Let's not speculate on how evacuation can be handled in a regulation-compliant way. I can certainly imagine a system where trafic is reliably halted when pedestrians are detected on the main lane. You might counter that such a system is unreliable, and until a regulator looks over such a proposal, it's impossible to predict their decision. Let's just agree that there is no fundamental physical reason that prevents humans traveling in vehicles down 3m wide shafts - see for example elevators.
I don't really understand what you mean by maintenance of the system used for diverting from the main lane - it's essentially the same thing as an exit ramp from a highway, but much shorter since the reliability of the automated driver is a built-in design factor.
The lane shift maneuver requires about 1s, so about 15m of widened tunnel at the entrance and exit of the stations. An additional 20m of is required for reliable deceleration and acceleration respectively, which would be handled by dedicated tunnels serving the station. I agree that these interfaces would handle much less vehicles, but it would drive down the throughput of the respective station, not that of the main lane.
Regarding the size of the underground station - why not make it on the surface? You can have much steeper ramps in an automated, controlled system, if for example de-icing is guaranteed near the surface with dedicated heaters, the quality and grip of the tires is controlled etc. Essentially, any down-town parking can be transformed in a very large station by dedicating o few hundred m^2 for these ramps.
> Let's not speculate on how evacuation can be handled in a regulation-compliant way.
If we're going to make a valid comparison between different systems then we have to compare them under the same regulatory regime. A lot of the costs of real-world subway systems are down to regulatory requirements, so comparing an imaginary system that's exempt from those regulatory requirements is going to be very biased.
> I don't really understand what you mean by maintenance of the system used for diverting from the main lane - it's essentially the same thing as an exit ramp from a highway, but much shorter since the reliability of the automated driver is a built-in design factor.
Highways try to avoid having exit ramps in tunnels, because fundamentally you're creating the possibility of a vehicle crashing into the pointy bit (or at best a blank wall). If you're relying purely on automated steering to avoid that, inevitably sooner or later a pod is going to hit it, if only through mechanical failure of the steering system.
> Regarding the size of the underground station - why not make it on the surface? You can have much steeper ramps in an automated, controlled system, if for example de-icing is guaranteed near the surface with dedicated heaters, the quality and grip of the tires is controlled etc. Essentially, any down-town parking can be transformed in a very large station by dedicating o few hundred m^2 for these ramps.
That doesn't solve the problem - the reason tunnelling is expensive in these areas is because land is expensive there. Parking has an absurdly small capacity compared to transit. Even bus stations just can't unload enough people quickly enough in the space available in truly dense city centres, and this pod system is going to need a lot more space per person than a bus station.
I don't really understand what you mean by maintenance of the system used for diverting from the main lane - it's essentially the same thing as an exit ramp from a highway, but much shorter since the reliability of the automated driver is a built-in design factor.
The lane shift maneuver requires about 1s, so about 15m of widened tunnel at the entrance and exit of the stations. An additional 20m of is required for reliable deceleration and acceleration respectively, which would be handled by dedicated tunnels serving the station. I agree that these interfaces would handle much less vehicles, but it would drive down the throughput of the respective station, not that of the main lane.
Regarding the size of the underground station - why not make it on the surface? You can have much steeper ramps in an automated, controlled system, if for example de-icing is guaranteed near the surface with dedicated heaters, the quality and grip of the tires is controlled etc. Essentially, any down-town parking can be transformed in a very large station by dedicating o few hundred m^2 for these ramps.