5 ms·

We don't need a 4000 lb vehicle to move a ~200 lb person. In order of efficiency: (1) Walk (2) Unicycle, roller skate, scooter (no battery, very little mater

• LUmBULtERA 3y ago
  Is taking an ebike really that efficient if its going to be stolen? I kid.. because I have one. But I take 3 locks with me when I need to leave it unattended...
  • ryukafalz 3y ago
    I do worry about this some, but I also have my bikes insured including an e-cargo bike. Cheaper than most car insurance. Still would be a pain in the ass if my bike got stolen though.
    • em500 3y ago
      In the Netherlands many insurance companies have stopped offering insurance for ebikes and electric cargo bikes, because the chance of theft is too high (approaching 90% in Amsterdam on certain types according the insurance companies).
• Shatnerz 3y ago
  How are you defining efficiency here? Is walking really more efficient than cycling? I would put walking as the least efficient manual powered methods mentioned. Aside: I used to unicycle to work, and I have to say that it was both fantastic and much faster than walking while on a 27.5" wheel.
  • Sharlin 3y ago
    Walking is probably the most efficient from a (public) health viewpoint. Given that the major problem in the West is lack of physical activity and excess calorie input.
    • bootwoot 3y ago
      Which is to say, the least efficient
  • supermatt 3y ago
    Yup, IIRC in terms of kJ/km cycling is ~4x more efficient than walking (on flat surface). I guess they must be talking about the energy used in production, etc.
    • baxuz 3y ago
      It's closer to 6x.
      • nordsieck 3y ago
        I mean, the number will really depend on how fast people are biking. Over 20mph, efficiency starts to really take a hit. Unless you use some sort of crazy shell.
        • gpm 3y ago
          Cycling anywhere near 20mph is beyond most peoples physical capabilities... with the small exception of steep downhills where the energy is "free" (at least compared with walking where you capture none of it) anyways.
• pyrophane 3y ago
  I wonder how this ranking might change if we also took into account the energy required to produce the extra calories that humans need to consume in order to get around via these modes of transportation. Like, you'd probably expend a lot of calories traveling 10 miles by unicycle, and over time maybe that would be more significant than the materials difference compared to cycling? Of course, it depends a lot on the diet of the human in question.
  • flavius29663 3y ago
    Most humans on earth already eat way more than what they need. Exercising might actually make them eat less in the long run, because they'll lose weight and not eat so much anymore.
  • dgacmu 3y ago
    There's a secondary cost savings in reduced health care costs from the extra exercise. (May not apply in all countries, but does for the US/Europe).
• agent281 3y ago
  At least part of what keeps people from switching to more eco-friendly transportation is the protection arms race: people buy bigger cars because they are safer for their occupants. This leads to more injuries because bigger cars do more damage. Which means people are more concerned about injuries and buy bigger cars. This is one area where I am concerned about the impacts of electric vehicles. They weigh a lot more than ICE cars and might cause more significant injuries for pedestrians. There probably ought to be some sort of tax or fee on vehicles that scales by weight. However, that would favor ICE vehicles over EVs so it may not be popular among the people who might otherwise be interested in such things.
  • pcl 3y ago
    IANA automotive engineer, but I would assume that injuries from car-vs-pedestrian collisions are mostly due to impact velocity, and not due to momentum. I wouldn’t be surprised if the higher-mass electric vehicles are more dangerous to other cars when involved in car-vs-car collisions, though.
    • bluGill 3y ago
      Smaller cars are more likely to throw you up and over - still dangerous, but not as dangerous as a direct inelastic hit. Smaller cars have better visibility of pedestrians and so are more likely to see and thus avoid pedestrians. If you take a direct hit with even a tiny car at faster than 30mph you are dead. However smaller cars make it somewhat less likely you take that direct hit.
      • pcl 3y ago
        Yeah — but when I hear people talking about how EVs are heavier, I assume that people are making a like-for-like model comparison. In a similar body size, EVs tend to weigh more, due to all the extra battery.
