How we can reduce traffic congestion(research.google)
research.google
How we can reduce traffic congestion
https://research.google/blog/the-power-of-collaboration-how-we-can-reduce-traffic-congestion/
79 comments
Surely the top way to avoid traffic congestion would be communities where it's possible to live near where you work, shop, go out, etc. and not doing everything else exactly the same but taking a slightly different highway in your car
This is possible if you’re not picky about where you live, where you work, your career options, how crowded your local vicinity is, or how much you pay for your residence.
The more your preferences or financial constraints come into play, the more you have to give up.
Most people settle in for driving because it allows them to pick from more job options than those that happen to be located near their house and more housing options than what happens to be near your job.
This didn’t matter as much 200 years ago when most people’s job options were limited to farming or something in service of farming.
It got much harder when the range of people’s jobs exploded and finding a company hiring in your specialty meant traveling some distance from home.
It gets even harder when there are two earners in a household trying to find two jobs.
The more your preferences or financial constraints come into play, the more you have to give up.
Most people settle in for driving because it allows them to pick from more job options than those that happen to be located near their house and more housing options than what happens to be near your job.
This didn’t matter as much 200 years ago when most people’s job options were limited to farming or something in service of farming.
It got much harder when the range of people’s jobs exploded and finding a company hiring in your specialty meant traveling some distance from home.
It gets even harder when there are two earners in a household trying to find two jobs.
> This is possible if you’re not picky about where you live, where you work, your career options,
Yup.
And even if you arent't picky. The amount of surface area you can cover scales quadratically with the distance you can commute (either by traveling longer, or by going faster). So as a first approximation, the amount of competition for your labour also goes up quadratically.
Job-hopping is one of the best ways to get better jobs. And it is a LOT easier if you can commute further.
Yup.
And even if you arent't picky. The amount of surface area you can cover scales quadratically with the distance you can commute (either by traveling longer, or by going faster). So as a first approximation, the amount of competition for your labour also goes up quadratically.
Job-hopping is one of the best ways to get better jobs. And it is a LOT easier if you can commute further.
If you don't have a community like that, then the best way is congestion pricing.
The best way is to change our communities, even if that takes time and money.
It is difficult for me to admit I'm an idiot but when I was younger and living in an apartment, I loved the idea of a single family home. And now that I'm living in a single family home, I feel like I was wrong all along. Not that I want to go back to the apartment I was in before. Dear lord no but the idea of a mixed use building not too tall only like first floor with high ceilings for business or shops with two or at the most three floors above for residential units feels like the ideal sweet spot. Ideally with a lot of these close together to have everything I need within a walking distance but also a subway station within a walking distance if I need to go farther.
Like everything else community construction responds to incentives. So we need to structurally incentivise short distance commute communities. Congestion pricing seems like a reasonable first step.
What if you don't want to live in a dense community?
Well just live somewhere that is so lacking in density there is no congestion.
Or a small town that is surrounded by farms.
Just avoid suburban housing as far as the eye can see with a limited number of roads everyone gets funneled on to.
Or a small town that is surrounded by farms.
Just avoid suburban housing as far as the eye can see with a limited number of roads everyone gets funneled on to.
Then you don't. But don't expect people who live in urban centers to cater to your needs when you don't live there.
In that case antifa will force to commit seppuku. You will have no other choice. Freedom isn't free.
One of the things this type of intervention doesn't take into account is that different roads are built with different levels of hardiness based on the amount of traffic they are expected to receive.
For instance, a few years ago, a segment of I-495 in Delaware needed to be unexpectedly shut down for emergency repairs. Drivers were rerouted. But because of the increase in traffic on the less-hardy detour route, that route needed repairs and repaving soon afterward, much more quickly than it would have ordinarily required.
So yes, drivers can be better dispersed to ease congestion, but we also need to consider the secondary effects to the roadways themselves.
For instance, a few years ago, a segment of I-495 in Delaware needed to be unexpectedly shut down for emergency repairs. Drivers were rerouted. But because of the increase in traffic on the less-hardy detour route, that route needed repairs and repaving soon afterward, much more quickly than it would have ordinarily required.
So yes, drivers can be better dispersed to ease congestion, but we also need to consider the secondary effects to the roadways themselves.
