I agree with the underlying premise here that the ease and relative comfort of driverless cars is likely to induce a substantially higher degree of demand for transportation, but this piece doesn’t deal with any of the potential ways that driverless technology could reduce the burden on road space per unit of time.
And in the case of driverless cars, it seems like there will be quite a few (e.g. instant communication between vehicles reducing the communication problem of gridlock,
faster average speeds, narrower lanes because of less need for room for human error, etc.)
The underlying premise of you piece is that (similar to the aquifer) space on roads is a scarce resource that has historically been unpriced because the allocative benefit of pricing (in many instances) is swamped by the transaction costs (or simply doesn’t exist because the road does not have more demand than capacity). But as more demand is unlocked and those limits are met, the allocative benefit grows, so we should price them now for political economy reasons.
Which, might be true? But the thing that needs to be accounted for is ~approximately~ demand on road space per unit of time, not demand for transportation generally, and under that framework, it’s not clear that this self-driving vehicles actually do increase demand. At a minimum, there’s substantial accounting for counterarguments here.
My view is that the latent demand for transport is essentially unlimited. Unlike most things, it simply cannot be satisfied. I think we take literally as much transport as we can, constrained only by road speeds and costs. So I don't think even doubling road capacity would make much difference.
Let me tell you how much I hate being in a car. Self driving doesn't mitigate this even a bit. From watching others while they are passengers vs drivers, my best guess is that most people feel exactly as I do. There's a lot to hate about being locked in a small box.
The real question is what survey data would tell us about various scenarios.
But your scenario seems wildly implausible to me. I agree there would be some people who adopted longer commutes and more road trips, especially among rich people who have no family or friends they'd rather spend time with, can afford the extra miles, and have nothing better to do. But that's not that many people, so how would they possibly *double* miles driven??
The exception I can see is commuting to a larger cheaper house, which brings us back to the housing theory of everything, but who knows how likely it is to add more traffic than the traffic that gets removed by improved AV traffic behaviors?
Despite disagreeing about all this, I agree what you're saying is interesting. I've always believed that there will be congestion pricing at least for company-owned robotaxi fleets and maybe for privately owned AVs too. The one political factor you don't mention is that people love to regulate big companies. For this reason I expect congestion pricing can be imposed on robotaxis at any time.
If you're saying for you personally, sure, but do try it and get back to us with how it goes.
For me, no. My wife has always loved to drive, so I'm already experiencing lots of driving as a passenger, including while commuting (we work near each other). I agree it's often more convenient than driving myself, but I, the passenger, have always worked hard to make sure we have the shortest commute possible.
You might look at studies of people's attitude toward commuting. My memory of those results is that they find that on net people hate commuting and they never stop hating it. I don't remember there being a special exemption for people who are passengers, but maybe some of the literature studies it specifically.
The question, of course, is whether enough people love sitting in a car that traffic becomes traffickier, but your vision, if I understand it correctly, assumes a widespread enthusiasm for auto transport that I believe we already know is not there.
Happy to be proven wrong here, but that seems like a fairly extraordinary claim. Do you have any evidence that latent demand for transportation being essentially unlimited?
I like the story, but I'd be interested in actually calculating the tradeoff between slowing adoption vs preventing gridlock.
Globally, 1.2 million traffic deaths per year is a current, tangible problem that self driving cars can address. Omnigridlock is a theroetical future problem that they MIGHT cause.
If we look at the math: 1.2 million traffic deaths per year x 80% reduction via self-driving cars, then that would mean ~950k deaths annually prevented.
If a preemptive congestion tax delays mass adoption by just an average of 3 months, that equates to roughly 240,000 lives lost compared to the counterfactual of delaying taxes until congestion becomes a real problem.
Yes, good cost benefit analysis, and good reminder to always start with the cost benefit analysis so as not to get lost in the weeds that are the wrong arguments.
Worth adding that AV safely will probably go the way airline safety has gone, where industry works to continue to reduce road deaths until they're down by much more than 80%.
I mean, we could do both? But if you look at the trends, one of them is happening (self driving cars) and one of them is not happening (mass transit, in America at least). And even outside of America, there are still a lot of deaths from cars in places with good public transit so... please come back to this reality lol
1. great story and examples with the aquifer, passenger pigeon, etc.
2. how do you know how many miles an AV drives and thus charge them per mile?
3. if you're taxing AV use, how much will that slow adoption? the common wisdom applies: "if you want less of something, tax it."
Seems like an alternative to just taxing AVs at higher rates would be to lean into lane tolls. One lane/rate for someone drinking beers and happy to go 10 miles an hour; another lane/rate for the commuter rushing to a meeting; another lane for emergency vehicles; etc.
Speeding the adoption of AVs saves lives! So we should be extra cautious of imposing policies that would slow down what will already be a difficult transition
I don't think we should charge them per mile necessarily. I think we should 'surge price' for congestion only. I agree it's a tradeoff against slowing adoption, but I won't let that imperfection be the enemy of the good.
