Cars kill pedestrians. The faster they go, the higher the risk of death or serious injury for Vulnerable Road Users (VRUs). The larger they are, the higher the risk of death, too. But above speeds...
Cars kill pedestrians. The faster they go, the higher the risk of death or serious injury for Vulnerable Road Users (VRUs). The larger they are, the higher the risk of death, too. But above speeds of 20 mph, the likelihood of pedestrian death in a collision caused by an automobile becomes noticeably high. Above 35 mph, it's more than 50%. Above 40 mph, pedestrians are almost certain to die when hit by a car.
Amsterdam decided to prioritize pedestrian safety over automobile throughput. That's better for our cities and better for our lives. American and European traffic engineers' ridiculous insistence on high levels of service (for cars) on local streets at the expense of pedestrian safety leads to completely avoidable death. Nowhere in the world should cars be permitted to travel above 20 mph in areas with lots of pedestrians, or on local streets where children might even conceivably be playing.
The maximum driving speed of majority of the Dutch capital’s roads will drop to 30 kilometers (less than 19 miles) per hour, down from the current 50kph from Friday. Amsterdam joins a growing crop of European cities who are instituting new efforts to improve road safety.
The multi-month effort to transition to new speeds stems from conversations with Amsterdam residents that found two-thirds say the traffic in their neighborhood is unsafe, the municipality said in a statement. While an average of more than three serious accidents takes place per day in the city, the new speed limit may reduce such incidents by as much as 30%, it said.
The municipality argues the lower speed limit will halve traffic noise and allow drivers to have more time to process information and respond to unexpected situations.
And it doesn't even ultimately affect travel times very much, because cities are full of traffic lights and other stopping points anyway. In other words, being able to drive at above 20 mph is completely pointless in a city because you're just going to get stuck a few hundred feet ahead.
Amsterdam follows cities such as Brussels, Paris and Madrid who have slashed road speeds in recent years. The municipality said it will readjust traffic lights for better traffic flow, while noting that motorists in Brussels haven’t experienced longer travel time since a rollout there in 2021.
It doesn't affect travel times because you're stuck in traffic anyway! In seriousness, all in all not a bad change and from what I can see, applied meaningfully and thoughtfully. Roads that should...
It doesn't affect travel times because you're stuck in traffic anyway!
In seriousness, all in all not a bad change and from what I can see, applied meaningfully and thoughtfully. Roads that should be faster are, and roads that should be slower will be (it starts tomorrow).
Here in San Francisco we’ve tried many things, including lowering speed limits and keeping many of the slow streets that were set up during the pandemic. But ultimately the most effective ways to...
Here in San Francisco we’ve tried many things, including lowering speed limits and keeping many of the slow streets that were set up during the pandemic. But ultimately the most effective ways to slow the traffic down are actual physical obstacles like speed bumps and bollards.
Firemen and ambulances hate them for safety and accessibility reasons but I think these problems can be solved. Speed limits and policy changes depend on an honor system that is broken. Take the choice away from people and force them to slow down or wreck their vehicle.
We also take driving education much too casually here in the US compared to most other countries. The barriers to getting a license are so little because we've forced the car to be the default...
We also take driving education much too casually here in the US compared to most other countries. The barriers to getting a license are so little because we've forced the car to be the default transportation option. I remember my driving lessons as a teen and it was all just in perfect Bay Area weather and on local roads. Never had lessons in inclement weather and only went on the highway for like 5 minutes and as I went down one exit in the slow lane.
I love my car and driving (on a good mountain road, not my local streets) but the majority of people are not fit to drive. The various activities that I've seen people doing while driving would be so much easier for them if they didn't have to pilot a 3-4k lb behemoth. Within the last week I've seen people reading a paper-back novel, drinking coffee from a porcelain mug, and eating burgers all while driving at 50+ mph. It's absolute lunacy.
When I lived in Amsterdam versus living now in San Francisco, one thing that is noticeable is ubiquitous traffic and parking enforcement. For example, you'll see these cars everywhere in...
When I lived in Amsterdam versus living now in San Francisco, one thing that is noticeable is ubiquitous traffic and parking enforcement.
For example, you'll see these cars everywhere in Amsterdam, combing major throughways and residential streets alike. The car automatically scans license plates and checks it against the National Parking Register and flags cars in violation.
There are also many politie and handhaving that patrol and run checkpoints, and a great deal of civil surveillance infrastructure.
It's quite hard to get away with bad driving and parking in Amsterdam when there is certainty and swiftness in enforcement, whereas in San Francisco I find it very permissive.
Wow, I would love it if my city bought cars like that. We've just recently gotten a little bit of automated ticketing in place for bus lanes, but nothing more comprehensive about parking in general.
Wow, I would love it if my city bought cars like that. We've just recently gotten a little bit of automated ticketing in place for bus lanes, but nothing more comprehensive about parking in general.
I agree that signage by itself is insufficient unless cars start getting active speed limiters in them. It certainly helps, but narrowing roads and installing traffic calming measures is more...
I agree that signage by itself is insufficient unless cars start getting active speed limiters in them. It certainly helps, but narrowing roads and installing traffic calming measures is more important.