A random factoid that will always stick in my brain is that the damage a vehicle does to a road is proportional to the weight on an axel...to the fourth power. I suspect rerouting semis to the roadway is by far the greatest factor.
Another random fact is that Norman Mailer coined ‘factoid’ to refer to a fabrication presented as fact, but now means the opposite (as in, a fact presented as a fact, not a fact presented as fabrication).
So it’s now one of those words like ‘literally’ which can be its own antonym.
So it’s now one of those words like ‘literally’ which can be its own antonym.
The same things keeps happening every time I find myself stuck in traffic on the interstate. Out of nowhere, a popup appears in Google Maps: a faster route is available! 4 minutes faster! Unless either the passenger or the driver are fast enough to hit "No thanks", the change auto-applies, and Google now wants me to exit the interstate at the nearest exit and drive some random road I had no idea about, to rejoin the interstate a few miles ahead. Of course, a bunch of other vehicles in the same traffic jam got the same
notification, so that minor road now get a sizable fraction of the interstate traffic, all of which then struggles to merge back.
Seeing this again and again. We call it a "Google detour" in the family, and rarely agree to the change of the route.
Seeing this again and again. We call it a "Google detour" in the family, and rarely agree to the change of the route.
I’ve just started taking surface roads out of Charlotte at peak hours because I know how to get around, and any route that’s part of Apple/Google maps defaults will invariably be clogged with everyone following their directions. Surface streets tend to be blissfully open these days.
Same. This is why I switched to Apple Maps. Sometimes the Google detours would end in dangerous situations, like a left turn with no light across a major road. And it would be to save 2 minutes-ridiculous!
I've had Google try to route me across private property (an apartment complex parking lot) to avoid a signaled intersection and save a couple of minutes.
Apple Maps does this too but the threshold seems to be higher - it's a lot less willing to do it.
Me too. It’s infuriating and unsafe. I don’t drive often, but when I do it’s out of the city where I’m unfamiliar and need a map.
So I also stopped using Google Maps for driving.
Who at Google seriously believes that it’s good idea to 1) unpredictably change the route someone chose mid-drive, and 2) to distract them while driving with a pop up notification that must be interacted with just to maintain the route.
If I choose a route, I chose it for a reason. Don’t change it while I’m driving.
So I also stopped using Google Maps for driving.
Who at Google seriously believes that it’s good idea to 1) unpredictably change the route someone chose mid-drive, and 2) to distract them while driving with a pop up notification that must be interacted with just to maintain the route.
If I choose a route, I chose it for a reason. Don’t change it while I’m driving.
Now they did the obvious thing and load balanced the alternative routes. Somebody could have done this long ago and got a promo.
> For this study, the Google Maps algorithm was modified to prefer alternative routes with similar travel times and segment types, effectively guiding trips away from the pre-selected congested segments
> Over a six month period, we adopted a city-wide switchback (also known as crossover) experimental design, alternating between this treatment and the control (unaltered) routing algorithm over consecutive days to appropriately measure the effect of this intervention
> Averaged across cities, we observe a median increase of around 2% in driving speeds on targeted segments, corresponding to a median decrease of 0.5% to 1.0% in fuel consumption rates
The cities were: Atlanta, Boston, Chicago, Los Angeles, Miami, New York, Philadelphia, Salt Lake City, San Francisco, Seattle.
The data and code is also available (https://github.com/google-research/google-research/blob/mast...) from the paper (https://www.nature.com/articles/s44284-026-00443-x).
Kudos Google! Nice to see this kind of work. That said, let's just build more trains?
> Over a six month period, we adopted a city-wide switchback (also known as crossover) experimental design, alternating between this treatment and the control (unaltered) routing algorithm over consecutive days to appropriately measure the effect of this intervention
> Averaged across cities, we observe a median increase of around 2% in driving speeds on targeted segments, corresponding to a median decrease of 0.5% to 1.0% in fuel consumption rates
The cities were: Atlanta, Boston, Chicago, Los Angeles, Miami, New York, Philadelphia, Salt Lake City, San Francisco, Seattle.
The data and code is also available (https://github.com/google-research/google-research/blob/mast...) from the paper (https://www.nature.com/articles/s44284-026-00443-x).
Kudos Google! Nice to see this kind of work. That said, let's just build more trains?
