27M Fewer Car Trips: Life After a Year of Congestion Pricing | Hacker News Reader

27M Fewer Car Trips: Life After a Year of Congestion Pricing

nytimes.com

non-paywall link: https://www.nytimes.com/interactive/2026/01/05/upshot/conges...

Sounds like a good reason to not invest in parking garages.

That's valuable real estate for housing. House people, not cars.

The first graph makes no sense? Why are the initial actual and expected values so far apart? Shouldn't they start at the same point?

They don't describe the graphic very well in the article, but they do link to the source data [1]. The "Expected" line seems to refer to a historical average. Since the starting point of the graph coincides with the beginning of congestion pricing, we would expect a difference between the two values at that point.

[1] https://metrics.mta.info/?cbdtp/vehiclereductions

I never understood why big, congested cities in the USA (NYC, Boston, L.A., D.C., Chicago) aren't dumping money into funding FSD research hand over fist. It's not a moonshot anymore, and it would be the game-changer of the century in terms of public transportation and GDP. This is a long-term no-brainer for prosperity.

In what world do you get that conclusion? Dense cities in other parts of the world rely on mass transit to move people. FSD so you can have self driving cars in the street -> ? -> increasing congestion. The point is you should have more effective volume transit not optimizing random ones. 1000 cars on FSD are an optimization better than 1000 taxi drivers, compared to a train or a few buses.

> Dense cities in other parts of the world rely on mass transit to move people

But they don’t solve the fundamental problems with mass transit: comfort, convenience, and trip times.

I was just at Disney World and joking to my wife that the park is propaganda to get people to use public transit because Walt loved trains. (You can’t get into the parks by driving. Only the train, bus, or gondola. If you drive you have to park at this giant lot and take the train from there.)

But even within that self contained environment—where land for transit infrastructure is basically free because Disney bought it all decades ago—public transit still isn’t great. Trying to get three kids and all their shit out the door to catch a bus or train, having to fold up strollers, etc., just sucks in comparison to throwing them into a car.

Clarification: only Magic Kingdom has that extra step of train/ferry/bus transportation from the parking lot. For all the other parks at Disney World, you can drive in and walk to the entrance. (There are trams if you're far out, but you can also walk.)

Yes, Walt did want that extra step of separation from the real world. Then Disney realized the logistical problems with it and didn't repeat it for the other parks, but they're stuck with it at Magic Kingdom. (And it also acts as an upsell for the premium resorts that are positioned right next to Magic Kingdom in walking distance.)

Let me tell you something about Magic Kingdom: Everything between the parking lot and the rides exists the way it does in order to SLOW YOU DOWN so you spend more money. All of it! Okay, maybe not the parking lot trams, but all their other gimmicks are just part of a funnel to keep you away from the rides as long as possible and once you're inside, to keep you from leaving.

Would you even be in favor of a public transportation system that did what you’re asking for? If MAJOR_CITY had a bill for an Uber-like system where you could hail a car subsidized by the taxpayer or even free to give you a ride?

Or are you against the idea of “public transportation” (transportation costs shared by taxpayers) and your criticisms of its quality or convenience are really moot because you are ideologically against the premise?

1000 buses on FSD > "a few buses". Bus drivers union would never allow that though.

Even the current amount of buses with some automated routing and phone booking would be a tremendous improvement. (Sure, there are accessibility concerns to address)

If you have FSD you don't need a bus drivers union. FSD can drive the buses.

What's the theory of change here? FSD fundamentally is going to make keeping a car moving on the road cheaper, and making something cheaper makes it happen more.

It eliminates traffic, parking, and alll the other pain points of owning a vehicle just to get from A to B when a car is the only true option. Certainly, FSD buses would be a win-win for cities too.

So instead of parking the FSD cars will be dead-heading from one pickup to another, increasing traffic.

It's important to make the distinction that flowing traffic and sitting traffic are different things to people. I really don't think a flowing river of FSD is worse than a static jam, but I could be wrong here, as there has never been a full self-driving city.

