Trains, Tesla and People Moving for Workday Commutes

[bhtooefr]

From General Discussion:

Having spent a bit of time in the US including staying at relative's homes - I think I can be confident in saying that the root cause is that you live in extremely low density housing areas commuting into enormous cities with many centres. The chances of being able to walk to public transport that takes you direct to your place of work (without waiting for changes of transport) is close to 0%. Walking to a Walmart from the store next to it involves walking a mile by a 4 lane freeway without a sidewalk. I take public transport (train into London and then the subway) regularly. I doubt I would in the US much and it has nothing to do with the stigma or quality. Robotaxis will potentially increase public transport across the world as it makes the changeover a great experience. No cost of parking or finding a space.

Worth noting that the extreme low density housing areas were enabled by cars, but they were created by a combination of 1940s nuclear defense policy, and a couple hundred years of racial tensions (white people so terrified of black people that they fled cities for extreme low density suburbs and exurbs, hoping that the poorer socioeconomic status of black people would keep them from getting cars). Plenty of other countries tried suburbs, but the cities didn't collapse, and the suburbs were close in enough to have mass transit densities.

Note that these tensions still exist, causing people to believe that cities are lawless areas where you'll get killed, and opposing any forms of mass transit development. There is some movement back into cities, but it's typically younger professionals, and into heavily gentrified neighborhoods, without all of the services necessary to support full life in cities, only single people.

 

[NicoV]

So I'm going to distinguish between those two points: higher frequency vs. higher geographic coverage. I'm not sure what the political situation is in Belgium. But basically, if there's advocacy for higher frequency on the mainlines through the high-rise areas, it is correct. If there's advocacy for more stations in the Ardennes, it is incorrect.

The political situation is that some parties consider mobility a fundamental right. If you don’t have the means (in practice: a car) to go where you want to be, you should have a reasonable way to get there via public transport.
So that means more geographic coverage, more trains later and earlier on the day (after 23h you can forget about getting home with public transport). Those are exactly the situations where the trains will run mostly empty, so that will drag down the average efficiency. We have bus schedules that are so lowly occupied that they stopped scheduling them, you now have to call upfront that you want to take that bus, and then a small bus will do that route on that time of the day, almost like a taxi.

Which gets me back to robotaxis: they would be excellent for those situations.

 

[Cartegena]

Getting the right vehicle fit to meet specific demand is important. I think the tendency in public transit has been to error on the side of larger occupancy capacity than needed. This may be economically motivated by rationing the cost of the driver. Public transit folk ridiculed Musk for suggesting an autonomous transit vehicle for small occupancy. But if occupancy is less than 25% of capacity, something is really wrong with the size of the vehicle. To wit, you could put out vehicles at half the size saving a load in fuel and wear on the road, and still struggle to get occupancy up to 50%. Once we are talking about autonomous vehicles, the economics of rationing driver cost goes away. So I think autonomous will be a watershed moment for public transit. I think smaller vehicles will become much more economical.

Some relegated to public transportation prefer more personal space. Ever been in the Mexico City metro during rush hour? They enforce separate cars based on gender.

 

[SwTslaGrl]

People mover (pod style?) anno 1907

 

[Sancho]

Comparing trains to robotaxis is apples to oranges. Trains in most cases consume far more time and personal energy due to some combination of:

1) having to get from point A to the train station
2) waiting for the train
3) having to switch trains, including having to walk between platforms and waiting for next train.
4). Stopping for intermediate stations
5) having to get from station to point B.

Depending on the extent of these 5 factors, a person would pay up to 20 times more for a robotaxi. And that’s before the premium you’d pay to not stand in a crowded subway car during the ride.

So sure, mass transit is more efficient, but it’s not a comparable service.

But it all comes back to the feasibility of building enough tunnels (and enough elevator entry points to them) to eliminate traffic congestion. In traffic clogged Manhattan, robotaxis will be no better than the current taxis, and I will continue to opt for the subway.

