facing the UK today. Road collisions are one of the biggest killers of young people in the UK. It's absolutely a big issue.

CraigJPerry 6y ago
What’s the bigger issue: road traffic enforcement or avoiding pedestrian deaths by finding acceptable ways to remove vehicles altogether from pedestrian areas? Road traffic enforcement or reducing infant asthma in cities by moving tailpipe emissions away from populated areas? Road traffic enforcement or ... you get the point.
- lmm 6y ago
  If we're not able to enforce existing rules then it's hard to see how introducing new rules could ever help anything.
  - CraigJPerry 6y ago
    Who’s suggesting adding new rules?
    - lmm 6y ago
      Well what are you suggesting then? I think enforcing the traffic laws we have is one of the low-hanging fruit for cutting the huge rate of deaths from traffic collisions. Are you proposing something concrete that would be better to spend our time on, or just finding an excuse to do nothing?
      - CraigJPerry 6y ago
        Every death should be avoided which should go without saying but this is the internet... >> huge rate We don't have huge rates compared to other countries - we're usually in the top 3 major developed countries every year for almost a decade at this point. We also don't have huge rates compared to other causes, e.g. there are under 2,000 road deaths each year but suicides top 6,500 per year. >> Are you proposing something concrete that would be better to spend our time on Yes - the solution for 0 road deaths does not exist purely in speed. Further, focussing only on speed has detrimental cost to the country. It's impossible to measure this cost so people ignore it. It is not sound methodology to ignore something simply because it can't be measured. As i stated upfront, enforcement of inappropriate speed should not be stopped, however, the biggest cause of road fatalaties - inattention - should now become a priority for enforcement. There is no technical gizmo available today for this therefore this means simply investing in more traffic police. No more complicated than that. I would expect though that some budget diverted from speed enforcement (which is a cost activity to the country despite the revenue it generates) would also be directed to figuring out more efficient ways of enforcing inattention. As i also said up front - this doesn't have to be in penalties, it might be better invested in making it less likely for drivers to be inattentive.