But ultimately the most effective ways to slow the traffic down anre actual physical obstacles like speed bumps and bollards. Firemen and ambulances hate them for safety and accessibility reasons but I think these problems can be solved.
Bollards can be a great tool. It's also completely possible to set up active-signaled bollards that lower into the ground when an emergency vehicle needs to go past. These are more common in Europe and relatively rare in the US. In many cities you will literally get laughed at if you propose implementing them (as someone did in a meeting I attended on Monday), but I don't think that response is professional or constructive.
This is only sort of related, but there has been some quiet discussion in urbanist circles about the gradually increasing width of firetrucks in recent decades. I say "quiet" because no one wants to publicly criticize fire departments, which have an obviously important role in obviously dangerous situations (well, even though most calls they handle are extremely mundane... but a few are not!). But the need for very wide lanes on every single street is a bit of a problem as far as traffic calming is concerned, because wider lanes increase real-world driver speeds, thus increasing pedestrian fatalities. The prevailing ideology in many cities, which even progressive city planners unquestionably obey, is that every single street must have at least one 11-foot lane to accommodate massive firetrucks. Newer research suggests that that probably isn't necessary (10 feet at the most is usually sufficient, and meaningfully reduces speeds of other drivers, which also saves lives), both because firetrucks can typically fit in a 10-foot lane and because the firetrucks themselves don't necessarily have to be as wide as they currently are. As with other vehicle classes, they have also become bigger over time. The latter point is not something that can be solved immediately, but it is an observation that some people have made.
This is a basically completely un-studied area of urban planning because, as stated, who wants to pick a fight with the fire department? But it would be valuable for city planners and urban safety advocates to engage constructively with departments to find ways to manage traffic-calmed roadways more effectively and potentially start using slightly smaller vehicles.
My "hot take," which—while controversial with laypeople (as I've learned)—is, I speculate, probably quantitatively accurate, is that the relatively minor costs to travel time incurred by emergency vehicles as a result of speed bumps, bollards, and narrow lanes on neighborhood streets has a far smaller absolute value than the major negative costs incurred by having no traffic calming measures on those streets. Intuitively, if you think about how many cars speed down such streets every day, and how many thousands of people are killed every day as a result of not having traffic calming measures; and then think about how many firetrucks speed down those same streets every day, and think about how many people for whom a five-second slowdown on the part of a rescuer would be literally life-or-death... I am fairly confident that more people already regularly die because of a lack of traffic calming than would theoretically die in the edge cases where emergency vehicle access is slightly reduced as a side effect of traffic calming. (This is not to mention cases of emergency vehicles killing pedestrians, which also happens not infrequently.) That's not a scientific claim, and I don't know of any empirical analysis which specifically asks this question (because, again, no researcher wants to frame traffic calming as even marginally damaging to emergency vehicle operations), but it is my tentative belief at this time.
As the article I linked talks about, there are lots of situations where a behemoth of a firetruck is probably not as safe or useful as we assume it to be; and thus that having more "all purpose response" vehicles (the size of a typical pickup truck) is potentially a more holistically useful acquisition. And probably a lot cheaper. This is a case where thinking critically about why we've designed something the way it is currently designed is particularly valuable.
I'm not questioning this lower speed limit. It will reduce accidents and injuries and deaths, but... I don't know how it is where you live, but around me everyone gets driving licence, no matter...
I'm not questioning this lower speed limit. It will reduce accidents and injuries and deaths, but...
I don't know how it is where you live, but around me everyone gets driving licence, no matter if that person is actually capable driving on public roads in between other traffic. Also many people drive like self-centered unscrupulous reckless maniacs.
I'd say many accidents hapoen because of drivers not controlling themselves or their cars. This is what should be taken into consideration, too. Speed limit won't actually limit the speed that car and/or driver are capable of...
This isn't really true—a significant number of people do pay attention to posted speed limits when they're very visible, and many newer cars now bother you if you exceed speed limits—but you are...
Speed limit won't actually limit the speed that car and/or driver are capable of...
This isn't really true—a significant number of people do pay attention to posted speed limits when they're very visible, and many newer cars now bother you if you exceed speed limits—but you are right that reducing speed limits by themselves is an incomplete solution. @EarlyWords talked a bit about traffic calming measures like speed humps and bollards, which I think are also useful tools. I personally think that decreasing lane widths and overall making streets feel more enclosed is probably the most important infrastructure change.
The greatest strength of a speed limit is that it allows offending drivers to be ticketed for breaking the law. If a city bothers to have good enforcement procedures for automobile speeding (such as automated speed cameras, or just a good patrol force), the speed limit is pretty much the sole authority enabling them to issue tickets. It's harder for them to justify "erratic driving" (very subjective) than "you were going 35 in a 25."
You are right. But you are talking about drivers who take care of their driving and surroindings. While I was taking about people who care only about themselves ("I was speeding because I have to...
You are right. But you are talking about drivers who take care of their driving and surroindings.
While I was taking about people who care only about themselves ("I was speeding because I have to attend a meeting" or "If I crash I won't get harmed in my SUV" etc.). They will hapilly pay a fine which is too low for them (like 50-100€) or get their driving licence taken away (because, you know, cars don't require the person behind the wheel to have a licence).