It doesn't eliminate traffic without congestion pricing. FSD reduces the annoyance cost of driving in traffic, which means there's going to be a lot more traffic.

It's very much a question mark whether FSD would eliminate traffic. If people can zone out and be on their phone while their car drives them, that encourages a lot more trips which might not otherwise be taken because of bad traffic. I can easily see FSD making traffic much worse.

FSD could largely eliminate privately owned vehicles, it could also allow cities to get rid of most parking infrastructure.

But a good mass transit system, pedestrian/cycling infrastructure, and efficient urban design are already proven ways of doing that.

FSD can make mass transit cheaper. Imagine not having to pay bus drivers' salaries. Being able to adjust vehicle sizes to the route's demand dynamically.

The biggest win is probably dynamic routing, just select your pickup-point and a destination and a bus will get automatically routed. You'd never be forced to waste time driving past a stop for which there's no customer demand on that particular trip.

Doesn't work (IMO). Very functional mass transit lives and dies on predictability. Having dynamic routing would be the antithesis to that. Maybe your trip will take 20 minutes, maybe it'll be 1 hour. It'd be impossible to tell which one it'll be because the route changes based on when you request and who else has requested.

If you wanted something like dynamic routing, then what you'd do is have it as a supplement to standard routing. Effectively taxi to the nearest bus stop.

For the same amount of trips, this system could reliably allow shorter and more frequent trips than previously possible. Given that the system would work better, it would need to scale up to meet increased demand.

There's absolutely no reason for dynamic routing to not reliably be faster than or as fast as static routes.

And FSD would just be one more thing to add to that list.

They come with fundamental compromises that Americans aren’t willing to live with, namely having to adhere to schedules, ride with other people, and not going directly to their destination.

Not just Americans, all the big European cities with good public transportation are usually full of cars.

Imagine how much worse it would be without the public transportation siphoning off so many riders.

For sure, but in many places it just couldn't realistically be much worse and the main consequences would probably be on the local economy rather than the amount of road use. Less people would be able to travel at all, inevitably leading to reduced need for travel.

That’s public transportation except tiny vehicles taking one person at a time instead of large vehicles taking many. It’s not an improvement.

Why do you think it's not an improvement over tiny vehicles used by only one person ever? A single Waymo can replace multiple private vehicles.

You could also create virtual paths, whereby you're heading north in one Waymo until say 38th street, and then you hop out and grab another waiting for you in just 30 seconds. Now you move east for 5 more blocks and arrive home without fiddling around at any other stops or stations.

Sure, and you could totally do this with multiple passengers at a time too. You could even profile your passengers to avoid any unpleasant partner choices, restrict this to specific hours, etc.

You could even design vehicles for transporting multiple individual passengers in totally separate spaces.

There are endless improvements to the status quo you can achieve with self driving vehicles, things which will simultaneously improve quality of life for literally everybody.

It can replace multiple private vehicles sitting at home doing nothing. Moving individuals in individual vehicles cannot replace individual vehicles moving individual people on the road at one time.

You assume FSD would jam traffic as it does with human drives, but you need to make the case for this as it's apples and oranges in terms of traffic. Why almost all traffic jams occur is distracted and poor driving.

>Why almost all traffic jams occur is distracted and poor driving.

Traffic jams most often occur during periods of peak usage (rush hour). How much of this is attributable to driver attention vs the inherent inefficiency of many independent vehicles attempting to coordinate speed, position, exiting, entering, etc? I don't take for granted that independent (vs synchronized) FSD would be significantly better.

Exactly. If the solution is not fewer vehicles on the road then it is not inherently going to reduce traffic congestion. More vehicles take up more space. There’s no way around that and it’s why municipalities keep needing to expand highways every few years but congestion never decreases.

I disagree in part. FSD cars driving independently could still leave green lights with less wasted time (inattention [read: phones], reaction time), could also be much less prone to “blocking the box”, and could avoid most instances of multi-minute double-parking (by driving around or driving to park safely/legally). All of those would reduce traffic congestion without reducing cars on the road and even with a modest increase in total vehicle miles driven.

