Check out the episode:
You can find the shownotes through this link.
Are you interested in the impacts of autonomous vehicles on the urban fabric?
Our debate today works with the article titled Impacts of connected and autonomous vehicles on urban transportation and environment: A comprehensive review from 2023, by Md. Mokhlesur Rahman and Jean-Claude Thill, published in the Sustainable Cities and Society journal.
This is a great preparation to our next interview with Cormac McKay in episode 414 talking about the opportunities with autonomous vehicles.
Since we are investigating the future of cities, I thought it would be interesting to see the SWOT analysis of autonomous vehicles for the future of cities. This article investigates the short, medium, and long-term impacts of connected and autonomous vehicles on urban transportation, the environment, and city planning.
[intro music]
Welcome to today’s What is The Future For Cities podcast and its Research episode; my name is Fanni, and today we will introduce a research by summarising it. The episode really is just a short summary of the original investigation, and, in case it is interesting enough, I would encourage everyone to check out the whole documentation. This conversation was produced and generated with Notebook LM as two hosts dissecting the whole research.
[music]
Speaker 1: When urban planners look at a city. They often see it as a living biological organism
Speaker 2: with roads as the arteries.
Speaker 1: Exactly. Roads are the arteries and vehicles are the blood cells, keeping the whole system alive. But right now, if we look at modern cities, those arteries are severely clogged. We have massive traffic, heavy pollution, and just spatial gridlock.
Speaker 2: Yeah, a complete systematic blockage.
Speaker 1: It really is. So imagine if we could introduce intelligent, highly coordinated cells into that bloodstream to clear the blockages and optimize the flow entirely. That is the promise of the autonomous vehicle.
Speaker 2: It is a beautiful vision. I’ll give you that, but we have to ask, what if those automated cells operate so effortlessly that the organism simply stretches itself out? What if the city expands endlessly until its vital organs? The downtown centres just wither away.
Speaker 1: That tension is exactly what we are dissecting today. Will the widespread adoption of autonomous vehicles ultimately lead to highly efficient, sustainable, dense urban environments, or will they trigger a new era of urban sprawl, increased traffic demand, and energy strain.
Speaker 2: And to get to the bottom of this, we are looking at a comprehensive review published in Sustainable Cities and Society. The researchers synthesized over a hundred recent studies that modelled the short, medium, and long-term effects of AVs on urban forms and transportation networks.
Speaker 1: I will represent the perspective that autonomous vehicles particularly shared autonomous electric vehicles, will serve as a catalyst for urban efficiency. Dramatically slashing vehicle ownership, parking demand, and greenhouse gas emissions.
Speaker 2: And I will argue that AVS will actually induce massive travel demand, generate dangerous levels of empty vehicle miles, accelerate urban sprawl by making long commutes effortless, and threaten our existing public transit systems.
Speaker 1: Let’s start by picturing exactly how this optimized mobility works on a mechanical level. When we transition to shared autonomous vehicles or SAVs, the efficiency gains are staggering. Data shows a single SAV can serve 31 to 41 passengers a day,
Speaker 2: which is a huge jump from private cars,
Speaker 1: massive because it is electric and fast charging, it’s almost always in motion. The models project that just one long range fast charging SAV could replace up to 11.5 private vehicles.
Speaker 2: I hear the theoretical efficiency there, but we have to look at how humans actually behave.
Speaker 1: Just to finish the thought on the cadex, because it’s vital, this shift virtually eliminates the need for vast parking infrastructure. If cars are always moving, we are talking about reducing parking demand by up to 90% plus by using cooperative adaptive cruise control and vehicle to everything communication. We eliminate, stop and go traffic. It’s a true mathematical optimization of the physical world.
Speaker 2: I come at it from a completely different angle. You are describing a flawless mechanical optimization, but you are ignoring behavioural economics. When the opportunity cost of driving drops, human behaviour changes. Think about it. If you can now work on your laptop, take a nap, or watch a movie in your car, the pain of a long commute completely disappears. Fundamental economics tells us that when something costs less, less time, less stress, people consume more of it. So the literature strongly suggests overall vehicle miles travelled or VMT is expected to increase by five to 25%, and the most critical flaw in the system is empty. VMT
Speaker 1: You mean the ghost vehicles?
Speaker 2: Exactly. Ghost vehicles. These are zero occupancy cars roaming the streets empty between fares or worse, circling the block continuously because driving in circles is cheaper than paying for downtown parking. They threaten to increase overall congestion, not relieve it.
Speaker 1: That’s a fascinating way to look at it, but let me give you a different perspective. Yes, the overall miles travelled might increase, but that has to be weighed against the sheer reduction in physical cars on the road,
Speaker 2: but a car is still a car taking up space.
Speaker 1: Sure. The review highlights a projection that the US fleet could drop from 247 million down to just 44 million vehicles by 2030. That is a massive reduction in the physical footprint.
Speaker 2: Only 44 million.
Speaker 1: Yes, down to 44 million. And even if those remaining vehicles are driving more miles, the optimization of trip chaining. An algorithm perfectly, links, pickups, and drop-offs is projected to reduce total travel time by up to 78% in a hundred percent AV penetration scenario,
Speaker 2: I’m sorry, but I just don’t buy that. A smaller fleet inherently solves a problem. Fewer cars does not automatically mean less traffic if those fewer cars are moving constantly. A parked car doesn’t cause a traffic jam. A moving car does
Speaker 1: well. A parked car takes up valuable space, though.