    • agent281 3y ago
      IANA automotive engineer either. I'll quote national bureau of economic research: > The probability of a fatality, conditional on a collision, is 0.19 percent -- or about one in five hundred. The authors find that being hit by a 1,000-pound heavier vehicle results in a 47 percent increase in the baseline probability of being killed in the accident... https://www.nber.org/digest/nov11/vehicle-weight-and-automotive-fatalities https://www.nber.org/digest/nov11/vehicle-weight-and-automot....
• ashton314 3y ago
  I would be delighted to ride a zip line to work
• baryphonic 3y ago
  Energy efficiency is not the only variable that matters. Walking to my grocery store would take almost two hours each way. Biking would take 30 minutes each direction. Driving is 14 minutes each way, and is the only feasible way I can get groceries when I have my kids in tow (which sometimes is a necessity).
  • stetrain 3y ago
    Of course. If in the big picture we want fewer people to need to take a car for each trip, it would be a good idea to have towns and cities where grocery stores and houses are closer together. And of course not everyone wants to live in such a place, but plenty of people would. And in the US this is fairly rare compared to many other parts of the world.
    • raffraffraff 3y ago
      Who wouldn't want to live close to the grocery store? Here in Dublin I live in a house with gardens front and back, 5km from the center of the city, with a grassy park in front of my house (football field size), yet I can walk to 4 different supermarkets. The furthest is about 15m walk, the nearest is 10m. And I've got a few small convenience shops even closer (like, under 5m walk). This is what I call "perfect", and I don't understand why someone wouldn't want this. Unfortunately they stopped building communities like this in the 1950s, but they sprawl for miles around Dublin, and I consider myself lucky to be able to live here. I've visited cities in the Midwest of the US and found them to be like hell. Can't walk anywhere.
      • stetrain 3y ago
        Oh I would definitely prefer it. I think a lot of people would. So many Americans haven't lived that life though that it can be hard to imagine.
  • dublinben 3y ago
    How inefficient is it that your grocery store is 5 miles away? Everyone should have a grocery store within a 5 minute walk of where they live.
• ReactiveJelly 3y ago
  tbf I prefer to measure human loss in QALYs in case a disease mostly kills old people. It's impossible to measure perfectly but it's not worse than "A death". We all die in the end.
• aftbit 3y ago
  Certainly in the Bay it's pretty easy to get by with no car at all - just rent or borrow one if you want to take a trip to Tahoe every once in a while. If you go deeper into the country though, there are many places where car ownership is nearly mandatory, especially for people who can't WFH. EVs are pretty close to being able to replace ICE cars around here, but still can't match the range, cost, or longevity of an ICE vehicle. I could do 80%+ of my miles in an EV, but once or twice a year, we take a 1000 mile road trip that would be considerably more painful in an EV. If we're only going to own one car, it still needs to be ICE. That said, I do own two cars. One of them is a 2001 Ford truck that is on its last legs. It's not very environmentally friendly to run, but given that I put so few miles on it per year, it's probably better than causing a new car to be produced, regardless of its technology. Would I still be able to run a 2023 EV in 2044? Will the batteries last that long, with any sort of usable range?
  • woodruffw 3y ago
    > If you go deeper into the country though, there are many places where car ownership is nearly mandatory, especially for people who can't WFH. This is true, but it's also worth noting that it's true because small and medium-sized cities systematically dismantled their public transportation systems between the 1920s and 1960s, replacing them with infrequent bus services. One of the things I do when trying to understand how so many of our smaller cities became car hells is to Google "$CITY streetcars 20th century." We had the infrastructure and chose to remove it.
    • aftbit 3y ago
      Yes, my city is one of those. Sadly it leads to a death spiral. The bus sucks, so nobody rides it, so the bus gets no money, so they cut routes, so the bus sucks more, so fewer people ride it.......
  • shortcake27 3y ago
    > but once or twice a year, we take a 1000 mile road trip that would be considerably more painful in an EV. If we're only going to own one car, it still needs to be ICE. You could just rent a car for those two trips like you suggested yourself in your first paragraph ;). Optimise for the most common scenario, not the least common one. > Would I still be able to run a 2023 EV in 2044? Will the batteries last that long, with any sort of usable range? Replacing the battery pack on an EV once every 15 years is certainly cheaper than all the maintenance that goes into an ICE in the same timeframe. Hopefully we can start recycling batteries properly before the current generation of EVs is up for battery replacements.
