I always see that image referenced and it's kind of BS. it assumes the buses are filled to the brim constantly but the cars only ever have 1 person it. It also doesn't take into account the transport to and from your door on both ends. It also doesn't consider the inefficiency in wait time.

The ideal transport would be a cocoon just big enough for you to fit in that picks you up at your door and gets you to your exact destination with minimal energy overhead. I'd argue a self driving car is much closer to that ideal and we can iterate our way much easier to it than public transit.

"It also doesn't take into account the transport to and from your door on both ends."

This type of design is terrible for average health outcomes [1]. We should not be optimizing for this. Walking to the bus stop is a good outcome. We should optimize for better more frequent bus routes, but "door-to-door" is unnecessary and counter-effectual.

The rest (iteration speed, filling a bus to the brim etc.) are just political problems just as intangible as "lets build better roads (public infrastructure) for autonomous cars", so we can put that aside.

[1]: https://www.bu.edu/sph/news/articles/2023/us-neighborhood-wa...

we don't have to couple exercise with transport. We don't say planes are bad because it reduces the number of cross country hiking trips people take.

On filling a bus, I think its a fundamental shortcoming of having fixed routes that they'll never be as efficient as point to point transport, especially electrified transport. i'm not really making a political argument.

I agree with the second point but given as 80% of city transports post-covid is back to being fixed commutes along fixed routes, I'm happy optimizing that along transit ways. I don't really care what happens with the remaining 20%.

Right now, nearly 100% of travel is with "personal cocoons", totally unnecessary (other than for political reasons) and creating immense downward pressure on health and social outcomes. In terms of levers the government has on health and social outcomes, transitway design is a big one, and it should use it.

The fact that its done badly in America is a political problem, and if you have any political power it should be expended fixing that, not rolling back public transit.

I think if these cocoons costed $2.50 a trip you might think differently. I think driverless cars + some iteration on the vehicles themselves gets us there (without subsidies!).

People love the equity argument for public transit. Non personally owned, ubiquitous, driverless, cheap, efficient and most importantly convenient cocoons would increase equity a whole hell of a lot more than the traditional definition of public transit imo

For the 80% during peak rush hour? Just based on spatial efficiency that pricing doesn't seem attainable.

Maybe if you were to throw infinitely scalable roads in the way of Boring Tunnels, but now we are off in la-la wish land.

Just seems like a lot of work for what is a solved problem (atleast in the Pareto sense).

What is this solution we already have that you speak of? It takes 40 mins to go 3 miles in SF using public transit, between two popular destination pairs.

Fleets of driverless cars lets you do traffic shaping in time and space. Plus the marginal energy cost is basically nothing. It's basically all fixed cost BUT it's not like a transit project in the sense that you don't have to allocate a bunch of capital ahead of time and wait 10 years and then maybe get what you wanted (or not). Driverless cars are helpful the moment the first $200K car hits the road.

It takes 40 mins to go 3 miles using a car too at most peak times. It’s obviously not fair to compare a perfect autonomous transportation method with the current imperfect state of public transit.

As the population grows the driving times will get worse much faster than in transit because again, spatially, it just doesn’t scale well.

If you take 20-30% of everyone on a BART train and put em in autonomous cars with human drivers in the mix (like in the marginal $200K case tomorrow), what you have is abject chaos on the streets.

Every negative you mention about public transit is a political problem (other first world countries can deliver public transit project in a matter of a 1-2 years and at a fraction of the cost).

no. i literally compared a common route on google maps for bus vs car, no transfers on the bus. car was 20 mins, bus was 40 mins when you factor in walking to the stop and waiting and walknig to your destination. to be fair, didn't consider time to get parking but its still less than 20 mins.

population growth - you know this isn't a thing right? we have very slow population growth and we can scale our way out of it with existing infra. more driverless cars = less parking = two more lanes on most streets. that can double throughput.

yes public transit is a huge political problem - so whats your solution? because the tech for public transit has existed forever so why isnt it better in the US? You cant just blame politics and then do nothing. You also cant say "we just need to advocate!" because, well, if it were that easy it would have already happened. Driverless cars are a good solution precisely because it uses existing infra and I think the political hurdle can be much much lower.

"population growth - you know this isn't a thing right? "

well then you can definitely put away your dreams of a magical $2.50 pod travel. You need people, more people, young people to build all that. And if we're saying flat and low population growth that dream is over, all conversation can stop.

But if we can turn things around on population, public transit is the only way things scale. Personal travel pods/cars are a current stopgap that only kind of works for our current population levels. Please re-measure car travel times at 5:30pm on a Wednesday evening when 80% of all trips happen, like I've mentioned, the remaining 20% are highly inconsequential to overall transportation design.

we already have working driverless pods.

you seem to think there are only 2 worlds: 1) population is exploding and everything has to scale 10x or 2) population isn't growing and apocalypse.

There is a 3rd outcome: slow, moderate growth at 2%/year and things need to scale just a little.

the bus doesn't have to be full to be a more efficient use of space than cars though. A typical (non-articulated) bus is the length two-three cars at most.

It is worth noting that personal vehicles are getting larger, so the amount of ridership required for a bus system to be more efficient than cars is only going down for the foreseeable future, even before getting into second order effects.

yeah but it does have to have enough people for it to be efficient moving around that giant wall of metal

turns out that compared to lugging a living room around for every (average car occupancy of) 1.5 people on the road, a bus system has an extremely low efficiency bar to cross.

buses are roughly equivalent in energy per passenger mile vs cars when you consider average loads for each.

Worse, everyone in a car us tailgating. If you maintain a proper safe following distance cars do a lot worse.

The ideal transport is be a bicycle, or an e-bike for cities with hills. The problem is that bike lanes are still not great. I bike commuted in SF for years. Bikes are ideal "last mile" transport too, for long commutes trains with bike carriages can be added in. Numerous cities in Europe show this works very well. Having said that, it's an ideal which I fear is probably far from reachable for most people given the way cities have been built, and infrastructure priorities in the US do not favour bikes.

I love biking and am excited by the possibility of the roads having more attentive and courteous Waymo cars and fewer speeding and drunk human drivers. (A man on bike was killed by a drunk speeding driver 24 hours ago 300 feet from my home.)