Fun fact: The faster a car travels, the bigger the spacing between the cars gets. That’s necessary to leave enough distance for emergency stops.
While the speed increases linearly, the spacing increases with the square, meaning at double the speed, the spacing quadruples, which in turn means that throughput (number of cars per hour) halves.
This is the reason why many regions use electronic speed signs to drop the speedlimit lower when there’s congestion. Because it increases throughput and thus reduces travel times.
The optimum speed for high throughput is 30km/h.
Counterintuitive as it might be, drivers should be all for 30km/h speed limit in cities, because it would make them get to work faster.
You can cite an infinite amount of proven facts and studies, car brains will never accept your „communist propaganda“. This whole discussion is too emotionally loaded to be based on facts.
And there’s where we invent roundabouts. Even when the streets are not congested the time to cross any urban area is dominated by the stops. It much more beneficial to eliminate stop signs and red lights, to keep you moving consistently than to let you speed a little more to your next stopping point
Yep, and at that speed, 50km/h on an “empty” street INSIDE a city, that’s also the most “efficient” speed to avoid those pesky children bits getting stuck on your windchill were you to tackle one while checking your phone.
Apologies for the sarcasm but most drivers I encounter on a daily basis absolutely do not have the sustained concentration behind wheels to safely drive a 50km/h within actual cities.
If children are a factor (residential street, school zone, playground, etc) there’s all the reason to limit to 30, or even 20 (like the street I live where kids are playing around). Optionally time restricted.
Main avenues with clear sidewalks separated by a green strip can have 50 or even 60 km/h limits.
As an adult, relatively big (1m85) who doesn’t randomly run across a street but rather use solely clearly marked zebras I sadly have to report that I had numerous encounter with cars at a very uncomfortable distance to my body, some even touching me (not an accident proper though). I did have of course the occasional wave saying “Oops, sorry I didn’t see you or care for slowing down, moving on!”. When I say occasional it’s probably once a month or more.
To clarify this happened next to a park with very VERY good visibility, a straight line without trees, where it’s slightly higher speed than around. Namely small streets around the park are 20km/h, that avenue is 50km/h. It is actually such a problem a red light has been installed 200m further. I assume that enough cars refused to yield so that this change was made.
This makes me believe that unfortunately, even though MOST drivers are indeed able to safely drive in “Main avenues with clear sidewalks” there is still a non negligible amount from my experience as a pedestrian who absolutely can not and are a danger for everyone, kids and adults alike.
That being said, you have the right to believe that few accidents are acceptable if it allows most people to keep such a certain speed.
I sadly have to report that I had numerous encounter with cars at a very uncomfortable distance to my body
When I was younger and had worse impulse control, some fool in a sports car blasted through the zebra crossing I was in, missing me by less than a foot, only to stop a few feet from me because there was a stationary queue of traffic ahead of him (so why go through the zebra crossing at all?). So I kicked out one of his tail lights, kicked off his driver’s side wing mirror, and when he tried to get out of the car, repeatedly kicked the door shut on his ankle each time he’d try to open it. At some point, he realised I was not only much larger than him but also much crazier, and drove on (the queue had cleared by then). Ah, the days before there were ubiquitous cameras!
To clarify this happened next to a park with very VERY good visibility, a straight line without trees, where it’s slightly higher speed than around.
That’s not surprising to me (as an engineer); the dangerous encounters probably happened because the street was straight and had a generous clear zone.
Strong Towns “30 days of confessions” series has a couple of good (short! – under 2 minutes each) videos explaining it:
Of course it makes sense. In fact I believe I have a similar problem while cycling on a one way street for cars while cycling on the (non protected) bike lane of the opposite direction. I hate that street because very often cars do not move away… because they don’t look up. They are busy doing I don’t know what in their cars… probably because, if I understood the idea properly, they think it’s all fine, nobody “should” come from anywhere but behind them, so the “can” be “distracted”.
I’m an adult just slightly bigger and have never had an encounter like you describe, and I lived in a big city decades, using public transport and walking exclusively. If drivers in your environment are that bad, stricter limits are reasonable.
Yet I also see them and a lot more frequently since pandemic. I still claim everyone forgot how to drive safely.
For me the big problem is that it’s legal to “turn right on red”. However people for get that you’re supposed to come to a full stop and to yield to any road user. So many times I’m in the crosswalk with the walk signal lighted yet someone zooms through to take a right on red barely slowing and without concern for pedestrians
We also seem to have gotten a lot worse with “stretching a yellow”. Why is it that I can wait for a light to turn red, then wait a couple more seconds for the walk signal to come on, yet still be endangered by someone blasting through the intersection claiming “my light was yellow, bro”.
Or maybe it’s just the self-centeredness. People have so much trouble being aware that someone is travelling differently than they are. Pedestrians are invisible because “everyone drives”, cars zoom right up to and through crosswalks at a red light because “no one will be in the crosswalk”.
It’s become a running joke with my kids that you always have to look the wrong way before crossing the street. We regularly cross a one way street where we have twice had close calls with someone going the wrong way. Knowing the layout, I’m pretty sure it’s intentional. It would be difficult to do on accident and I can see the “short cut” being much more convenient
My guess North American (because of the turn right on red) and European car cultures are different. European cities are much more walkable and drivers are used to pedestrians. I rarely have a car not stop if I come up to a cross walk, and basically 100% if I’m with my kids.
Fun fact: The faster a car travels, the bigger the spacing between the cars gets. That’s necessary to leave enough distance for emergency stops.
While the speed increases linearly, the spacing increases with the square, meaning at double the speed, the spacing quadruples, which in turn means that throughput (number of cars per hour) halves.