I read the article and didn't see anywhere if they collaborated with city planners, or just ran this on their own. I get the techno-optimism of making traffic 'better' and also it may be concerning if trucks are being routed through neighborhoods where planners didn't build for it.
I think that's already very much a problem, and given that they constrained it to routes that didn't have a significantly different drive time the risk seems low.
When a person driving a large commercial truck relies solely upon Google Maps for routing, they're already on the wrong course.
Google Maps doesn't have a "truck mode." It does not take things like size or weight or blanket restrictions on commercial truck traffic into account.
This means that Google Maps will cheerfully send commercial trucks down roads where they do not belong even on a normal day that is unfettered by whimsical techbro experiments, and the presence of such experiments on any other day doesn't change that.
Truck drivers do have a plethora of truck-centric navigation systems available to use, but Google Maps not amongst them. It never has been.
Google Maps doesn't have a "truck mode." It does not take things like size or weight or blanket restrictions on commercial truck traffic into account.
This means that Google Maps will cheerfully send commercial trucks down roads where they do not belong even on a normal day that is unfettered by whimsical techbro experiments, and the presence of such experiments on any other day doesn't change that.
Truck drivers do have a plethora of truck-centric navigation systems available to use, but Google Maps not amongst them. It never has been.
Found the European :)
The south SF Bay Area cities of Los Gatos and Monte Sereno have persistent problems with traffic gridlock during summer weekends and holidays due to navigation apps routing drivers off of southbound SR-17 and onto surface streets. It gets so bad that residents literally can't get out of their own driveways and emergency response vehicles can't move.
There actually did used to be train service from San Jose to Santa Cruz but it was abandoned in 1940 due to high costs and lack of use. Rebuilding it would cost >$1B.
https://www.goodtimes.sc/isnt-train-san-jose/
There actually did used to be train service from San Jose to Santa Cruz but it was abandoned in 1940 due to high costs and lack of use. Rebuilding it would cost >$1B.
https://www.goodtimes.sc/isnt-train-san-jose/
Traffic apps only know about congestion if someone running the app goes down the congested road. Because of this, I've always suspected that the apps, from time to time, will route someone down a route they haven't gathered data on in a while, just to collect the data, and even if the route is likely to be suboptimal.
> running the app
At least for Apple, iPhones always report this data, not just when using Apple Maps
At least for Apple, iPhones always report this data, not just when using Apple Maps
>I've always suspected that the apps, from time to time, will route someone down a route they haven't gathered data on in a while, just to collect the data, and even if the route is likely to be suboptimal.
I can't say this actually happened for me. For straightforward routes with no congestion I never saw random alternate routes being proposed. That makes sense, given that it'd probably tip people off. If this is happening, they must only be doing in cases where there's congestion and the difference is marginal, eg. it's rush hour and the "optimal" route takes 30 minutes but the alternate takes 33 minutes. Moreover you don't really need any deliberate effort to see this effect. If nobody is traveling on a side road, the algorithm will probably revert to historical patterns, which might turn out to be overly optimistic in congestion scenarios (eg. there's nearby road repairs and other people are already using it as an alternate), thereby giving you the impression that you got screwed over by the app.
I can't say this actually happened for me. For straightforward routes with no congestion I never saw random alternate routes being proposed. That makes sense, given that it'd probably tip people off. If this is happening, they must only be doing in cases where there's congestion and the difference is marginal, eg. it's rush hour and the "optimal" route takes 30 minutes but the alternate takes 33 minutes. Moreover you don't really need any deliberate effort to see this effect. If nobody is traveling on a side road, the algorithm will probably revert to historical patterns, which might turn out to be overly optimistic in congestion scenarios (eg. there's nearby road repairs and other people are already using it as an alternate), thereby giving you the impression that you got screwed over by the app.
I wonder this same thing when I’ve been routed completely asinine ways off interstates at night when traffic appears calm. I always have to play the game of “is there horrendous traffic ahead from night paving / accident, or am I being conscripted as a traffic sensor robot?”
Government data sources can input real time data into Google Maps [1]. So, it's more likely than not that local police or state DoT is behind that.
[1] https://contentpartners.maps.google.com/
[1] https://contentpartners.maps.google.com/
Doesn't have to be true. My state has public camera feeds for various highway stretches. Too low-detail to identify vehicles but easily enough to detect congestion.