There needs to be good system behind it. System that won't allow not-good-enoufh drivers to finish driving school, system that can prosecute those who don't care about it (ie. people repeatedly speeding, driving eithout licence etc.).
Here in Czech Republic such system doesn't actually exist. You an get driving permit even if you had to repeat driving school twenty times. You never attended driving school and police catches you behind the wheel? No worries, you can drive again the very same day - they will bepissed about it but what they can actually do? The most they can do is take away your car and/or send you before the judge, but you won't probably go to prison (on the first such trial). That means you may be able to drive without permit for even 10 years before it gets to that point. And be speeding along the way not paying attention to anything but yourself.
Well, sorry for that essay :-) Every system has some mistakes. Speed limits by itself won't work wonders but definitely help. Next step should be questioning why accidents still happen when limits were lowered.
I wondered what the benefits in reducing noise and pollution were. Because anecdotally the noise difference with speeds below 50 kph is not that big and as for emissions, cars get less efficient...
I wondered what the benefits in reducing noise and pollution were. Because anecdotally the noise difference with speeds below 50 kph is not that big and as for emissions, cars get less efficient at lower speeds, so I had no idea whether the effect of exerting less power or reducing efficiency would win out. So I googled some studies that did measurements.
Regarding noise, the reduction seems to be 1 - 5 dB. 5 dB is relatively significant (dB scale is exponential and we normally perceive 10 dB as doubling/halving loudness), 1 dB is just barely perceptible for most people. The areas with heaviest traffic (and most noise) were the ones with the smallest benefit. "Halving traffic noise", which is what Amsterdam claims, doesn't seem to be true.
In other words, effect was about the same as paving with special "silent asphalt", but that solution is of course significantly more expensive unless the road already needs paving (then it's still more expensive, but not by that much). It is, of course, possible to do both - though the effects do not add up linearly, silent asphalt has the biggest effect in higher speeds, and reducing speed works better on normal asphalt than on silent asphalt.
The average effect was bigger at night, so it might make sense to have extra speed limits from 10pm to 6am in places where noise is the main issue - this exists in some places in Prague for example.
Regarding emissions, there seems to be pretty much no difference. Some measurements got moderately worse, some got moderately better, it was slightly different for diesel and petrol cars, but overall there seems to be pretty much no reason to reduce speed when emissions are the motivation.
Regarding safety, this are just my thoughts, not studies: reducing speed in areas with a lot of pedestrians and/or kids seems like an obvious and sensible thing to do. But, anecdotally, this is already done in many places where I live - cities in Czechia. It's relatively common for narrow purely residential streets to have 30 kph limits, and it's standard in front of schools (sometimes time-limited during school time).
In Prague and Brno, the claim that there is no reason to go over 30 kph because of traffic lights etc. stopping traffic anyway is definitely not correct. There are many roads designed for high throughput where this is very obviously not the case. Some of them have no pedestrian access at all, some have wide sidewalks divided by a strip of grass etc. Then there are many streets where the situation is kind of in between these and obviously residential pedestrian heavy streets, where the limit is generally also 50 kph.
I have to wonder how much the statistics regarding accidents are distorted by the US where the pedestrian infrastructure is often simply worse and less safe than in many European cities ("stroads" for example don't exist here). The Amsterdam website doesn't seem to cite its sources for the 30% claim, so it's difficult to tell.
It seems obvious that slowing down traffic would reduce fatalities and bad injuries, but it would be a good idea to have good local enough statistics that take into account pedestrian infrastructure, possibly different behavior of local citizens etc. And also find out what the acceptable number of accidents with injuries or fatalities is, because the best way to reduce that dramatically would be to ban transportation (including public transport) altogether, which is obviously not sensible. So there's a legitimate discussion about where the sensible point of regulation is.
They absolutely do. Pedestrian infrastructure is much worse in the US, but there are absolutely stroads in Europe. I live in the middle of Berlin almost next to a six-lane road that is on the...
where the pedestrian infrastructure is often simply worse and less safe than in many European cities ("stroads" for example don't exist here)
They absolutely do. Pedestrian infrastructure is much worse in the US, but there are absolutely stroads in Europe. I live in the middle of Berlin almost next to a six-lane road that is on the borderline to being a stroad with a speed limit of 50 kph (which is regularly exceeded by the drivers on it). It's not even the worst such road in my borough of Berlin -- nearby there's another couple eight-lane roads running more or less parallel to it. While the pedestrian (and bicycle) infrastructure here is significantly better than on your prototypical US stroad, and the buildings along it are built mostly at a scale for pedestrians rather than cars (with several frustrating exceptions), many of the downsides of US stroads are still present. It's got the same problem of trying to be both a road and a street, and it's absolutely more dangerous because of it. As for noise, suffice it to say that there is an extremely noticeable difference between living alongside a road with a 50 kph speed limit and one with a 30 kph, even when people regularly speed on both.
And this is in the heart of a major European capital. Outside of such dense urban areas, there are absolutely roads that are even stroad-ier in at least central/northern Europe when you leave these urban centers.
It's difficult to assess this from a distance of course. I'll just add that throughput remains an important factor. Where there's fewer or no pedestrians, the speed limit is not lowered. It's the...