This is the reason why many regions use electronic speed signs to drop the speedlimit lower when there’s congestion. Because it increases throughput and thus reduces travel times.
The optimum speed for high throughput is 30km/h.
Counterintuitive as it might be, drivers should be all for 30km/h speed limit in cities, because it would make them get to work faster.
That’s also the fastest speed before sharply increasing the likelihood of fatality in pedestrian collisions
You can cite an infinite amount of proven facts and studies, car brains will never accept your „communist propaganda“. This whole discussion is too emotionally loaded to be based on facts.
Another related fun fact: Larger vehicles are harder to see around, so people have to leave even more distance which reduces throughput.
The problem is that often streets are not congested, and then 50km/h is much more time efficient.
And there’s where we invent roundabouts. Even when the streets are not congested the time to cross any urban area is dominated by the stops. It much more beneficial to eliminate stop signs and red lights, to keep you moving consistently than to let you speed a little more to your next stopping point
Yeah, big thumbs up for roundabouts.
Yeah, unless you’re a pedestrian.
Why’s it a problem? I crossed them every day, cars usually drive quite slowly around them.
Yep, and at that speed, 50km/h on an “empty” street INSIDE a city, that’s also the most “efficient” speed to avoid those pesky children bits getting stuck on your windchill were you to tackle one while checking your phone.
Apologies for the sarcasm but most drivers I encounter on a daily basis absolutely do not have the sustained concentration behind wheels to safely drive a 50km/h within actual cities.
I have seen old people driving around with oxygen tubes in their noses more times than I feel is safe.
If children are a factor (residential street, school zone, playground, etc) there’s all the reason to limit to 30, or even 20 (like the street I live where kids are playing around). Optionally time restricted.
Main avenues with clear sidewalks separated by a green strip can have 50 or even 60 km/h limits.
As an adult, relatively big (1m85) who doesn’t randomly run across a street but rather use solely clearly marked zebras I sadly have to report that I had numerous encounter with cars at a very uncomfortable distance to my body, some even touching me (not an accident proper though). I did have of course the occasional wave saying “Oops, sorry I didn’t see you or care for slowing down, moving on!”. When I say occasional it’s probably once a month or more.
To clarify this happened next to a park with very VERY good visibility, a straight line without trees, where it’s slightly higher speed than around. Namely small streets around the park are 20km/h, that avenue is 50km/h. It is actually such a problem a red light has been installed 200m further. I assume that enough cars refused to yield so that this change was made.
This makes me believe that unfortunately, even though MOST drivers are indeed able to safely drive in “Main avenues with clear sidewalks” there is still a non negligible amount from my experience as a pedestrian who absolutely can not and are a danger for everyone, kids and adults alike.
That being said, you have the right to believe that few accidents are acceptable if it allows most people to keep such a certain speed.
When I was younger and had worse impulse control, some fool in a sports car blasted through the zebra crossing I was in, missing me by less than a foot, only to stop a few feet from me because there was a stationary queue of traffic ahead of him (so why go through the zebra crossing at all?). So I kicked out one of his tail lights, kicked off his driver’s side wing mirror, and when he tried to get out of the car, repeatedly kicked the door shut on his ankle each time he’d try to open it. At some point, he realised I was not only much larger than him but also much crazier, and drove on (the queue had cleared by then). Ah, the days before there were ubiquitous cameras!
That’s not surprising to me (as an engineer); the dangerous encounters probably happened because the street was straight and had a generous clear zone.
Strong Towns “30 days of confessions” series has a couple of good (short! – under 2 minutes each) videos explaining it:
https://www.youtube.com/watch?v=FHXiZ3wEzMY
https://www.youtube.com/watch?v=oGwe1Hf2Igg
Fascinating, thanks for sharing!
Of course it makes sense. In fact I believe I have a similar problem while cycling on a one way street for cars while cycling on the (non protected) bike lane of the opposite direction. I hate that street because very often cars do not move away… because they don’t look up. They are busy doing I don’t know what in their cars… probably because, if I understood the idea properly, they think it’s all fine, nobody “should” come from anywhere but behind them, so the “can” be “distracted”.
Also makes me think of Jevons’s paradox (or the rebound effect) but for attention or even more broadly cognition.
I’m an adult just slightly bigger and have never had an encounter like you describe, and I lived in a big city decades, using public transport and walking exclusively. If drivers in your environment are that bad, stricter limits are reasonable.
Yet I also see them and a lot more frequently since pandemic. I still claim everyone forgot how to drive safely.
For me the big problem is that it’s legal to “turn right on red”. However people for get that you’re supposed to come to a full stop and to yield to any road user. So many times I’m in the crosswalk with the walk signal lighted yet someone zooms through to take a right on red barely slowing and without concern for pedestrians
We also seem to have gotten a lot worse with “stretching a yellow”. Why is it that I can wait for a light to turn red, then wait a couple more seconds for the walk signal to come on, yet still be endangered by someone blasting through the intersection claiming “my light was yellow, bro”.
Or maybe it’s just the self-centeredness. People have so much trouble being aware that someone is travelling differently than they are. Pedestrians are invisible because “everyone drives”, cars zoom right up to and through crosswalks at a red light because “no one will be in the crosswalk”.
It’s become a running joke with my kids that you always have to look the wrong way before crossing the street. We regularly cross a one way street where we have twice had close calls with someone going the wrong way. Knowing the layout, I’m pretty sure it’s intentional. It would be difficult to do on accident and I can see the “short cut” being much more convenient
My guess North American (because of the turn right on red) and European car cultures are different. European cities are much more walkable and drivers are used to pedestrians. I rarely have a car not stop if I come up to a cross walk, and basically 100% if I’m with my kids.