7 ms·

30 people in 30 waymos vs 30 people in an electric bus? No contest.

by realo 26d ago

xnx 26d ago
No contest when the bus is full, but the overall efficiency (/"greeness") of the system is much less clear considering: buses are rarely full, most buses are diesel, heavy buses tear up the pavement on their routes (especially near stops), and buses don't take riders directly to/from their destinations.
- laurencerowe 26d ago
  Most of the city buses in my UK home town are now battery electric double deckers. These carry up to 85-90 people (with 25 standing), weigh 11 tonnes, and is 10.5m long. A typical jaguar Waymo usually carries up to 4 people (usually just one), weighs 2.1 tonnes and is 5.2m long. So the double decker bus should be more environmentally efficient with maybe 5 passengers making independent journeys, though operational costs for paying a driver probably make the Waymo more financially efficient in that situation. I suspect robotaxis will become very important in suburban areas with distributed jobs where buses don’t work well. In busy cities there simply isn’t the roadspace to replace buses with robotaxis (or any other form of car) for commuting.
  - cyberax 26d ago
    > A typical jaguar Waymo usually carries up to 4 people (usually just one), weighs 2.1 tonnes and is 5.2m long. A more reasonable taxi for single riders is going to weigh around 1.5 tons (e.g. the prototype Tesla Robocab). You also incorrectly assume that the efficiency depends linearly on weight. It doesn't, it depends more on aerodynamics, speed, and the number of stops. London buses (11 tons) average around 2.2 kWh/mi, Tesla Model 3 is at 0.21 kWh/mi while weighing 1.8 tons.
  - hackingonempty 26d ago
    Road damage scales hypercubically with axle weight, so an 11 ton 2-axle bus does ~1400 times more damage to the road than a 1.8 ton Tesla. https://en.wikipedia.org/wiki/4th_power_law https://en.wikipedia.org/wiki/4th_power_law
  - xnx 25d ago
    This is the right way to think about it. Larger buses make sense when there are a lot of people going to and from the same places at the same time, but I think that is much more rare in my city after remote work became widespread.
  - fragmede 25d ago
    The real question is what's the optimal size for a bus if you don't have to pay a human to drive it? Once the technology is proven, there's no reason you can't put the Waymo or other self-driving technology in a bus. A bus designed for a dozen people instead of 30, and a fleet of them that did point to point rides instead of a fixed route, just all booked via the app so you share rides with other people. I dare say that would be the best of both worlds.
    - laurencerowe 25d ago
      > The real question is what's the optimal size for a bus if you don't have to pay a human to drive it? It will depend on the area. Where I am in San Francisco we have articulated buses designed for 100+ people running every few minutes above BART. (We probably need more BART stations.) There’s simply not enough road space for smaller buses (let alone cars) to carry commuter traffic downtown. (I’ve never worked downtown though so always drove to work in desolate Silicon Valley office parks.) Even in my smaller UK home city (250k people) you need double decker 70+ capacity buses running every 15 minutes on two routes from city centre to university to handle demand because the jobs are not so distributed.
phoghed 26d ago
Different 30 people in the US. I’d drop my car if Waymo was around and financially made sense. You’ll never catch me wasting my time on a bus though. We’ll never even be close to Europe or elsewhere wrt where public transit was even decades ago in those places. People here only ride the bus when there’s no other option for them. Waymo could make a bus too anyway, especially after they’ve been in an area a while and have data about where they’d have the most impact. Internet at large would probably decry it as enshittification.
- malnourish 26d ago
  Bus was just fine in Portland, Seattle, and San Francisco.
  - rootusrootus 26d ago
    > Bus was just fine in Portland Yes, if you live within about 1 mile of downtown and also work there. If you live downtown and your job is in Beaverton, you're likely in for a 90 minute commute. Or if you live in Beaverton and your office is downtown. Portland's mass transit is adequate for a subset of people and completely impractical for most. Source: I've lived in and around Portland for 50 years. Worked downtown much of it, and have lots of friends and former colleagues who used public transit. You have to really want to not have a car because the time commitment is real.
    - derektank 26d ago
      Okay, but clearly there’s a difference between, “the bus makes sense if you live or work near downtown,” and, “people only ride the bus when there is no other option,” as the GP said.
      - phoghed 25d ago
        Yeah theres a couple spots that it’s fine for people that have never experienced what’s actually possible.
    - 25d ago
cyberax 26d ago
An average bus load in the US is around 18 people. So if you just compute the raw bus emissions, then an electric bus is maybe about 2x more efficient than personal EVs. But wait, there's so much more! A single bus/subway ride costs about $20, which is a surprisingly consistent figure for various US cities. In NYC it's $17, for example. I'm talking about the _true_ cost, as in: "yearly operational budget divided by the number of trips". And most of this cost comes from 3-4 drivers that every bus needs, not from the hardware itself. Price is a pretty reliable proxy for CO2 emissions for general market goods and services. And with these kinds of numbers, personal cars are competitive. Even if we factor in subsidized road maintenance cost ( https://taxfoundation.org/data/all/state/state-infrastructure-spending/ https://taxfoundation.org/data/all/state/state-infrastructur... ). If we now add mild carpooling, so that a single robotaxi drives 2-3 people, then classic transit just dies. It's like comparing horse-drawn carriages with steam trains.
- deleted 26d ago
  [deleted]
- NicuCalcea 26d ago
  Most of the cost comes from paying the drivers, but also cost is a proxy for emmissions?
  - cyberax 26d ago
    Yes? Why is this strange? Drivers emit a lot of CO2, just like every person in the US. A driverless car allows these emissions to be reallocated to other more productive areas.
    - NicuCalcea 25d ago
      You're counting emissions from a person's breathing as part of the vehicle's emissions?
      - xnx 25d ago
        People take their salaries and buy food, clothes, heating and air conditioning, cars and fuel, and plane tickets, and furniture. All of those things generate emissions in their production and/or transportation. This is why dollars is such a good proxy for co2 emissions.
tjwebbnorfolk 26d ago
Maybe it's different where you live, but 95% of the buses I see driving around here are completely empty.
- fwip 26d ago
  Are you near the city center, or out near the suburbs? It's common for a bus to be crowded on one part of the route and nearly empty at the end.
  - cyberax 26d ago
    And this is a fundamental issue with transit. It _has_ to travel as mostly empty on avereage to be useful.
    - fragmede 25d ago
      ...no? In the heart of downtown, with people riding in both directions, I don't see how it follows that it has to mostly empty to be useful. If it's full you can't get on so that's not useful, but anything less than totally full should still be useful.
      - tjwebbnorfolk 24d ago
        Because most of the mileage is not burned downtown, it's burned by having a bunch of empty buses drive way out of town and pick up in 0 or 1 or 2 people until it fills up right near the center.
        fwip 23d ago
        If you look at average ridership over time, you'll see that the times when it has 40-60 people on it give an average passenger density much higher than cars, even after averaging in the longer empty miles. (40 passengers is a pretty comfortable, not crowded bus.) Simplifying, but a mile of 40 people, averaged with 10 miles of 1 person, is still an average of 5 people. And those are deliberately bad numbers. As I understand it, average bus occupancy in Seattle is around 10 or 15 people per bus, during non-commuting hours. (Commute is often quite crowded).