It's difficult to assess this from a distance of course. I'll just add that throughput remains an important factor. Where there's fewer or no pedestrians, the speed limit is not lowered. It's the inner city and specific pedestrian heavy areas that have their speeds reduced. It already was 30 in most streets, as that's the defined national maximum in residential streets, but now they added certain pedestrian-heavy-but-not-residential streets and roads.
I would love to read a follow up study after the new regulations have been in place for a while. In Madrid, new regulations saw a reduction in pollution of ~40%.
Regarding emissions, there seems to be pretty much no difference
You probably did this on accident, but this is what your comment reads like to me within the context of this topic: But what the article actually says is: It does not talk about regulating speed...
You probably did this on accident, but this is what your comment reads like to me within the context of this topic:
New regulations [on city speed limits?] reduced pollution by 40%
But what the article actually says is:
New regulations that ban older cars which pollute more than modern cars from entering parts of the city aim to reduce emissions by up to 40%.
It does not talk about regulating speed or about what the real reduction in emissions was.
Ah, sorry, I was using it as a catch all for emission/pollution reductions. My hope in sharing was to highlight that the validity of these schemes are often questioned but there have been some...
Ah, sorry, I was using it as a catch all for emission/pollution reductions. My hope in sharing was to highlight that the validity of these schemes are often questioned but there have been some real tangible benefits. But your new link does call that into question.
I didn't know it was struck down, I lived there in 2017 just as it was starting to roll out and was pretty excited by it. I'm a little fringey when it comes to these concepts as I think we know how to design in human centric ways and how to build for community benefit but road infrastructure and car access often stop meaningful change. Efforts like what is happening in Amsterdam - be it in a very progressive city already - give me hope that positive data points will come out of the measures that can be used to adopt those practices more widely.
I wasn't aware of the historical ups and downs, but I passed through recently and there very much is an active low-emissions zone (zona de bajas emisiones, ZBE). It's detailed here. Edit: I messed...
I wasn't aware of the historical ups and downs, but I passed through recently and there very much is an active low-emissions zone (zona de bajas emisiones, ZBE). It's detailed here.
Sokolovská and Vítězné náměstí area are extremely inconvenient stroads for both pedestrians and drivers. Too wide to easily cross, too many crossings for efficient traffic flow. Just a couple of...
Sokolovská and Vítězné náměstí area are extremely inconvenient stroads for both pedestrians and drivers. Too wide to easily cross, too many crossings for efficient traffic flow. Just a couple of examples from Prague.
Personally I definitely would not call Sokolovská extremely inconvenient as a pedestrian. Vítězné náměstí is kind of stupid and ugly on top, that's true. But in general I don't really feel that...
Personally I definitely would not call Sokolovská extremely inconvenient as a pedestrian. Vítězné náměstí is kind of stupid and ugly on top, that's true. But in general I don't really feel that Prague is inconvenient to pedestrians with any regularity, the one obvious exception being Severojižní magistrála.
Conspiracy theory time and something I've been pondering on since Wales and London introduced 20mph practically everywhere making travel ridiculously slow. They're prepping people for...
Conspiracy theory time and something I've been pondering on since Wales and London introduced 20mph practically everywhere making travel ridiculously slow.
They're prepping people for AI/Self-drive vehicles. If vehicles travel slower the likelihood of being killed is greatly reduced. If everyone is used to 20mph, when self driving vehicles are out on the roads they'll already feel accustomed to the speed and will be fine about it. Being hit at 20mph by any vehicle, whether by a human driven or AI car, you're more likely to survive. No corporate wants to have multiple death cases on their hands from AI murder death traps so starting off slow makes a lot of sense. As tech moves on and learning data improves, speeds will increase again.
I haven't read this anywhere, this is truly my own thoughts on the other reasons for bringing down the limits. Unfortunately many humans do not like the rules and you'll find anywhere there are no cameras, speed limits will be ignored.
My city enacted a 30km/h limit for most streets back in 2010, it's just a safety measure because humans also hit pedestrians and cyclists. Looking at the stats for the 1991-2021 period the number...
My city enacted a 30km/h limit for most streets back in 2010, it's just a safety measure because humans also hit pedestrians and cyclists.
Looking at the stats for the 1991-2021 period the number of accidents didn't really change but the deaths went down dramatically.
I see the AI connection but this kind of thing is pretty much exclusively for safety in the present. City planners are aware of the changes that autonomous vehicles would bring to the...
I see the AI connection but this kind of thing is pretty much exclusively for safety in the present. City planners are aware of the changes that autonomous vehicles would bring to the transportation system, but because these changes are extremely undefined, planners aren't making decisions on them yet.
As tech moves on and learning data improves, speeds will increase again.
This is an assumption I'm not super comfortable making. I don't think that autonomous vehicles will necessarily ever have the omnipotence to be able to barrel down a complex local street at 40+ mph without still killing people. That implies a level of predictive skill beyond physical sight lines; that is, the understanding of context that would lead a human driver to be more cautious in a particular area without explicitly being told to do so, or without having an explicit environmental cue to do so.