Speaker 2: True. The models specifically show that SAVs could generate 19.6 to 31.5% more vacant empty V empty if you shrink the fleet, but suddenly a third of your downtown traffic consists of empty pods driving around. You haven’t solved traffic. You’ve just automated the traffic jam.
Speaker 1: I see why empty miles sound terrifying if handled poorly, but doesn’t dynamic ride sharing fundamentally neutralize this, combining trips with similar routes. If you and a neighbour are both heading downtown, the algorithm seamlessly puts you in the same vehicle.
Speaker 2: Assuming people wanna share their private pod, sure,
Speaker 1: the data shows they will. If incentivized, a 20 to 30% increase in shared trips actually reduces overall miles travelled by 4.4 miles per shared trip. If we match passengers effectively, that empty VMT problem is heavily mitigated.
Speaker 2: It might be mitigated, but it’s rarely neutralized entirely. Frankly, if you solve that ghost car problem, you create a new one, which is geography. If the way vehicles move changes drastically, the physical city must change with it.
Speaker 1: Yes, the geography will change, but that physical change will be a beautiful reclamation of our cities. Think about how much urban fabric is dedicated to storing metal boxes.
Speaker 2: You’re talking about parking lots.
Speaker 1: Exactly. Right now, 14% of Los Angeles County is used for parking, just parking. Imagine reclaiming that massive amount of land, we can transition dead asphalt into high density housing, active commercial centres, green space.
Speaker 2: Reclaiming 14% of LA is an incredibly beautiful vision, but have you considered the suburban exodus? This technology enables.
Speaker 1: I don’t think an exodus is guaranteed if the City Corps becomes that attractive,
Speaker 2: but the behavioural data points to urban sprawl expanding by 10 to 30% because AVS allow for multitasking. The pain of commuting disappears. In one surveyed scenario in Rome, up to 40% of residents stated they would move out to the suburbs if AV were readily available.
Speaker 1: 40%, that is a high number,
Speaker 2: very high. If your car is essentially a mobile living room, people will gladly trade a cramped apartment for a spacious house 50 miles away. We are looking at polycentric dispersed development that hollows out the city.
Speaker 1: That geographical expansion, if it does happen, is exactly why the integration of the electric powertrain is so vital. SAVs are the ultimate green solution.
Speaker 2: Green, even with endless sprawl.
Speaker 1: Yes, because they communicate instantly. They can draft behind one another inches apart at highway speeds. Platooning. This slashes aerodynamic drag models show greenhouse gas emissions could drop by up to 94% through eco driving platooning and eliminating cold engine starts.
Speaker 2: 94% is an ideal scenario.
Speaker 1: It is, but it’s achievable. Furthermore, we can prevent that urban hollowing by using AVs for robocar oriented development. They solve the last mile problem acting as feeders that pick people up and drop them at train stations. Which actually boosts public transit ridership.
Speaker 2: You are assuming a seamless, perfectly regulated synergy that our infrastructure simply cannot support. Right now, let’s look at the severe vulnerability of the energy grid. There’s a specific calculation from CAM in 2018 that is staggering. If we drop to that highly efficient 44 million vehicle fleet you mentioned, and we charge them just once a day, it would require 3080 gigawatt hours per day. Let’s unpack that number. That is the equivalent of 33 Palo Varde sized nuclear power plants running 24 7.
Speaker 1: That is a massive scale. Absolutely.
Speaker 2: Exactly. And regarding public transit. Without strict regulation, AVS will simply cannibalize efficient transit and active transport, like walking and biking. Why walk in the rain to a subway when a cheap private pod can take you door to door?
Speaker 1: I’m not entirely convinced by that. It assumes we won’t adapt our energy grids or pricing models. The transition to electric infrastructure is happening concurrently. The smart grid will be designed to charge vehicles during off peak hours, maybe even using them as mobile battery storage,
Speaker 2: but that requires a level of policy foresight that historically we just haven’t demonstrated. So to summarize my position, the behavioural risks here are profound, cheaper, easier. Travel is highly likely to induce massive amounts of empty vehicle miles. Drain public transit and push cities into sprawling energy hungry suburbs.
Speaker 1: And from my view, we are stating on the precipice of an unparalleled opportunity. If we get this right, we can reclaim vast swaths of urban space from parking, drastically reduced accidents caused by human error and create a highly efficient fleet.
Speaker 2: I think I will concede one major point where our perspectives converge. The technology itself is essentially neutral.
Speaker 1: Absolutely.
Speaker 2: Whether we achieve utopian efficiency or dystopian sprawl largely depends on policy makers. If we simply allow a one-to-one replacement of human driven cars with private, autonomous cars, the system fails. Success hinges on enforcing shared ownership models and integrating them with public transit.
Speaker 1: I completely agree. The complexity of the material we’ve explored today shows there are so many more technical and socioeconomic limitations to uncover in the research
Speaker 2: returning to where we started, whether these automated cells will clear the arteries of our urban organism or stretch the system until it collapses, the outcome is yet to be determined.
[music]
What is the future for cities podcast?
Episode and transcript generated with Descript assistance (affiliate link).
What is The Future for Cities? Podcast 
Leave a comment