30 people in 30 waymos vs 30 people in an electric bus? No contest.

by realo 26d ago

30 people in 30 waymos vs 30 people in an electric bus? No contest.

xnx 26d ago

No contest when the bus is full, but the overall efficiency (/"greeness") of the system is much less clear considering: buses are rarely full, most buses are diesel, heavy buses tear up the pavement on their routes (especially near stops), and buses don't take riders directly to/from their destinations.

laurencerowe 26d ago
Most of the city buses in my UK home town are now battery electric double deckers. These carry up to 85-90 people (with 25 standing), weigh 11 tonnes, and is 10.5m long. A typical jaguar Waymo usually carries up to 4 people (usually just one), weighs 2.1 tonnes and is 5.2m long. So the double decker bus should be more environmentally efficient with maybe 5 passengers making independent journeys, though operational costs for paying a driver probably make the Waymo more financially efficient in that situation. I suspect robotaxis will become very important in suburban areas with distributed jobs where buses don’t work well. In busy cities there simply isn’t the roadspace to replace buses with robotaxis (or any other form of car) for commuting.
- cyberax 26d ago
  > A typical jaguar Waymo usually carries up to 4 people (usually just one), weighs 2.1 tonnes and is 5.2m long. A more reasonable taxi for single riders is going to weigh around 1.5 tons (e.g. the prototype Tesla Robocab). You also incorrectly assume that the efficiency depends linearly on weight. It doesn't, it depends more on aerodynamics, speed, and the number of stops. London buses (11 tons) average around 2.2 kWh/mi, Tesla Model 3 is at 0.21 kWh/mi while weighing 1.8 tons.
- hackingonempty 26d ago
  Road damage scales hypercubically with axle weight, so an 11 ton 2-axle bus does ~1400 times more damage to the road than a 1.8 ton Tesla. https://en.wikipedia.org/wiki/4th_power_law https://en.wikipedia.org/wiki/4th_power_law
- xnx 25d ago
  This is the right way to think about it. Larger buses make sense when there are a lot of people going to and from the same places at the same time, but I think that is much more rare in my city after remote work became widespread.
- fragmede 25d ago
  The real question is what's the optimal size for a bus if you don't have to pay a human to drive it? Once the technology is proven, there's no reason you can't put the Waymo or other self-driving technology in a bus. A bus designed for a dozen people instead of 30, and a fleet of them that did point to point rides instead of a fixed route, just all booked via the app so you share rides with other people. I dare say that would be the best of both worlds.
  - laurencerowe 25d ago
    > The real question is what's the optimal size for a bus if you don't have to pay a human to drive it? It will depend on the area. Where I am in San Francisco we have articulated buses designed for 100+ people running every few minutes above BART. (We probably need more BART stations.) There’s simply not enough road space for smaller buses (let alone cars) to carry commuter traffic downtown. (I’ve never worked downtown though so always drove to work in desolate Silicon Valley office parks.) Even in my smaller UK home city (250k people) you need double decker 70+ capacity buses running every 15 minutes on two routes from city centre to university to handle demand because the jobs are not so distributed.