This would sort of happen naturally if they routed as if roads with no data in the past N minutes/hours were at full speed.
"Hence, the efficient use of transportation networks is of paramount importance."
Perhaps some sort of carpooling profile? That would be a dramatically bigger improvement than, say, routing users through residential neighborhoods.
Perhaps some sort of carpooling profile? That would be a dramatically bigger improvement than, say, routing users through residential neighborhoods.
How would Google help with a carpooling profile?
They are looking at ways they can improve traffic that are actually in their control. They can change how they route traffic that is using their app, they can’t change public policy or driving choices. They are working with what they have.
They are looking at ways they can improve traffic that are actually in their control. They can change how they route traffic that is using their app, they can’t change public policy or driving choices. They are working with what they have.
Much as they have features for walk / bike / transit traffic, they could suggest step-by-step carpool instructions:
"1. meet with (other Google Map carpool user) X at location Y.
2. In one car, both of you drive to location Z."
Obviously, huge challenges here (is person X a serial killer, etc.) But Google can handle moonshots.
Obviously, huge challenges here (is person X a serial killer, etc.) But Google can handle moonshots.
> Obviously, huge challenges here
Social credit score? I've seen that Black Mirror episode.
Social credit score? I've seen that Black Mirror episode.
Is this the comment for me to snarkily reinvent trains and trams and buses on?
All attempts to reimagine transport are train but worse, except for the occasional bike but worse.
Every now and then, an especially inventive inventor manages to do both at once. And that's how you get the Shweeb.
https://youtube.com/watch?v=7qNOtgrIjO4
Every now and then, an especially inventive inventor manages to do both at once. And that's how you get the Shweeb.
https://youtube.com/watch?v=7qNOtgrIjO4
Congestion can be solved by charging more for driving. Even a modest amount would start affecting how much people drive. The money could be used for better roads and improving other transit options that aren't so space-inefficient. That said, this would likely be unpopular to implement until the effects were visible. See congestion pricing in NYC as an example.
Won't that just unfairly displace the impact onto the economically disadvanteged as they are the least likely to have the flexibility in their schedule, inadvertently forcing more of the maintenance burden onto those who are int be least place to bear it?
If we could copy the traffic laws of a country like Germany to the US, I think that would have the biggest + cheapest effect. I am OK with automated/elevated enforcement if it means stop & go traffic evaporates into free flowing conditions.
We should also take the idea from Finland where the traffic fines scale with each person's ability to pay. $100 for camping the passing lane or failing to maintain a reasonable following distance is not a big consequence for a lot of people. $100k covers the edges a lot better.
https://www.theguardian.com/world/2023/jun/06/finnish-busine...
We should also take the idea from Finland where the traffic fines scale with each person's ability to pay. $100 for camping the passing lane or failing to maintain a reasonable following distance is not a big consequence for a lot of people. $100k covers the edges a lot better.
https://www.theguardian.com/world/2023/jun/06/finnish-busine...
I wish there was more police presence to spot lane-camping and fine them in Germany, too many idiots do it and get away with it.
If I ran Google Maps, I'd ask to route stupid drivers away from my routes. The GPS and phone accelerometer should be able to tell us who they are -- "Oh you have Google Maps actively navigating, GPS says you're going 50mph, and the app in focus is WhatsApp and you're using the phone keyboard? Fuck off! Also we recorded 5 swerve events in the last 10 minutes, hard to stay on your lane when you're texting!"
It'd be unethical, but man it'd be magical...
There's custom software for Elon's Tesla, I wonder if the cloud-based navigation system also directs people away from his routes so he can have a ride on emptier roads...
If I ran Google Maps, I'd ask to route stupid drivers away from my routes. The GPS and phone accelerometer should be able to tell us who they are -- "Oh you have Google Maps actively navigating, GPS says you're going 50mph, and the app in focus is WhatsApp and you're using the phone keyboard? Fuck off! Also we recorded 5 swerve events in the last 10 minutes, hard to stay on your lane when you're texting!"
It'd be unethical, but man it'd be magical...
There's custom software for Elon's Tesla, I wonder if the cloud-based navigation system also directs people away from his routes so he can have a ride on emptier roads...
People hate patronizing systems in their cars already, not sure this would help
The idea is the system would just judge terrible drivers quietly, and then route them away from my route whenever I'm on the road.