For example, understanding invisible desire paths that pedestrians would take between parked cars, perhaps to avoid (largely invisible to a car) sidewalk construction, something that a local would know from experience but that would unquestionably surprise an AI driver. Or knowing that since there's an unusual sports game featuring non-locals unfamiliar with the streetscape, both drunkenness and general confused/erratic behavior from pedestrians is going to change the parameters the machine needs to be taking to make correct decisions. I'm sure that you could train an AI very narrowly to solve many such problems, but the problem is specifically generalizing it. Until we have an AI that understands the human condition semantically rather than analyzing it statistically, I'm not keen on giving the machines a blank check to do whatever they like.
And unless driving a car as a human being is literally banned in favor of AI-only driving (which, somehow, I doubt would ever happen even in the UK), the risk of death caused by human drivers is still present. For that reason alone, streets still have to be designed for lower speeds.
I just don't think anyone should be driving any vehicle of any sort on at-grade streets that goes more than 20 or 25 mph. That includes human-driven cars, autonomous cars, and even light rail if it isn't grade-separated. I just don't see the value in minimally increasing vehicle throughput on what should be complete streets at the cost of human life. Not to mention that fast cars are largely unavoidably loud and irritating due to tire friction... I'd rather have a quieter streetscape too.
Yeah, self-driving AI cars will one day reach a point (probably sooner than we think) where they are able to drive much faster, much safer than humans. Better sensors, better response times,...
As tech moves on and learning data improves, speeds will increase again.
Yeah, self-driving AI cars will one day reach a point (probably sooner than we think) where they are able to drive much faster, much safer than humans. Better sensors, better response times, collaborative data from other AI cars in the area, etc.
I don't doubt you that this time will come. It's essentially inevitable if the climate doesn't get us first. That said, we're talking ideal conditions in these cases. The cars will obviously work...
where they are able to drive much faster, much safer than humans.
I don't doubt you that this time will come. It's essentially inevitable if the climate doesn't get us first.
That said, we're talking ideal conditions in these cases. The cars will obviously work better in ideal conditions because they're not prone to distraction like human drivers. I want to see better, faster, and safer in the worst conditions. Show me an AI that can effectively navigate a whited out road during a blizzard. Show me one that can manage torrential downpours or a washed out road.
Then again, in those conditions humans get worse as well - Nana with her four ways on going 10kph on the expressway due to a little rain. So, maybe I'm expecting AI to lap Louis Hamilton when I should be looking for it to out drive John Citizen instead.
Cars kill pedestrians. The faster they go, the higher the risk of death or serious injury for Vulnerable Road Users (VRUs). The larger they are, the higher the risk of death, too. But above speeds of 20 mph, the likelihood of pedestrian death in a collision caused by an automobile becomes noticeably high. Above 35 mph, it's more than 50%. Above 40 mph, pedestrians are almost certain to die when hit by a car.
Amsterdam decided to prioritize pedestrian safety over automobile throughput. That's better for our cities and better for our lives. American and European traffic engineers' ridiculous insistence on high levels of service (for cars) on local streets at the expense of pedestrian safety leads to completely avoidable death. Nowhere in the world should cars be permitted to travel above 20 mph in areas with lots of pedestrians, or on local streets where children might even conceivably be playing.
There are other major benefits, too, like noise reductions. There have been plenty of studies about the negative health consequences of urban noise, so decreasing it is a benefit:
And it doesn't even ultimately affect travel times very much, because cities are full of traffic lights and other stopping points anyway. In other words, being able to drive at above 20 mph is completely pointless in a city because you're just going to get stuck a few hundred feet ahead.
It doesn't affect travel times because you're stuck in traffic anyway!
In seriousness, all in all not a bad change and from what I can see, applied meaningfully and thoughtfully. Roads that should be faster are, and roads that should be slower will be (it starts tomorrow).
Here in San Francisco we’ve tried many things, including lowering speed limits and keeping many of the slow streets that were set up during the pandemic. But ultimately the most effective ways to slow the traffic down are actual physical obstacles like speed bumps and bollards.
Firemen and ambulances hate them for safety and accessibility reasons but I think these problems can be solved. Speed limits and policy changes depend on an honor system that is broken. Take the choice away from people and force them to slow down or wreck their vehicle.
We also take driving education much too casually here in the US compared to most other countries. The barriers to getting a license are so little because we've forced the car to be the default transportation option. I remember my driving lessons as a teen and it was all just in perfect Bay Area weather and on local roads. Never had lessons in inclement weather and only went on the highway for like 5 minutes and as I went down one exit in the slow lane.
I love my car and driving (on a good mountain road, not my local streets) but the majority of people are not fit to drive. The various activities that I've seen people doing while driving would be so much easier for them if they didn't have to pilot a 3-4k lb behemoth. Within the last week I've seen people reading a paper-back novel, drinking coffee from a porcelain mug, and eating burgers all while driving at 50+ mph. It's absolute lunacy.
When I lived in Amsterdam versus living now in San Francisco, one thing that is noticeable is ubiquitous traffic and parking enforcement.
For example, you'll see these cars everywhere in Amsterdam, combing major throughways and residential streets alike. The car automatically scans license plates and checks it against the National Parking Register and flags cars in violation.