I don't know where you get the idea that the demand for transport is unlimited. My personal demand for transport is very limited, and I suspect that I'm not much different than a lot of others. With more people working from home, conferences and meetings being held online, and ever more people shopping online, I wouldn't be surprised if transport demand goes down; not up.
There may very well be less cars on the road when self-driving cars are widely available, because many people won't even need to buy a car - why lay out large amounts of capital, $40,000 and up, and pay for maintenance and insurance, if you can just have a robo pick you up and drop you off?
I don't agree with the premise of unlimited demand. Traffic demand is driven by population and the distance you need to travel. The people stuck in gridlock right now aren't going to walk an hour to work in bad weather. They will stay in the gridlock.
As you said, "When self-driving cars become 90 percent of the cars on the road, they will be able to platoon and join up into little trains, saving the space usually spent on gaps between vehicles and doubling road capacities."
Waymo will increase road supply, but I don't foresee that being massively outpaced by road demand.
Waymo claims avoid making traffic worse by what they call 'slow and steady driving' and that their cars do drive in a way that avoids making traffic worse. I've heard the first part many times before, and the second part does seem like exactly the sort of thing that an automated driving system would be good at. I'm no expert, but it sounds like this may be another source of reduced traffic when more AVs are present.
Wow this is the most disappointingly car-brained thing I've read in WiP.
Yeah maybe it's a good thing that AV's will create massive gridlock: This will then incentive the use and development of a system which *can't* get gridlocked and can carry more capacity than any "Waymo train" ever could : That is, an actual mass transit system with actual trains.
This seems correct to me, but I wonder if we can't set some threshold level of (individual) use where by below this level the use of autonomous vehicles isn't taxed. This would seem to help avoid regressive effects, including (or especially) the regressive effect of non-autonomous vehicles being cheaper by comparison.
We've already experimented in London. Licencing Uber in 2012 saw PHVs rise from 45,000 to over 90,000. noticeably adding to congestion in central and inner London.
Note that prior to 2025 most Uber drivers used hybrid vehicles that were exempt from the congestion charge.
I imagine that, as with Uber, lobbying will decide what happens
I agree with the underlying premise here that the ease and relative comfort of driverless cars is likely to induce a substantially higher degree of demand for transportation, but this piece doesn’t deal with any of the potential ways that driverless technology could reduce the burden on road space per unit of time.
And in the case of driverless cars, it seems like there will be quite a few (e.g. instant communication between vehicles reducing the communication problem of gridlock,
faster average speeds, narrower lanes because of less need for room for human error, etc.)
The underlying premise of you piece is that (similar to the aquifer) space on roads is a scarce resource that has historically been unpriced because the allocative benefit of pricing (in many instances) is swamped by the transaction costs (or simply doesn’t exist because the road does not have more demand than capacity). But as more demand is unlocked and those limits are met, the allocative benefit grows, so we should price them now for political economy reasons.
Which, might be true? But the thing that needs to be accounted for is ~approximately~ demand on road space per unit of time, not demand for transportation generally, and under that framework, it’s not clear that this self-driving vehicles actually do increase demand. At a minimum, there’s substantial accounting for counterarguments here.
My view is that the latent demand for transport is essentially unlimited. Unlike most things, it simply cannot be satisfied. I think we take literally as much transport as we can, constrained only by road speeds and costs. So I don't think even doubling road capacity would make much difference.
Let me tell you how much I hate being in a car. Self driving doesn't mitigate this even a bit. From watching others while they are passengers vs drivers, my best guess is that most people feel exactly as I do. There's a lot to hate about being locked in a small box.
The real question is what survey data would tell us about various scenarios.
But your scenario seems wildly implausible to me. I agree there would be some people who adopted longer commutes and more road trips, especially among rich people who have no family or friends they'd rather spend time with, can afford the extra miles, and have nothing better to do. But that's not that many people, so how would they possibly *double* miles driven??
The exception I can see is commuting to a larger cheaper house, which brings us back to the housing theory of everything, but who knows how likely it is to add more traffic than the traffic that gets removed by improved AV traffic behaviors?
Despite disagreeing about all this, I agree what you're saying is interesting. I've always believed that there will be congestion pricing at least for company-owned robotaxi fleets and maybe for privately owned AVs too. The one political factor you don't mention is that people love to regulate big companies. For this reason I expect congestion pricing can be imposed on robotaxis at any time.
In my view self driving will ameliorate the pain of being in a car a lot.
If you're saying for you personally, sure, but do try it and get back to us with how it goes.
For me, no. My wife has always loved to drive, so I'm already experiencing lots of driving as a passenger, including while commuting (we work near each other). I agree it's often more convenient than driving myself, but I, the passenger, have always worked hard to make sure we have the shortest commute possible.