Of course the first step of that is I have to gain control of Google Maps...
Terrible drivers cause traffic jams and accidents, who wouldn't want to be segregated away from them?
Of course the first step of that is I have to gain control of Google Maps...
Terrible drivers cause traffic jams and accidents, who wouldn't want to be segregated away from them?
Which traffic laws are you proposing copying? I'm having a hard time understanding how larger fines can lead to less congestion.
>During “treatment” days, the modified routing guided all trips that encountered the pre-selected congested segments toward alternative routes with similar travel times.
Why would they specifically need to route people away from congested segments? Presumably if a segment gets congested enough, it'd be considered slower and therefore won't get picked in the first place?
Why would they specifically need to route people away from congested segments? Presumably if a segment gets congested enough, it'd be considered slower and therefore won't get picked in the first place?
Because those roads are still maybe 30 seconds or 60 seconds faster on paper and critically they're the major roads with minimal intersections, which all apps prefer.
Probably many reasons but here’s one demo: https://en.wikipedia.org/wiki/Braess%27s_paradox
Every actor acting rationally in their own interest can get to a worse equilibrium than if they were coordinated(in this case, to completely ignore the new edge). There are many other examples of this in game theory, you should look it up.
Every actor acting rationally in their own interest can get to a worse equilibrium than if they were coordinated(in this case, to completely ignore the new edge). There are many other examples of this in game theory, you should look it up.
Another question: they say road speeds increased, great. But that’s a different metric than average drive time. Curious if that also decreased.
I think we need some law that if you are above a certain scale you have to publish traffic data as a gtfs feed, ie basically apple and google have to.
Europe addressed the problem by hanging the 2% criminal population each year for about 800 years.
This exerted strong evolutionary and social selection on social perception of safety. Sharing public transportation accelerated.
I won the lottery of life, born in a British colony in the latter half of the 20th century. Unlike the post mass immigration Europe of today, it is perfectly safe for me to catch public transport where I live.
I have the luxury of choosing safe public transport where sufficient patronage exists to make it cost effective.
Where WEF demographic replacement policies are implemented, public transport patronage will continue to plummet.
This exerted strong evolutionary and social selection on social perception of safety. Sharing public transportation accelerated.
I won the lottery of life, born in a British colony in the latter half of the 20th century. Unlike the post mass immigration Europe of today, it is perfectly safe for me to catch public transport where I live.
I have the luxury of choosing safe public transport where sufficient patronage exists to make it cost effective.
Where WEF demographic replacement policies are implemented, public transport patronage will continue to plummet.
Happy that research time is being put towards this, however a fuel use decrease of ~0.75% is a bit underwhelming for this particular endeavor, even when consumer cars/vans are 10% of CO2 emissions.
I think it's a mistake to represent average speed increase instead of characterizing the speed increase as as hours of full, moderate, and low speed traffic per day.
Because an extra ??minutes a day of avoiding stop and go traffic is worth far more than the average speed increase it tells.
Because an extra ??minutes a day of avoiding stop and go traffic is worth far more than the average speed increase it tells.
I got an idea: let people work from home again.
Great, Google, you want to reduce traffic congestion? Give me the ability to say "Avoid left turns" in your directions.
Until you support a feature that simple and obvious, I don't have a lot of interest in your input on this subject.
Until you support a feature that simple and obvious, I don't have a lot of interest in your input on this subject.
Why cant we have smart stop lights. Nothing more annoying than sitting on a street with nobody coming and a red light for some arbitrary time period that's totally incorrect for the time period I'm currently in
Also, left turn lanes that are too short for the average number of cars wanting to turn left, and left turn signals that are too short to clear the left turn lanes.
Most cities I've lived in have these in the US...
I've lived places where stop lights were all scheduled (unless someone was operating it manually), but most of the lights I experience operate dynamically based on sensors (typically in the road or cameras and ped buttons)
Relevant XKCD: https://xkcd.com/277/
Most cities have some intelligence on their traffic lights, and they do have traffic sensors to know where cars are waiting.
You might not see any cars and are annoyed waiting at the light, but you don’t know what downstream things they are trying to control for. Maybe if they send you through the light, you are going to join some other traffic event that will cause an issue.
It could also just be suboptimal, but it very hard to know just from what you observe as an individal
Most cities have some intelligence on their traffic lights, and they do have traffic sensors to know where cars are waiting.