phoghed 26d ago

Different 30 people in the US. I’d drop my car if Waymo was around and financially made sense. You’ll never catch me wasting my time on a bus though. We’ll never even be close to Europe or elsewhere wrt where public transit was even decades ago in those places. People here only ride the bus when there’s no other option for them. Waymo could make a bus too anyway, especially after they’ve been in an area a while and have data about where they’d have the most impact. Internet at large would probably decry it as enshittification.

malnourish 26d ago
Bus was just fine in Portland, Seattle, and San Francisco.
- rootusrootus 26d ago
  > Bus was just fine in Portland Yes, if you live within about 1 mile of downtown and also work there. If you live downtown and your job is in Beaverton, you're likely in for a 90 minute commute. Or if you live in Beaverton and your office is downtown. Portland's mass transit is adequate for a subset of people and completely impractical for most. Source: I've lived in and around Portland for 50 years. Worked downtown much of it, and have lots of friends and former colleagues who used public transit. You have to really want to not have a car because the time commitment is real.
  - derektank 26d ago
    Okay, but clearly there’s a difference between, “the bus makes sense if you live or work near downtown,” and, “people only ride the bus when there is no other option,” as the GP said.
    - phoghed 25d ago
      Yeah theres a couple spots that it’s fine for people that have never experienced what’s actually possible.
  - 25d ago

cyberax 26d ago

An average bus load in the US is around 18 people. So if you just compute the raw bus emissions, then an electric bus is maybe about 2x more efficient than personal EVs. But wait, there's so much more! A single bus/subway ride costs about $20, which is a surprisingly consistent figure for various US cities. In NYC it's $17, for example. I'm talking about the _true_ cost, as in: "yearly operational budget divided by the number of trips". And most of this cost comes from 3-4 drivers that every bus needs, not from the hardware itself. Price is a pretty reliable proxy for CO2 emissions for general market goods and services. And with these kinds of numbers, personal cars are competitive. Even if we factor in subsidized road maintenance cost ( https://taxfoundation.org/data/all/state/state-infrastructure-spending/ https://taxfoundation.org/data/all/state/state-infrastructur... ). If we now add mild carpooling, so that a single robotaxi drives 2-3 people, then classic transit just dies. It's like comparing horse-drawn carriages with steam trains.

deleted 26d ago
[deleted]
NicuCalcea 26d ago
Most of the cost comes from paying the drivers, but also cost is a proxy for emmissions?
- cyberax 26d ago
  Yes? Why is this strange? Drivers emit a lot of CO2, just like every person in the US. A driverless car allows these emissions to be reallocated to other more productive areas.
  - NicuCalcea 25d ago
    You're counting emissions from a person's breathing as part of the vehicle's emissions?
    - xnx 25d ago
      People take their salaries and buy food, clothes, heating and air conditioning, cars and fuel, and plane tickets, and furniture. All of those things generate emissions in their production and/or transportation. This is why dollars is such a good proxy for co2 emissions.

tjwebbnorfolk 26d ago

Maybe it's different where you live, but 95% of the buses I see driving around here are completely empty.

fwip 26d ago
Are you near the city center, or out near the suburbs? It's common for a bus to be crowded on one part of the route and nearly empty at the end.
- cyberax 26d ago
  And this is a fundamental issue with transit. It _has_ to travel as mostly empty on avereage to be useful.
  - fragmede 25d ago
    ...no? In the heart of downtown, with people riding in both directions, I don't see how it follows that it has to mostly empty to be useful. If it's full you can't get on so that's not useful, but anything less than totally full should still be useful.
    - tjwebbnorfolk 24d ago
      Because most of the mileage is not burned downtown, it's burned by having a bunch of empty buses drive way out of town and pick up in 0 or 1 or 2 people until it fills up right near the center.
      - fwip 23d ago
        If you look at average ridership over time, you'll see that the times when it has 40-60 people on it give an average passenger density much higher than cars, even after averaging in the longer empty miles. (40 passengers is a pretty comfortable, not crowded bus.) Simplifying, but a mile of 40 people, averaged with 10 miles of 1 person, is still an average of 5 people. And those are deliberately bad numbers. As I understand it, average bus occupancy in Seattle is around 10 or 15 people per bus, during non-commuting hours. (Commute is often quite crowded).