FSD cars that coordinated with each other could leave lights even more quickly and better collaborate to zipper, observe/communicate/predict lights and modulate speed to prevent excessive stopping, etc.

A world of robotaxis requires a huge percentage increase in the number of cars on roads because you will need many empty cars on the roads at all times repositioning or picking up passengers.

I can’t see how that won’t negate and even be worse than any benefit from improved reaction times.

Any attempt to solve for repositioning just takes you closer and closer to buses or trains.

>you will need many empty cars on the roads at all times

Not necessarily. FSD services would probably optimize for occupancy, which would mean limited and unpredictable availability for customers. Since the fleet is a capital investment rather than being floated by gig workers, supply would presumably be more constrained than Uber etc are now, and we see what happens at peak demand with them. I don't see that business logic changing between Uber drivers and FSD.

Why not have the FSD services run on predetermined routes along high density corridors on a schedule? Then they would be filled optimally on average.

Given reasonable lead times on bookings, you'd need less cars on the road per trip than now. Especially since demand tends to be predictable.

The really big win here is parking and time spent looking for it. Self-driving trips can just be shorter

If you have 100 people who want to get somewhere in their own car at the same time, that requires a minimum of 100 cars. The lead time doesn’t factor into it.

Parking is a problem because of our dependence on cars. You also don’t need to park if you take a bus or a train and the things you want to get to are built near the bus and train stations.

Those cars have to spend less time on the road because they don't have to spend time on parking, this leads to less car-hours on the road for the same trips. Those cars will also be faster, safer and pick better routes than humans.

> You also don’t need to park if you take a bus or a train and the things you want to get to are built near the bus and train stations.

It is nonsensical to compare self-driving cars against buses or trains in a situation where we still have tons of private cars on the road.

FSD can totally improve buses too, and well-designed multi-passenger vehicles can certainly easily end up making up most of the fleet. You could for example seat 4 people in completely isolated spaces without needing outrageously large vehicles. That'd be great for serving commutes where loads of people are going to the same areas.

We're not disagreeing with each other. If we can have robotaxis that primarily move more than 1 person at a time then that's a good thing. But if "loads of people are going to the same areas" then those robotaxis should resemble buses.

>But if "loads of people are going to the same areas" then those robotaxis should resemble buses.

Should, but if you really want to sell it to the public, you want to keep the service as close as possible or better than what's currently available. That's more feasible with fewer passengers on a vehicle, too many stops will easily double your travel time.

Today’s cars that are driving around (slowly and less predictably) looking for parking are functionally empty even if they’re not literally so. Those foregone miles will partially offset the deadheading miles.

Why do you think that’s true?

When 100 cars hit a decrease from 4 lanes to 3 you are going to have a jam no matter how the cars are driving.

When we continue using individual transportation to allow suburbs to expand further and further from the places people want to go roads will continue to fill and traffic will slow and jam.

Why do you think FSD cannot handle a simple zipper merge?

Just for another point, cars need to slow down to turn. There’s no way around that and it has nothing to do with reaction times. Robotaxis behind could anticipate that and slow down gradually to improve flow, but they still have to slow down just as much.

We can make the roads straighter with more gentle curves and robotaxis can drive 100mph you say!

Keep going…

>cars need to slow down to turn.

Cars traveling at a safe speed do not need to slow down in a turn. If the friction on the 4 wheels doesn't result in oversteer nor understeer, you just keep going through. So what are you referring to? Laws of nature? Laws of the road?

I don’t know what you mean. What is a safe speed? It is not possible to make a 90 degree turn at a stoplight intersection at 45 mph.

It can but it requires slowing down regardless. If you have the same number of vehicles doing a zipper merge you will have a jam. There’s no way around that. Add in that you will probably have to have vehicles with no passengers repositioning or picking up passengers it will quickly lead to as bad or worse congestion.

Number of cars isn't the relative metric for congestion, it's number of miles driven. FSD makes driving easier / cheaper / better. It'll increase the number of miles driven.

https://www.youtube.com/watch?v=040ejWnFkj0

Reply on news.ycombinator.com