You might not see any cars and are annoyed waiting at the light, but you don’t know what downstream things they are trying to control for. Maybe if they send you through the light, you are going to join some other traffic event that will cause an issue.
It could also just be suboptimal, but it very hard to know just from what you observe as an individal
They exist. Your city needs to set it up. They can also switch to flashing red lights.
Interesting, I always just assumed they were already doing this.
When Google Maps routes me using a smaller secondary road instead of the main road that I would otherwise have used , I've always wondered whether that significantly changes the amount of traffic that smaller road sees. It's funny to consider that arbitrary black-box changes to the routing algorithm can have a noticeable effect to people that live there.
Well, duh. Grid design that allows traffic to diffuse is a secret superpower of American cities. Along with stroads that seamlessly blend local and arterial traffic.
One of unforgivable mistakes of Project Zero Vision is sabotage of stroads. If forced more traffic onto local streets, resulting in MORE pedestrian deaths.
One of unforgivable mistakes of Project Zero Vision is sabotage of stroads. If forced more traffic onto local streets, resulting in MORE pedestrian deaths.
Do you have stats to support your statement?
Sure. Pedestrian deaths are above the 2015 levels in all the large West Coast cities that went full-on with the Zero Vision project. Numbers are for 2015 and 2025.
Seattle: 7/18
Portland: 11/20
LA: 130/150
SF is unchanged at 24 (they had a HUGE drop from 2024, luckily).
And no, the following excuses do not apply:
COVID - deaths started growing _before_ COVID.
Car size increase - cars did not increase significantly during this time.
Population increase - ditto.
Seattle: 7/18
Portland: 11/20
LA: 130/150
SF is unchanged at 24 (they had a HUGE drop from 2024, luckily).
And no, the following excuses do not apply:
COVID - deaths started growing _before_ COVID.
Car size increase - cars did not increase significantly during this time.
Population increase - ditto.
Where isn't there traffic congestion?
Hey I patented this idea about a decade ago:
https://patents.google.com/patent/US20170184409A1
(I'm not saying I'm the first or only person to think of it, but I did patent it, as well as the extra claim of compensating those people sent on the slower route).
https://patents.google.com/patent/US20170184409A1
(I'm not saying I'm the first or only person to think of it, but I did patent it, as well as the extra claim of compensating those people sent on the slower route).
did you build anything tangible with this idea?
For over a decade, I imagined that if I ever landed a job at Google, this would be my most significant project. It made me chuckle a bit when I read the announcement, they finally built it! confirming that my thoughts weren’t entirely delusional XD
The way to maximise traffic congestion would be to remove trucks off the road during peak times, banning trucks from the fast lane at all times, making it the social norm to toot someone in the fast lane so they move over.
I have a lot of difficulty thinking those changes alone would solve congestion. I’m especially thinking is ski traffic along I70 from Denver to the mountains. The issue is just volume of passenger vehicles, and there are no other realistic routes
Just drive anywhere with more than usual density in traffic and you’ll find trucks in the fast lane when they stop and start create gaps in the fast lane where no traffic can go. If you took out trucks altogether during peak hours you wouldn’t have these slow bubbles of traffic at the worst times..
Edit: let’s think of this from a pure scientific point of view - if you had 3 lanes and split traffic across them based on a range of speed - that would be the most optimised in terms of throughput for all lanes. Now, consider a reverse Amdahl's Law… what’s the worst thing you could do to make the fastest lane crawl which in effect kills total throughput across ALL lanes? Put a slow truck in it! Put a few, and you’ve just turned the lane giving you the highest throughput to most likely the slowest lane.
I just parked my car after another morning of commuting. Thought experiments alone in today’s traffic again confirmed my theory.
Edit: let’s think of this from a pure scientific point of view - if you had 3 lanes and split traffic across them based on a range of speed - that would be the most optimised in terms of throughput for all lanes. Now, consider a reverse Amdahl's Law… what’s the worst thing you could do to make the fastest lane crawl which in effect kills total throughput across ALL lanes? Put a slow truck in it! Put a few, and you’ve just turned the lane giving you the highest throughput to most likely the slowest lane.
I just parked my car after another morning of commuting. Thought experiments alone in today’s traffic again confirmed my theory.