this post was submitted on 18 Apr 2026
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Fuck Cars

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Those who use the bike know this very well: in the city, speeding motorists overtaking other cars, only get one thing: they arrive first to the next red.

With a simple model, the author estimated the probability that one car that overtakes another, will then be reached again at a later red light. Then he estimated the probability that the same thing will happen when there are multiple successive traffic lights, as usual in the cities.

The result is that as fast as an aggressive driver goes, the presence of multiple traffic lights makes it virtually certain that a slower driver will catch up

So, if someone aggressively overcomes you, when you reach him at the next traffic light, you can tell him that it is mathematically proven that he/she is an idiot.

In addition, this study has implications for the 30 km/h city, demonstrating how in urban areas the traffic lights determine the travel times, not the maximum speed reachable between one traffic light and the next.

The original scientific article is here: https://royalsocietypublishing.org/rsos/article/13/4/260310/481212/The-Voorhees-law-of-traffic-a-stochastic-model

crossposted from: https://poliversity.it/users/rivoluzioneurbanamobilita/statuses/116419204210303856

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[–] kunaltyagi@programming.dev 1 points 55 minutes ago

In theory, the practice and theory are the same and people actually arrive at the same time. In practice, people just jump the red light, climb onto the footpath, drive on the wrong side, etc. and beat the traffic time by 10-20 minutes

[–] kossa@feddit.org 5 points 10 hours ago* (last edited 10 hours ago)

Joke's on the math. In my city people who overtake dangerously also just go through a red light anyway. Idiots.

Edit: only once I witnessed the sweet sweet karma. Very smart person was going in the bus lane to overtake everybody else. But another very smart person just wanted to get into the bus lane as well to overtake everybody else. "Crash" (well, luckily only dented cars) followed, but I guess they were both late to their important destinations than everybody waiting in line.

[–] PapaStevesy@lemmy.world 5 points 15 hours ago (2 children)

This doesn't take into account the vast safety benefits of getting away from incompetent/inattentive drivers. I'm not necessarily passing you to "get there" faster, it's pretty easy to tell when a driver has no clue what they're doing and I don't want to have anything to do with that shit.

I actually have no clue if it doesn't take that into account, I didn't read the article, but you see what I'm saying.

I find I want the incompetent/inattentive drivers far off in front of me. Behind me I have a harder time keeping an eye on them along with everyone else. Far ahead, I have a better chance of reacting and correcting to their improper driving.

[–] Korhaka@sopuli.xyz 5 points 11 hours ago (1 children)

Just leave some distance with them in front of you, if they crash you have space to slow down before overtaking their burning wreck.

[–] PapaStevesy@lemmy.world 2 points 4 hours ago (1 children)

The options under discussion are pass and not be involved in a wreck or stay behind and wait to be involved in a wreck and somehow the second option is more appealing to you? Yeah no thanks, I'll pass and avoid it entirely instead of waiting for it to happen, hoping it happens in a predictable & easy-to-avoid way, hoping that every other driver on the road with us is also waiting for it to happen, hoping we all have perfect reaction time, hoping all our cars respond properly, and hoping that road conditions are "ideal." That's a lot of luck. If you can predict how and when a bad driver is gonna crash, you go ahead and caravan with them, I know I personally can't see the future so I'm going to get as far away as I possibly can.

[–] Korhaka@sopuli.xyz 1 points 2 hours ago (1 children)

Do you know how to drive behind another vehicle at a safe distance?

[–] PapaStevesy@lemmy.world 1 points 1 hour ago

Yes I was a mail carrier, I've driven professionally. Which means I also know how to most safely and efficiently get to my destination, and neither involve being at the whims of a dangerously negligent idiot going 30 mph slower than the flow of traffic. 🤷‍♂️

[–] AA5B@lemmy.world 14 points 1 day ago* (last edited 1 day ago)

This is where you get to properly reducing lanes can improve speeds.

My town has a major road lined with strip malls that used to be two lanes in each direction. It was also one of the most dangerous and aggravating roads as there was always someone maneuvering for position, and sudden stops or lane changes when someone wanted to turn.

Then a few years back they restriped it, plus coordinated the lights. Now it’s one lane in each direction and that lane is a through lane. Every strip mall gets a dedicated turn lane, so there’s no more reason to maneuver, no more sudden stops or lane changes. The stop lights are more likely to let you through.