There are also many politie and handhaving that patrol and run checkpoints, and a great deal of civil surveillance infrastructure.
It's quite hard to get away with bad driving and parking in Amsterdam when there is certainty and swiftness in enforcement, whereas in San Francisco I find it very permissive.
Wow, I would love it if my city bought cars like that. We've just recently gotten a little bit of automated ticketing in place for bus lanes, but nothing more comprehensive about parking in general.
I was under the impression that city buses in San Francisco had something similar.
I agree that signage by itself is insufficient unless cars start getting active speed limiters in them. It certainly helps, but narrowing roads and installing traffic calming measures is more important.
Bollards can be a great tool. It's also completely possible to set up active-signaled bollards that lower into the ground when an emergency vehicle needs to go past. These are more common in Europe and relatively rare in the US. In many cities you will literally get laughed at if you propose implementing them (as someone did in a meeting I attended on Monday), but I don't think that response is professional or constructive.
This is only sort of related, but there has been some quiet discussion in urbanist circles about the gradually increasing width of firetrucks in recent decades. I say "quiet" because no one wants to publicly criticize fire departments, which have an obviously important role in obviously dangerous situations (well, even though most calls they handle are extremely mundane... but a few are not!). But the need for very wide lanes on every single street is a bit of a problem as far as traffic calming is concerned, because wider lanes increase real-world driver speeds, thus increasing pedestrian fatalities. The prevailing ideology in many cities, which even progressive city planners unquestionably obey, is that every single street must have at least one 11-foot lane to accommodate massive firetrucks. Newer research suggests that that probably isn't necessary (10 feet at the most is usually sufficient, and meaningfully reduces speeds of other drivers, which also saves lives), both because firetrucks can typically fit in a 10-foot lane and because the firetrucks themselves don't necessarily have to be as wide as they currently are. As with other vehicle classes, they have also become bigger over time. The latter point is not something that can be solved immediately, but it is an observation that some people have made.
This is a basically completely un-studied area of urban planning because, as stated, who wants to pick a fight with the fire department? But it would be valuable for city planners and urban safety advocates to engage constructively with departments to find ways to manage traffic-calmed roadways more effectively and potentially start using slightly smaller vehicles.
My "hot take," which—while controversial with laypeople (as I've learned)—is, I speculate, probably quantitatively accurate, is that the relatively minor costs to travel time incurred by emergency vehicles as a result of speed bumps, bollards, and narrow lanes on neighborhood streets has a far smaller absolute value than the major negative costs incurred by having no traffic calming measures on those streets. Intuitively, if you think about how many cars speed down such streets every day, and how many thousands of people are killed every day as a result of not having traffic calming measures; and then think about how many firetrucks speed down those same streets every day, and think about how many people for whom a five-second slowdown on the part of a rescuer would be literally life-or-death... I am fairly confident that more people already regularly die because of a lack of traffic calming than would theoretically die in the edge cases where emergency vehicle access is slightly reduced as a side effect of traffic calming. (This is not to mention cases of emergency vehicles killing pedestrians, which also happens not infrequently.) That's not a scientific claim, and I don't know of any empirical analysis which specifically asks this question (because, again, no researcher wants to frame traffic calming as even marginally damaging to emergency vehicle operations), but it is my tentative belief at this time.
As the article I linked talks about, there are lots of situations where a behemoth of a firetruck is probably not as safe or useful as we assume it to be; and thus that having more "all purpose response" vehicles (the size of a typical pickup truck) is potentially a more holistically useful acquisition. And probably a lot cheaper. This is a case where thinking critically about why we've designed something the way it is currently designed is particularly valuable.
I'm not questioning this lower speed limit. It will reduce accidents and injuries and deaths, but...
I don't know how it is where you live, but around me everyone gets driving licence, no matter if that person is actually capable driving on public roads in between other traffic. Also many people drive like self-centered unscrupulous reckless maniacs.
I'd say many accidents hapoen because of drivers not controlling themselves or their cars. This is what should be taken into consideration, too. Speed limit won't actually limit the speed that car and/or driver are capable of...
This isn't really true—a significant number of people do pay attention to posted speed limits when they're very visible, and many newer cars now bother you if you exceed speed limits—but you are right that reducing speed limits by themselves is an incomplete solution. @EarlyWords talked a bit about traffic calming measures like speed humps and bollards, which I think are also useful tools. I personally think that decreasing lane widths and overall making streets feel more enclosed is probably the most important infrastructure change.
The greatest strength of a speed limit is that it allows offending drivers to be ticketed for breaking the law. If a city bothers to have good enforcement procedures for automobile speeding (such as automated speed cameras, or just a good patrol force), the speed limit is pretty much the sole authority enabling them to issue tickets. It's harder for them to justify "erratic driving" (very subjective) than "you were going 35 in a 25."
You are right. But you are talking about drivers who take care of their driving and surroindings.
While I was taking about people who care only about themselves ("I was speeding because I have to attend a meeting" or "If I crash I won't get harmed in my SUV" etc.). They will hapilly pay a fine which is too low for them (like 50-100€) or get their driving licence taken away (because, you know, cars don't require the person behind the wheel to have a licence).