You might look at studies of people's attitude toward commuting. My memory of those results is that they find that on net people hate commuting and they never stop hating it. I don't remember there being a special exemption for people who are passengers, but maybe some of the literature studies it specifically.
The question, of course, is whether enough people love sitting in a car that traffic becomes traffickier, but your vision, if I understand it correctly, assumes a widespread enthusiasm for auto transport that I believe we already know is not there.
Happy to be proven wrong here, but that seems like a fairly extraordinary claim. Do you have any evidence that latent demand for transportation being essentially unlimited?
Well every time we have reduced the cost of transport so far, the amount of transport we have done has gone up enormously.
Yeah, seems nuts to me. (See my comment above)
I like the story, but I'd be interested in actually calculating the tradeoff between slowing adoption vs preventing gridlock.
Globally, 1.2 million traffic deaths per year is a current, tangible problem that self driving cars can address. Omnigridlock is a theroetical future problem that they MIGHT cause.
If we look at the math: 1.2 million traffic deaths per year x 80% reduction via self-driving cars, then that would mean ~950k deaths annually prevented.
If a preemptive congestion tax delays mass adoption by just an average of 3 months, that equates to roughly 240,000 lives lost compared to the counterfactual of delaying taxes until congestion becomes a real problem.
Yes, good cost benefit analysis, and good reminder to always start with the cost benefit analysis so as not to get lost in the weeds that are the wrong arguments.
Worth adding that AV safely will probably go the way airline safety has gone, where industry works to continue to reduce road deaths until they're down by much more than 80%.
Or we could develop an actual mass transit system and incentivize its use....
I mean, we could do both? But if you look at the trends, one of them is happening (self driving cars) and one of them is not happening (mass transit, in America at least). And even outside of America, there are still a lot of deaths from cars in places with good public transit so... please come back to this reality lol
1. great story and examples with the aquifer, passenger pigeon, etc.
2. how do you know how many miles an AV drives and thus charge them per mile?
3. if you're taxing AV use, how much will that slow adoption? the common wisdom applies: "if you want less of something, tax it."
Seems like an alternative to just taxing AVs at higher rates would be to lean into lane tolls. One lane/rate for someone drinking beers and happy to go 10 miles an hour; another lane/rate for the commuter rushing to a meeting; another lane for emergency vehicles; etc.
Speeding the adoption of AVs saves lives! So we should be extra cautious of imposing policies that would slow down what will already be a difficult transition
I don't think we should charge them per mile necessarily. I think we should 'surge price' for congestion only. I agree it's a tradeoff against slowing adoption, but I won't let that imperfection be the enemy of the good.
Agreed, my point is that there are more alternatives to consider. And solutions that could be less imperfect.
I don't know where you get the idea that the demand for transport is unlimited. My personal demand for transport is very limited, and I suspect that I'm not much different than a lot of others. With more people working from home, conferences and meetings being held online, and ever more people shopping online, I wouldn't be surprised if transport demand goes down; not up.
There may very well be less cars on the road when self-driving cars are widely available, because many people won't even need to buy a car - why lay out large amounts of capital, $40,000 and up, and pay for maintenance and insurance, if you can just have a robo pick you up and drop you off?
Good point. Not owning a car means each taxi ride is an incremental purchase, which I guess disincentivizes trips.
I don't agree with the premise of unlimited demand. Traffic demand is driven by population and the distance you need to travel. The people stuck in gridlock right now aren't going to walk an hour to work in bad weather. They will stay in the gridlock.
As you said, "When self-driving cars become 90 percent of the cars on the road, they will be able to platoon and join up into little trains, saving the space usually spent on gaps between vehicles and doubling road capacities."
Waymo will increase road supply, but I don't foresee that being massively outpaced by road demand.
Waymo claims avoid making traffic worse by what they call 'slow and steady driving' and that their cars do drive in a way that avoids making traffic worse. I've heard the first part many times before, and the second part does seem like exactly the sort of thing that an automated driving system would be good at. I'm no expert, but it sounds like this may be another source of reduced traffic when more AVs are present.
Wow this is the most disappointingly car-brained thing I've read in WiP.
Yeah maybe it's a good thing that AV's will create massive gridlock: This will then incentive the use and development of a system which *can't* get gridlocked and can carry more capacity than any "Waymo train" ever could : That is, an actual mass transit system with actual trains.
This seems correct to me, but I wonder if we can't set some threshold level of (individual) use where by below this level the use of autonomous vehicles isn't taxed. This would seem to help avoid regressive effects, including (or especially) the regressive effect of non-autonomous vehicles being cheaper by comparison.
We've already experimented in London. Licencing Uber in 2012 saw PHVs rise from 45,000 to over 90,000. noticeably adding to congestion in central and inner London.
Note that prior to 2025 most Uber drivers used hybrid vehicles that were exempt from the congestion charge.
I imagine that, as with Uber, lobbying will decide what happens