Now it’s clear and measurable, everyone’s individual speed is down, accidents are down, but stopping for any reason is way down so you get through the busy section noticeable faster. And it’s much calmer

[–] UndergroundParking@lemmy.cafe 15 points 1 day ago

Till first light - yes. But then I won't get the penalty of you being slow or on your phone. You won't be behind me at the second light.

[–] brewery@feddit.uk 7 points 23 hours ago

I see this every week when I drive to the office. Most of the route is 20mph and single lane. I go at the speed limit and every 2/3 weeks one will overtake me. I'll then see them at the next light, then there next one, then the roundabout, etc for the next 30 minutes. I'll usually then go past them as theres one junction with 2 lanes and they always seem to go in the "fast" lane so they end up behind me when it goes down to one. Makes me so happy everytime!

Sometimes you see it when walking even in a black traffic spot - you'll get to the lights before the cars you've passed sitting there.

Im doing to build my fitness up to cycle the route and think it'll take roughly the same time.

Unfortunately the route is really difficult and long on public transport - it's easy to get into central and back but trying to go across the edge to the other side was never designed for

[–] Mongostein@lemmy.ca 40 points 1 day ago (1 children)

You’re also wasting gas accelerating to speeds that don’t get you anywhere any faster

[–] Almacca@aussie.zone 3 points 22 hours ago* (last edited 22 hours ago)

And wearing out your brakes faster by braking more heavily at the lights.

[–] MachineFab812@discuss.tchncs.de 5 points 22 hours ago* (last edited 16 hours ago)

Assuming that the traffic light changes colour based on a set time cycle rather than a sensor, and that the cars are travelling on a single-lane road, the results reveal that, taking into account the probabilities of each of the four scenarios, on average the possible gains and losses in spacing between the cars balance exactly.

... that's the opposite of most lights where I live. Even at midnight hours where many switch to timed-mode, there are many that won't change at-all unless a heavy-enough vehicle is in certain lanes, and even many cars get stuck having to exercise the rules about such that were meant for motorcycles and bicycles.

[–] Bubbaonthebeach@lemmy.ca 5 points 23 hours ago

Unless I am following a very heavy vehicle that takes a long time to get up to speed, I find there is almost no reason to pass the other traffic. Very seldom do the cars dashing around me get to the next light before it changes unless they are exceeding the speed limit by excessive amounts in which they are even more likely to cause a crash and still not beat me to the next light or other destination.

[–] driving_crooner@lemmy.eco.br 28 points 1 day ago (2 children)

This happens with me all the time in my e-bike, max speed is 40 or 50 in some roads, and I can go confortable at 30. They horn me, overpass me only to me to catch them on the next red and I pass them again

[–] FatVegan@leminal.space 11 points 1 day ago (1 children)

I don't even overtake ebikes with a number plate. What ist even the point. But people freak oyt behind.

[–] MachineFab812@discuss.tchncs.de 1 points 5 hours ago

What's the point in registering an "eBike" that can't keep-up with traffic? They're either lying that it can, or simply refusing to do so.

[–] MachineFab812@discuss.tchncs.de -4 points 22 hours ago (1 children)

You're the reason so many roads have a minimum-speed of 40mph. You're right that honking at you and trying to pass when there isn't PLENTY of room to do so is pointless, but only those two things, and I doubt the article is about your specific brand of non-sense.

[–] driving_crooner@lemmy.eco.br 4 points 15 hours ago (1 children)

Tell me how useful is a minimum speed if they're going to stop anyway on the next red light? If anything it shows how stupid is having speed limits higher of 30kmh in cities

[–] MachineFab812@discuss.tchncs.de 1 points 5 hours ago* (last edited 5 hours ago)

You realize light-timings are calibrated and coordinated based-on intended traffic speeds, right? Just because the speeders get stopped at the next light doesn't mean a too-slow driver doesn't get stopped by that same light after the speeder's got their green and gone-on.

Apparently you've never been on one of the roads I mentioned long-enough to notice they tend to have 4-lanes and lights spaced over a mile-apart, but even on a regular road with room to pass, demanding no-one do-so while you putter-along at just-over-half the speed-limit is asinine. Drivers can pass farm-equipment that takes up a lane-and-a-half, stopped emergency-vehicles/cops, mail-trucks, busses, street sweepers and dump-trucks, but not you?