There needs to be good system behind it. System that won't allow not-good-enoufh drivers to finish driving school, system that can prosecute those who don't care about it (ie. people repeatedly speeding, driving eithout licence etc.).
Here in Czech Republic such system doesn't actually exist. You an get driving permit even if you had to repeat driving school twenty times. You never attended driving school and police catches you behind the wheel? No worries, you can drive again the very same day - they will bepissed about it but what they can actually do? The most they can do is take away your car and/or send you before the judge, but you won't probably go to prison (on the first such trial). That means you may be able to drive without permit for even 10 years before it gets to that point. And be speeding along the way not paying attention to anything but yourself.
Well, sorry for that essay :-) Every system has some mistakes. Speed limits by itself won't work wonders but definitely help. Next step should be questioning why accidents still happen when limits were lowered.
I wondered what the benefits in reducing noise and pollution were. Because anecdotally the noise difference with speeds below 50 kph is not that big and as for emissions, cars get less efficient at lower speeds, so I had no idea whether the effect of exerting less power or reducing efficiency would win out. So I googled some studies that did measurements.
Regarding noise, the reduction seems to be 1 - 5 dB. 5 dB is relatively significant (dB scale is exponential and we normally perceive 10 dB as doubling/halving loudness), 1 dB is just barely perceptible for most people. The areas with heaviest traffic (and most noise) were the ones with the smallest benefit. "Halving traffic noise", which is what Amsterdam claims, doesn't seem to be true.
In other words, effect was about the same as paving with special "silent asphalt", but that solution is of course significantly more expensive unless the road already needs paving (then it's still more expensive, but not by that much). It is, of course, possible to do both - though the effects do not add up linearly, silent asphalt has the biggest effect in higher speeds, and reducing speed works better on normal asphalt than on silent asphalt.
The average effect was bigger at night, so it might make sense to have extra speed limits from 10pm to 6am in places where noise is the main issue - this exists in some places in Prague for example.
Regarding emissions, there seems to be pretty much no difference. Some measurements got moderately worse, some got moderately better, it was slightly different for diesel and petrol cars, but overall there seems to be pretty much no reason to reduce speed when emissions are the motivation.
Regarding safety, this are just my thoughts, not studies: reducing speed in areas with a lot of pedestrians and/or kids seems like an obvious and sensible thing to do. But, anecdotally, this is already done in many places where I live - cities in Czechia. It's relatively common for narrow purely residential streets to have 30 kph limits, and it's standard in front of schools (sometimes time-limited during school time).
In Prague and Brno, the claim that there is no reason to go over 30 kph because of traffic lights etc. stopping traffic anyway is definitely not correct. There are many roads designed for high throughput where this is very obviously not the case. Some of them have no pedestrian access at all, some have wide sidewalks divided by a strip of grass etc. Then there are many streets where the situation is kind of in between these and obviously residential pedestrian heavy streets, where the limit is generally also 50 kph.
I have to wonder how much the statistics regarding accidents are distorted by the US where the pedestrian infrastructure is often simply worse and less safe than in many European cities ("stroads" for example don't exist here). The Amsterdam website doesn't seem to cite its sources for the 30% claim, so it's difficult to tell.
It seems obvious that slowing down traffic would reduce fatalities and bad injuries, but it would be a good idea to have good local enough statistics that take into account pedestrian infrastructure, possibly different behavior of local citizens etc. And also find out what the acceptable number of accidents with injuries or fatalities is, because the best way to reduce that dramatically would be to ban transportation (including public transport) altogether, which is obviously not sensible. So there's a legitimate discussion about where the sensible point of regulation is.
They absolutely do. Pedestrian infrastructure is much worse in the US, but there are absolutely stroads in Europe. I live in the middle of Berlin almost next to a six-lane road that is on the borderline to being a stroad with a speed limit of 50 kph (which is regularly exceeded by the drivers on it). It's not even the worst such road in my borough of Berlin -- nearby there's another couple eight-lane roads running more or less parallel to it. While the pedestrian (and bicycle) infrastructure here is significantly better than on your prototypical US stroad, and the buildings along it are built mostly at a scale for pedestrians rather than cars (with several frustrating exceptions), many of the downsides of US stroads are still present. It's got the same problem of trying to be both a road and a street, and it's absolutely more dangerous because of it. As for noise, suffice it to say that there is an extremely noticeable difference between living alongside a road with a 50 kph speed limit and one with a 30 kph, even when people regularly speed on both.
And this is in the heart of a major European capital. Outside of such dense urban areas, there are absolutely roads that are even stroad-ier in at least central/northern Europe when you leave these urban centers.
It's difficult to assess this from a distance of course. I'll just add that throughput remains an important factor. Where there's fewer or no pedestrians, the speed limit is not lowered. It's the inner city and specific pedestrian heavy areas that have their speeds reduced. It already was 30 in most streets, as that's the defined national maximum in residential streets, but now they added certain pedestrian-heavy-but-not-residential streets and roads.
I would love to read a follow up study after the new regulations have been in place for a while. In Madrid, new regulations saw a reduction in pollution of ~40%.
