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Comment by smt88 | Hacker News Reader

> Cars are the slowest, lowest-bandwidth forms of urban transportation.

This is the kind of thing I read a lot in micromobility advocacy articles, but it seems like it can't be true. How can a bike, scooter, or moped be either faster or higher-bandwidth than a car?

Also, serious question: if electric SDCs became widespread, would it still make sense to advocate things like bikes?

You can't transport a family of three or a baby as safely in a vehicle smaller than a car (as they lack things like walls and air bags), and the many obese, elderly, and disabled people in the US can't use micromobility easily.

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The key word here is "urban". I ride my bike around the city core sometimes just for fun and I can easily keep up with cars because they are going so slow. Now imagine how many bikes you could fit on a two lane road vs how many cars. Obviously if the car is coming from the suburbs its going to be faster.

> Also, serious question: if electric SDCs became widespread, would it still make sense to advocate things like bikes?

Yes, absolutely yes. The cars would still have to go somewhere after they have dropped off their occupants. Hopefully we will get on-demand carpool services that allow us to have vastly fewer vehicles on the road, which would free up space for bikes and other public transit.

> You can't transport a family of three or a baby as safely in a vehicle smaller than a car

Not everyone can use a bike of course. Some will have to use public transit, and yes some will have to use a car for various reasons. The streets don't have to be car-less, we just need to get enough cars off the road to ease congestion and be able to turn existing lanes into bike lanes or public transit lanes. Once good reliable and quick public transit exists, there won't be such a strong incentive to own a car.

> Now imagine how many bikes you could fit on a two lane road vs how many cars

No need to imagine:

http://lh3.ggpht.com/_9F9_RUESS2E/S7tbclwxiPI/AAAAAAAACmw/uI...

It's a powerful image, but the angle and zoom of the first picture differs a lot from the other two.

I feel the picture is misleading. First, the angle for cars results in a closer, more zoomed in picture than for the bus and bike. Second, it assumes 1 occupant per car, but a full bus. More likely, each car will probably average more than 1 occupant, and buses will probably be less than half full, if not 25%.

I’d be interested in seeing an equivalent side-by-side image based on occupancy data. For instance, cars in the US average only 1.7 people per vehicle:

https://m.wisegeek.com/what-is-the-average-vehicle-occupancy...

Yeah I wish I could find a better picture bit this gives a sense of Edinburgh centre.

https://www.nfpplanning.com/uploads/2/4/0/5/24056719/taxi-tr...

Queues of buses, and during the day they will often only have one or two passenger.

Plus car drivers are advised to give a bike the same room as a car, so on mixed use roads a bike effectively takes up the same space as a car.

> Plus car drivers are advised to give a bike the same room as a car, so on mixed use roads a bike effectively takes up the same space as a car.

Yes, that is one case. On the other hand:

1. The fact that such advices are given doesn't mean they are followed. I also heard that car drivers are supposed to leave at least 1 meter of space between themselves and a bike when overtaking said bike. In my experience that happens only on an empty wide road; otherwise car drivers won't hesitate to overtake as close as possible.

2. In case of bike lanes, bikes obviously do take much less space, both when driving and when queuing.

3. Even in case of mixed road, there may be multiple bikes which do not need to stay so far away from each other.

4. Also on mixed road, when queuing together with cars, bikes will usually position themselves alongside cars, therefore effectively taking zero space in the queue.

5. Finally consider also requirements for parking. A single car parking space could probably fit 10 bikes.

> First, the angle for cars results in a closer, more zoomed in picture than for the bus and bike.

That's true, but I don't think it makes much of a difference. I couldn't fix the angle, but here's the same picture with second and third images also zoomed in similarily: https://imgur.com/a/2GMcSlE

> Second, it assumes 1 occupant per car, but a full bus. More likely, each car will probably average more than 1 occupant, and buses will probably be less than half full, if not 25%.

Actually, below is an example for a few countries. Average number of persons in a car seem to be decreasing with 1.8 in the 80s, down to around 1.4 in 2005. At the same time average seat occupancy for buses seem to be around 70%. This matches what I observe everyday - vast majority of cars has only the driver inside.

https://www.eea.europa.eu/data-and-maps/indicators/occupancy...