So where's the part about what your asking in any-way-resembles sharing the road again? The article doesn't even mention bikes, golf-carts, or glorified mobility-scooters, btw.

Oh, and it literally says the opposite of what OP claims, even between motor-vehicles moving with normal traffic, not obstructing it:

That means, on average, the lead of one car over the other remains the same after the light as before.

The results suggest the idea the slower car will inevitably catch up at the lights is something of an illusion.

[–] IDew@lemmy.zip 21 points 1 day ago (1 children)

I always say to myself when someone impatiently overtakes me: "See you at the next red light!"

[–] SuiXi3D@fedia.io 7 points 1 day ago

For me it’s, “Wow, you sure did get to that light before everyone else. Good job!”

[–] HubertManne@piefed.social 6 points 1 day ago

I have experienced this. Someone with a distinctive enough car will get annoyed at my hypermiling and speed around. More often than not having to stop suddenly at the next light while I glide in but maybe they just make it. Later though I will be gliding in just as the green changes and they are there stopped while I just coast on through starting to accelerate as distance increases.

[–] Alcoholicorn@mander.xyz 16 points 1 day ago

When you filter at a red light on a motorcycle and the driver that was aggressively swerving all over the place yells about how dangerous and illegal it is.

[–] jtrek@startrek.website 7 points 1 day ago (1 children)

This matches my intuition. I extremely rarely do any city driving (I don't even own a car anymore) but like... You're not going to go that much faster. You're probably not driving very far. The total amount of time can't be that big.

[–] HubertManne@piefed.social 3 points 1 day ago

even on the highway I kinda looked at it like this. If I travel 1mph I can get there twice as fast at 2mph and on and on. so ou get to 64 and its like. ok so the next step is 128? no thank you. I mean its going to be depending on the measurments used but your still going to max out somewhere around there just due to how it works. Add in you are in energy efficient loss territory and its a no brainer.

[–] magnue@lemmy.world 11 points 1 day ago (1 children)

Yeah but what about when you leave the city and you just happen to pass that one car that wants to do 30 in a 60 on a straight road. Worth.

[–] mmcintyre@lemmy.world 3 points 1 day ago (1 children)

No red lights in the country. After you pass that slow car it ain't got no way of catching up to you.

[–] MML@sh.itjust.works 2 points 1 day ago

Oh but now you passed me!? I'm going to accelerate to 75! Driving in the US is awesome.

[–] sorter_plainview@lemmy.today 7 points 1 day ago* (last edited 1 day ago) (1 children)

My mental model is slightly different. I think of average speed of the car between source and destination. Every segment of the road will have an average speed at a given time, which may vary depending on the time of the day. This average speed is dictated by numerous factors, including traffic lights, number of slow vehicles on the road, speed limits, etc. You cannot really go significantly higher than this average speed, even if you try as aggressively as possible.

There are exception, especially in Asian roads. If you are a large vehicle, who doesn't care about the law and limits, and they do very aggressive driving, then they go at a larger average speed. I have some completely asshole private bus services in my country.

[–] GreyEyedGhost@piefed.ca 3 points 1 day ago

I find people who say this don't properly account for their time waiting at lights. Sure, you may be going faster when you aren't stopped, but you will catch those reds more often and will be stopped longer, reducing those average speeds. Which is the entire point of the article.

[–] atro_city@fedia.io 0 points 1 day ago (2 children)

No surprise there. I think people do it not to be faster but because they like the acceleration. That feeling of being pushed back into your seat pulling 0.1 Gs, man, it gets the small penis going!

[–] m4ylame0wecm@lemmy.zip 12 points 1 day ago

This occurs in un-penised motorists too.

[–] Martineski@lemmy.dbzer0.com 4 points 1 day ago (1 children)

Their behavior has nothing to do with their body and by body shaming people are just catching strays. Even if statistically they tended to have smaller penises it still wouldn't be cool just as it's not cool to be transphobic or racist just because you don't like the person. It's still transphobic or racist which is objectively bad. Just as is body shaming.

[–] atro_city@fedia.io -5 points 1 day ago

Man, social justice warriors really have to be offended about everything. Joke about body part? Body shaming. Comment about intelligence? Mind shaming. Wrong pronoun by mistake? Some kind of phobia. Didn't express full throated support for the cause? Must be a nazi! Into the gulag! Bought an... anything really -> capitalist pig!