[npunt]

The only reason busses are the size they are is the labor cost of the driver only makes sense with many, many passengers. When that is eliminated, the equation changes.

Even if these weren't point-to-point, smaller vehicles can a) serve more routes that would otherwise be below breakeven for minimum passengers served by a bus, b) be more comfortable for passengers to enter/exit, and c) take up less room on streets. Buses barely fit on streets, they only make sense on very dense thoroughfares as an alternative to rail.

[tomjakubowski]

> c) take up less room on streets.

Not on a per-passenger basis, which is the metric that matters more in streets full of people traveling.

[npunt]

I appreciate that argument and in some/many situations it is likely true, but in others it is not.

What matters isn't people per square foot, it's throughput. And the larger the vehicle, the more likely:

a) people are to want to stop at each stop,

b) multiple people are to get on and off at each stop,

c) the less likely it is to be full, and

d) the more awkward and slow it is in maneuvering on streets.

A/B/D all delay every other passenger, and make 3 mile trips take half an hour through a city.

Cruise Origin isn't the only autonomous bus. The great thing about autonomy is that it allows us more degrees of freedom to optimize transportation needs including offering a variety of shapes and sizes and densities, while removing the labor cost and the physical space cost of a driver.

You can just as easily design an autonomous bus to have density to match a larger bus while retaining the footprint of smaller vehicles, which improves all of the above issues with larger busses.

[jonstewart]

Bus dwell time plays a nonzero role in bus performance, but many multilane urban streets are choked with cars during rush hour. It’s often the case that congestion accounts for the lions share of bus transit time, yet there are typically more people on the bus than in all the cars on a given block. Creating a dedicated bus lane can dramatically improve bus performance, and has a follow-on effect that since congestion has been mitigated, the same set of buses (a fixed capital cost) can, in the same timeframe (fixed operating cost), make more circuit trips. So not only does a single trip get much faster, a bus lane magically produces more capacity.

[kbenson]

The Origin looks van sized, which is perfect. It doesn't take up significantly more space than a car while moving or stationary but can carry more people (and more importantly for congestion, likely will much of the time). Averaging three people per car/van sized vehicle would likely solve the vast majority of current congestion needs, as it would likely halve the vehicles on the road.

[Animats]

The Origin looks van sized, which is perfect.

Remember Supershuttle? They had vans. "Never more than 3 stops". Remember the long, long indirect routes of Supershuttle? Remember what happened to Supershuttle?

[usrusr]

Lack of network effect, perhaps compounded by inadequate routing (I have no idea if they were as good as possible or much worse than necessary).

Network effect must be huge for a system like that. Imagine a large fraction of the cars on the road was shared in the way of supershuttle, you'd already have in that pool a near-perfect itinerary to tie into for almost any trip. And the remainder could easily be fulfilled by assigning a new trip. If you just have a few cars and price for shared occupancy tours will inevitably be much worse. But once you have a critical mass network, route inefficiency will be just a load factor price/performance tradeoff like in a hash-map.

[npunt]

On the other hand, Lyft Line and Uber Pool seem quite efficient.

Supershuttle was concentrated pickup but distributed dropoff, whereas with network effects leading to more vehicles & considerably more efficient routing, you can even that equation out a bit more.

[jonstewart]

Yes, but. It's only perfect if there aren't other cars.

[willyt]

You are right, a bus trip I used to take regularly in London would take 15mins if you got the first bus at 5am, which was quite busy with shift workers. At 9am it would take 45mins with a similar level of crowding. A good portion of the journey was on bus lanes, but there were certain pinch points that killed the journey time in rush hour.

[saberdancer]

Throughput is an incredibly important one, but something that seems to get little attention from the tech world at least as far as I can tell. Is there work being done to improve throughput of normal cars at intersections, or at least semi autonomous ones. I am talking about the accordion effect that happens at each intersection/red light that there is. If a whole column of cars could start moving at the same moment, and then spread out with increase in speed it would result in an improved throughput at critical points in the cities.

Is there work in that area? I feel it shouldn't be a massive technical challenge, cars are stationary, lights are visible and in the future could even "talk" to each other to pass along critical information (if the car infront needs to brake for example).

[npunt]

Agree, those are the longer term efficiencies when we have primarily / only autonomous vehicles on the road. At that point we can optimize from the system POV not just from the vehicle POV. But that's a ways off.