These articles are indeed often hyperbolic, and many of your points are fine and neglected by proponents. However, "higher bandwidth" probably refers to the number of people per second that can be transported through a certain lane width. At most speeds cars require roughly 2 seconds minimum between them, and they mostly are single occupancy, so they can't do more than 0.5 persons per second per ~12 foot lane.

Bicycles can do more on account of less spacing front/back and side to side. (This is sort of surprising given that bikes have a slower top speed, but it's really the time-spacing between vehicles, not their top speed, that matters when you're operating at capacity.) Bus can do more on account of being more passengers per vehicle. Trains are denser yet. All these have drawbacks on other metrics, of course.

Cars transport around ~1500 people per hour per lane, while 2 bike lanes taking up the same amount of space of a car lane is ~5200 people per hour. A proper train line does 32'000 people per hour.

https://www.theurbanist.org/2016/05/26/the-supply-and-demand...

A more visual demonstration:

https://humantransit.org/2012/09/the-photo-that-explains-alm...

With one exception that you have to find 5200 people, while cars actually transporting 1500 people and I am not talking about public transport.

From my point of view the top priority should be good public transport.

This may be because I don't live in a "real city" (population 100k, US), but I see people biking with kids all the time (typically in some sort of cargo bike that has had seats added to it). The big threat while biking with kids (or without kids, for that matter) is from cars clipping you as they pass or pulling out in front of you. It's the cars that are the problem, not the bikes. Creating the infrastructure to allow people to bike safely will allow people to do what they're already doing more safely, and it will encourage more people to try it themselves.

IMO the problem is not the car, nor the bike. The problem is that they're sharing the same infrastructure. For new infrastructure I'd suggest also thinking about mopeds and quick electric bikes.

Cars are not space efficient. One person takes up the room of many scooters, bikes or mopeds. The infrastructure that supports cars also takes up incredible amounts of room. They are often slower simply because they are stuck. It is quicker for me to ride my bike 20km than to drive it in my city.

So for space spent on one car to move it and park it in the city you could be moving far more people. If you move to a less car centric CBD, you can still keep some car infrastructure there for people who need a car to get around. But public transport can also be improved, I am willing to bet more mobility challenged people would benefit from that than assuming they all use cars to get around. Not everyone has a carer, or a car that they can utilize.

They are also very inefficient with resources during construction and operation.

Lastly they are the most dangerous to other traffic due to their high mass and high speed.

In cities, bikes are often faster than cars because they just don't get held up by traffic.

In Manhattan or Brooklyn on normal streets my bike goes the same speed as cars when everyone's moving... but I don't suffer any of the bottlenecks. A delivery or moving van or garbage truck might be blocking traffic for two minutes but I go right by. At each red light there might be ten cars stopped but I go straight to the front and cross first when the light turns green. It's significantly faster, in congested Manhattan streets I'd estimate often twice the speed of taking a car/taxi, certainly during rush hour.

And higher-bandwidth if you've ever been to, say, China. When you see 50 cyclists crossing an intersection taking up the space that would fit 5 cars, well it's pretty obvious.

Yup, between being able to move past traffic, occasionally being able to bypass rules of the road (e.g., even if you don't actually bike the wrong way down a one-way, you can still legally walk your bike to the end of the block in less time than it'd take a car to circle), being able to take the subway, and parking, I'm often as fast and occasionally much faster on my bike than a car would be. (My experience is also Manhattan/Brooklyn, though this was often true in SFBA too for short trips.)

When I moved apartments recently, I easily beat my movers' truck via bike-subway-bike from my old place to the nee one because there was some temporary congestion on one of the main roads but the subways were fine.

Most trips are very short. West LA where I live, biking is my fastest commute option (4 miles) because I don't get stuck in traffic.

Pushing people out of cars would probably speed up the cars that are used by reducing the traffic around them. Families can handle more than you'd expect, and I regularly ride the bus with elderly and disabled people, but even if you have someone that needs a car, they don't necessarily need a parking space at each end.