• henry_viii 3y ago
  > a 4000 lb vehicle Amateur numbers. The F-150 Lightning is 6,500 lb (2,950 kg) and the Rivian trucks (R1T, R1S) are 7,000 lb (3,175 kg). The electric F-150 is 35% heavier than the ICE model. Meanwhile: https://news.ycombinator.com/item?id=37726539 https://news.ycombinator.com/item?id=37726539
• schaefer 3y ago
  not to get us too far off track, but unicycling is WAY less efficient than walking. For those that have never tried it: it's like trying to go for a jog while maintaining a three-quarters-squat posture.
  • generalizations 3y ago
    I’m disappointed they weren’t talking about electric unicycles…I have one of those, and it just feels like skiing. No real effort required.
• ackfoobar 3y ago
  Many aspects to the word "efficiency". Space efficiency - how wide it takes to reach a certain throughput - train wins Time efficiency - how much time it takes to get from point A to point B - barring traffic, car wins Energy efficiency - how much energy it takes - bike wins Your argument is just as strong without the subjective ranking of efficiency.
  • soperj 3y ago
    Majority of my time commuting the bike wins every time, mostly because I'm commuting at the same time as everyone else.
    • slothtrop 3y ago
      Good for you. Doesn't describe everyone else.
    • q1w2 3y ago
      Not an option any more when you need to start dropping kids off at school first - not to mention the weather and safety.
      • soperj 3y ago
        I drop my kids off at school on the way. They bike too. Started with a trail-a-bike, and now they are their own bikes and I bike with them to school on my way.
        • q1w2 3y ago
          I bet you live in a different climate than me. ...and your kids are likely older. These factors matter dramatically.
      • papa-whisky 3y ago
        There are tons of options for carrying kids on a bike. Made even easier when you add electric assist.
• rootusrootus 3y ago
  > (5) Mass transit (can be public/private) transportation: Electric trains This depends quite a lot on ridership. E.g. a typical MAX train in Portland, filled at perhaps 10% capacity aside from a few narrow time periods in the morning and evening, loses out on efficiency to a Honda Civic with four people. Trains are heavy even when they are empty.
  • atom058 3y ago
    But most cars are not filled with 4 people: quite often it's only one or two And many don't drive a Honda civic: they are driving the biggest, heaviest car they can get their hands on
• slothtrop 3y ago
  > We don't need Let me stop you right there. We "don't need" most of the possessions you currently own, including the one you're using to browse HN. We don't live for mere subsistence. People can decide for themselves what they want to give up to reduce their carbon footprint, and that doesn't necessarily have to be their vehicle.
• mnw21cam 3y ago
  If you're defining efficiency as energy required to travel a distance, then an electric bike that doesn't require effort from the rider is going to be way more efficient than walking or cycling. That was one of the exercises I had when studying - calculate the energy intensity of various modes of transport. It turns out that if you calculate the whole energy requirements to get the extra food into someone's mouth that they'll want if they are walking or biking, then it's not much different to the amount of energy that would be used by just driving a car. Making food is energy-intensive, and the conversion efficiency into mechanical output by a working person is very low. In contrast, an electric motor and a battery can both be made extremely efficient.
  • tomjakubowski 3y ago
    Would you show your work? I am curious and a little bit skeptical. A gallon of gasoline has about 31,000 kcal. In the US, a typical sedan gets about 30 miles per gallon. Walking a mile at 150lb bodyweight burns about 100 kcal. (This is non linear though: walking longer distances will burn less per mile on average) If we assume linearity, to walk an extra 30 miles in a day you'd need 3000 more kcal of food. What is the energy cost of growing and transporting 3000 kcal of food? Does it exceed 31,000 kcal?
    • mnw21cam 3y ago
      This was 10-15 years ago, so I don't have my notes lying around. However, I do remember that it was based on the calorific efficiency of bread bought at a supermarket. Other foods may vary - for instance if you grow potatoes in your back garden then it's probably going to be a lot more efficient. I can well believe that there is a 10:1 ratio between energy in and mechanical energy out of a human. However my point wasn't that cars and humans are about the same. That's probably only true in the "same order of magnitude" sense. My point was that humans are way less efficient at propelling a bicycle than an electric motor is.