You probably did this on accident, but this is what your comment reads like to me within the context of this topic:
But what the article actually says is:
It does not talk about regulating speed or about what the real reduction in emissions was.
edit: Interesting bit: proponents of this Madrid solution claim that it reduced emissions by 22%, but we will probably not find any better results as courts considered the implementation illegal and ordered a stop to it
Ah, sorry, I was using it as a catch all for emission/pollution reductions. My hope in sharing was to highlight that the validity of these schemes are often questioned but there have been some real tangible benefits. But your new link does call that into question.
I didn't know it was struck down, I lived there in 2017 just as it was starting to roll out and was pretty excited by it. I'm a little fringey when it comes to these concepts as I think we know how to design in human centric ways and how to build for community benefit but road infrastructure and car access often stop meaningful change. Efforts like what is happening in Amsterdam - be it in a very progressive city already - give me hope that positive data points will come out of the measures that can be used to adopt those practices more widely.
I wasn't aware of the historical ups and downs, but I passed through recently and there very much is an active low-emissions zone (zona de bajas emisiones, ZBE). It's detailed here.
Edit: I messed up the link formatting
Sokolovská and Vítězné náměstí area are extremely inconvenient stroads for both pedestrians and drivers. Too wide to easily cross, too many crossings for efficient traffic flow. Just a couple of examples from Prague.
Personally I definitely would not call Sokolovská extremely inconvenient as a pedestrian. Vítězné náměstí is kind of stupid and ugly on top, that's true. But in general I don't really feel that Prague is inconvenient to pedestrians with any regularity, the one obvious exception being Severojižní magistrála.
Conspiracy theory time and something I've been pondering on since Wales and London introduced 20mph practically everywhere making travel ridiculously slow.
They're prepping people for AI/Self-drive vehicles. If vehicles travel slower the likelihood of being killed is greatly reduced. If everyone is used to 20mph, when self driving vehicles are out on the roads they'll already feel accustomed to the speed and will be fine about it. Being hit at 20mph by any vehicle, whether by a human driven or AI car, you're more likely to survive. No corporate wants to have multiple death cases on their hands from AI murder death traps so starting off slow makes a lot of sense. As tech moves on and learning data improves, speeds will increase again.
I haven't read this anywhere, this is truly my own thoughts on the other reasons for bringing down the limits. Unfortunately many humans do not like the rules and you'll find anywhere there are no cameras, speed limits will be ignored.
My city enacted a 30km/h limit for most streets back in 2010, it's just a safety measure because humans also hit pedestrians and cyclists.
Looking at the stats for the 1991-2021 period the number of accidents didn't really change but the deaths went down dramatically.
I see the AI connection but this kind of thing is pretty much exclusively for safety in the present. City planners are aware of the changes that autonomous vehicles would bring to the transportation system, but because these changes are extremely undefined, planners aren't making decisions on them yet.
This is an assumption I'm not super comfortable making. I don't think that autonomous vehicles will necessarily ever have the omnipotence to be able to barrel down a complex local street at 40+ mph without still killing people. That implies a level of predictive skill beyond physical sight lines; that is, the understanding of context that would lead a human driver to be more cautious in a particular area without explicitly being told to do so, or without having an explicit environmental cue to do so.
For example, understanding invisible desire paths that pedestrians would take between parked cars, perhaps to avoid (largely invisible to a car) sidewalk construction, something that a local would know from experience but that would unquestionably surprise an AI driver. Or knowing that since there's an unusual sports game featuring non-locals unfamiliar with the streetscape, both drunkenness and general confused/erratic behavior from pedestrians is going to change the parameters the machine needs to be taking to make correct decisions. I'm sure that you could train an AI very narrowly to solve many such problems, but the problem is specifically generalizing it. Until we have an AI that understands the human condition semantically rather than analyzing it statistically, I'm not keen on giving the machines a blank check to do whatever they like.
And unless driving a car as a human being is literally banned in favor of AI-only driving (which, somehow, I doubt would ever happen even in the UK), the risk of death caused by human drivers is still present. For that reason alone, streets still have to be designed for lower speeds.
I just don't think anyone should be driving any vehicle of any sort on at-grade streets that goes more than 20 or 25 mph. That includes human-driven cars, autonomous cars, and even light rail if it isn't grade-separated. I just don't see the value in minimally increasing vehicle throughput on what should be complete streets at the cost of human life. Not to mention that fast cars are largely unavoidably loud and irritating due to tire friction... I'd rather have a quieter streetscape too.
Yeah, self-driving AI cars will one day reach a point (probably sooner than we think) where they are able to drive much faster, much safer than humans. Better sensors, better response times, collaborative data from other AI cars in the area, etc.
I don't doubt you that this time will come. It's essentially inevitable if the climate doesn't get us first.
That said, we're talking ideal conditions in these cases. The cars will obviously work better in ideal conditions because they're not prone to distraction like human drivers. I want to see better, faster, and safer in the worst conditions. Show me an AI that can effectively navigate a whited out road during a blizzard. Show me one that can manage torrential downpours or a washed out road.
Then again, in those conditions humans get worse as well - Nana with her four ways on going 10kph on the expressway due to a little rain. So, maybe I'm expecting AI to lap Louis Hamilton when I should be looking for it to out drive John Citizen instead.