LA is one of the best cities to push cycling - it hardly rains. If the city subsidized electric bicycle uptake it could be a beautiful thing. Of course, you'd had to also make car lobbying illegal so good luck with that.

A lot of micromobility advocates also seem to really hate public transit for whatever reasons, even though it's often superior to cycling in time, safety, and throughput.

To your second question, though, I think the answer is it depends on your intended location and use case. Most micromobility and cycling advocates want changes made to dense urban centers, which are less likely to cater to families with children. SDCs might actually make traffic worse in these places the same way ridesharing has since they will be spending some time driving around empty and also causing congestion when they pick up or drop off passengers. In more suburban settings, though, SDCs make a lot more sense.

> A lot of micromobility advocates also seem to really hate public transit for whatever reasons

I haven't observed this, but it makes zero sense in the US.

The only way you could get 25+ bikes on a road in most of our cities is if they're in a very dense place with great public transit.

Otherwise, average commute distances are going to be too long for most people.

I had no problems transporting my children, even when still a baby, in a cargobike (bakfiets).

It's a pretty convenient way of transporting your children in and out of the city, as it actually gets you to where you need to go. Compare this to a car: you cant really get to the store you need to be, instead you have to park in a parking garage and then carry your baby in the maxi-cosi to the store. I prefer a bike.

> I had no problems transporting my children, even when still a baby

I believe that you and other people do this. I wouldn't do it because I'm afraid of what even a minor cycling accident could do to a child.

Of course I'm coming from a US-centric viewpoint, where bikes share space with cars, pedestrians, and (now) scooters.

> You can't transport a family of three or a baby as safely in a vehicle smaller than a car (as they lack things like walls and air bags)

Most families of three can drive their own vehicles, though. And air bags are really only necessary because of... you guess what.

The "not everyone can ride a bike" argument is vastly overplayed. Not only can almost everyone ride a bike -- but even the ones that can't get a better road environment if fewer people go for the single-occupancy personal automobile as the default. It just occupies so much space that is 99% completely unused.

You don't need air-bags if you don't have cars. You'd also have less obese people if they would ride bicycles. Car is not a solution - it's a cause of problems.

Here is photographic evidence of transporting 3 kids, including a newborn in a childseat, on a bicycle:

https://www.dcrainmaker.com/2019/10/continued-expansion-of-t...

Of course it's the Netherlands, and it is safe to do so when there is infrastructure for it like there.

One reason micromobility has higher bandwidth is that cars typically only have a single occupant, yet occupy the space of perhaps 5 bikes.

That makes sense, but I took the original claim to mean what's possible. So it seems like we're comparing apples-to-oranges:

The reality of cars (single occupant) is lower-bandwidth than the fantasy of bikes (lots of bikes traveling like a school of fish). I agree with that.

But if you compare the reality of both, cars are still massively higher throughput in the US.

And if you compare the fantasy of both (fully-loaded cars vs. herds of bikes), then cars would again be higher-bandwidth.

Yep, if we can get self driving cars and people are actually willing to share that space with strangers it will be a big win for transportation efficiency.

However at the same time we should be investing in density and figuring out ways to make that work. Urban sprawl is massively innefficient by it's nature.

A bike needs maybe five to ten square meters of road space at a speed of 20-30km/h. A car needs around fifteen square meters standing still. Buses and trains are better still.

I’m faster than a car in downtown SF on my jump bike. Even on market I’m even because no one makes a green from one green.

Honestly didn't think I said anything weird. I imagine throughput is high because lots of us can do this. I'm not a hater, I actually have an SUV. I just also ride electric downtown.

I've noticed this too, and that's not counting the time it takes to park. Even some bike routes outside of downtown break even with cars.

Assuming you’re talking about two adults and one kid, two bikes? You can easily transport two kids and an adult with a bike+trailer. Alternatively, in the Netherlands, you see bikes being used as school busses, with 4-6 kids in a big bucket in front, and an adult pedaling it around. You can buy them from various importers elsewhere.

Massive size, huge following distances and lateral gaps, perhaps?

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