 

[ggr]

People mover (pod style?) anno 1907

View attachment 364924

Good thing it presumably can't do a 10 second 0-60.

 

[jhm]

*Sigh* It's not. It's slightly on the low side, but not much. (Now, 10% of capacity, that would be bad.)

This is a complex topic, but the things you need to know to start with...

-- Average occupancy of private cars is 1.59 people per vehicle, and the vehicles typically have capacity of 4 or 5 (sometimes 7). If we assume a vehicle capacity of 4.5 (probably an underestimate), that's 35% occupancy. This is overstated because sometimes the driver really is just ferrying other people around (taking kids to school etc.)
-- Fixed-route transportation has a peak segment. If have near-zero occupancy at the ends of the route, and a full bus / train in the middle of the route, you have average occupancy... of 50%. This is fairly normal, and about as good as it gets. There's always an effort to design routes with "anchors" on the ends to bring the occupancy up, but you'll always have a peak segment.
-- The marginal costs of running larger vehicles are minimal. Yes, part of this is leveraging the cost of the driver, but also of the wheels, the drivetrain, the crumple zones, the fixed energy costs of operation (eg heating), etc. Think about it -- how much more does a stretch limo cost to operate vs. a regular limo? Not much.
-- The marginal costs of running smaller vehicles are severe. When you fill up your bus or train, you have to dispatch extra vehicles on short notice, which is sometimes impossible -- or turn away customers, which creates ill will and leaves customers with few alternatives (remembering that this happens at *peak travel* when cars are hopelessly stuck in congestion). Mass transportation fleets are sized for the peak, and they have to be.


You are, to put it bluntly, wrong.

At most, it might make sense to run shorter trains more frequently (Vancouver SkyTrain) rather than longer trains less frequently (subway systems with drivers).

So if cars are running at 35% capacity while buses are doing well to run at 25%, then we have a persistent situation where cars have substantially better passenger mile fuel energy efficiency than buses. This undermine the environmental case for buses. Granted higher occupancy vehicles may be a better solution for urban congestion, but that is a separate problem.

Please do not lecture me about geographical constraints in high density areas. If trains and buses are well utilized in such areas, I have no complaint with that. My point was simply that autonomous vehicles shifts the economics and dispatchability of smaller vehicles. I have made no such claim that this would displace trains or buses that are well utilized. Improving the economics of smaller vehicles simply put more tools in the mass transit toolbox. I think we really do need better tools at the lower density end of the spectrum of transport need. At that end of the spectrum, road space is not really an issue, certainly not the issue it is at the higher density end of the spectrum.

 

[jhm]

Some relegated to public transportation prefer more personal space. Ever been in the Mexico City metro during rush hour? They enforce separate cars based on gender.

I think this is one of the motivations for private cars. I confess that I don't really like riding in a train or bus when it is so full that many people must stand and hold straps. This gets especially uncomfortable when certain passengers are suffering from colds, the flu or worse.

 

[Cartegena]

I think this is one of the motivations for private cars. I confess that I don't really like riding in a train or bus when it is so full that many people must stand and hold straps. This gets especially uncomfortable when certain passengers are suffering from colds, the flu or worse.

Here's a cynic's take:

 

[landis]

Here's a cynic's take:

Can't believe I wasted my time watching that.
Speaking of snake oil salesman. Sort of missed the entire point that smaller diameter is why it can be cheaper and that actual 10x cost advantage only comes with the v3 boring machine.

Cynic is too generous of a characterization.

 

[mongo]

Can't believe I wasted my time watching that.
Speaking of snake oil salesman. Sort of missed the entire point that smaller diameter is why it can be cheaper and that actual 10x cost advantage only comes with the v3 boring machine.

Cynic is too generous of a characterization.

They have 10x now. LA test tunnel was 10 million per mile, that is 1/10 of light rail on the surface let alone subway. (yes, yes, one boring tunnel vs a dual track subway with all the fixings. Still is doing well cost wise.)

The 15x speed will be with 3rd gen, which should drop cost even further.