[saberdancer]

But there is no reason why it couldn't be done today, even with non-autonomous vehicles. There are cars on the road that can automatically brake if they discover that you are incapacitated, or that something jumped out infront of you. Having some kind of "assisted red light start" which reduces accordion effect could be an easy way of improving throughput. At first only some cars would have it, and effect would be smaller from a system POV, but with time it would propagate.

[treis]

The metrics that matters most are throughput and travel time.

Theoretically buses are best for throughput, but there's very few routes out there that can fill up a street with full buses. In most cases to totally alleviate traffic we need to take something like 4 people in 4 cars and put them in 1 van. Taking 100 cars and putting them in 1 bus is overkill.

Travel time is where big buses are going to lose. You have to balance density, transfers, and stops. There's no way to get them all. If you want density your buses have to go on the main thoroughfares. Which means you need to transfer to get to the secondary streets. Often trips will look like secondary route -> primary route -> secondary route which vastly increases travel time. Anywhere I want to go by bus in my city takes 3-4 times longer than driving because of this.

The sweet spot is Uber Pool/Lyft Line. You get there much faster and when you account for all subsidies it's price competitive with the bus.

[kylec]

That depends on how full the bus is. A bus remains bus-sized even if there are only a few people on board.

[Nition]

Plus it can come right to your house at (roughly) the time you want it. Closer to being like owning a car.

[jonstewart]

If transportation departments prioritized buses (ie bandwidth) over cars, buses would make a lot more sense on smaller nonresidential collectors and minor arterials. It takes a lot of cars to make up for one bus.

[eropple]

Labor costs are the only thing? Fuel efficiency and traffic (how many double parked Ubers jamming a single lane road will I see tomorrow? Will it be more or less than half a dozen?) would like a word.

[zeveb]

> Labor costs are the only thing? Fuel efficiency and traffic

Is that the case? A quick Googling indicates that buses get 4–6 mpg; let’s go with the pessimistic end of that and assume 4 mpg. Diesel currently costs $3/gal and the average bus travels at 12.7 mph, which means that a bus is spending $9.53/hour on fuel. That’s a lot more than I expected, but how does it compare to bus driver wages?

Another quick Googling indicates that a bus driver makes a little over $15/hour. Double that for fully-loaded costs, and that comes out to $30/hr. That’s treble the cost of the gas, but still in the same ballpark. I’m genuinely surprised that the cost of fuel is so close to the cost of the driver. It may indeed be that fuel efficiency is a factor in bus size.

[eropple]

Yup. Also take into account that many municipalities have buses that run off natural gas, which is both cheaper and not (currently or generally) practical to run in a smaller vehicle.

[npunt]

You're right, not the only thing, but I do think it is by far the primary.

Efficiency-wise a large diesel vis-a-vis traditional car yes the bus wins by a lot, but with smaller multi-person autonomous electric busses I'm not sure if there are any meaningful efficiency gains.

Traffic-wise it may actually be better to have smaller autonomous busses than hulking road giants, because they're not stopping as frequently and they're more nimble. I swear every fifth time I'm around a bus it's stuck idling waiting for a bicyclist or someone to get out of the way, because it's too big to maneuver. Separated bus lanes help, but that isn't a property of the bus as much as urban planning.

[stickfigure]

How many empty or near-empty buses will you see driving around tomorrow?

[snickerbockers]

I guess it depends on where when and where you ride the bus, but every time I get on a bus in San Francisco its overflowing with people to the point that they have difficulty closing the doors.

[baddox]

That's because you want to ride on the popular bus routes, which isn't a coincidence. If lots of people wanted to ride on the empty bus routes, they wouldn't be empty—they'd be the overflowing ones!

[Supermancho]

Bus routes are continually optimized. Empty buses end up losing routes or frequency, as needed.

[topkai22]

That depends on the municipality- I’ve definitely lived places where a goal of the transit system was “access” even if the buses were nearly empty on some routes. I’m not sure it’s an invalid goal eithier.

[zip1234]

How many empty or near empty cars will you see driving around tomorrow?

[pettazz]

> The only reason busses are the size they are is the labor cost

They're big because they fit 50 people inside a single vehicle instead of 50 different cars.

[megous]

Common city busses pack from 120-160 people.

[resonantjacket5]

That's a crush load number usually it's a lot lower. Unless if you're talking about articulated buses

[pettazz]

Just an example number but yeah

[Agustus]

Additionally, buses are certain sizes for political reasons. Constituents want a full sized bus driving through their neighborhood as a sign of respect given, passenger occupancy is not a concern in these situations.