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There is a functional limit for induced demand! But it effectively can't be reached in urban and suburban areas because cars scale really poorly. Cars don't sca
by ComradeTaco 9y ago
There is a functional limit for induced demand! But it effectively can't be reached in urban and suburban areas because cars scale really poorly. Cars don't scale well for three main reasons:
(1) Cost. Building roads and highways inflicts both huge upfront capital costs and maintenance costs. A typical highway line has a throughput of 2,000 cars per hour.
(2) Real Estate. Building the level of roads necessary to meet induced demand+ would take up an extremely large amount of land that can only be used for vehicles.
(3) Local Roads. Local roads can only absorb so much capacity and they have functional throughput limits. If you wanted to make them faster, homeowners couldn't have driveways.
If you really wanted to, you could possibly make a city where driving is king and there is effectively no congestion. It would just be absurdly expensive and hostile to everyone who doesn't have access to car.
- pas 9y agoOnly cost is important for tunnels, because there's still space sufficient for hundreds of layers of tunnels below cities.
- jcranmer 9y agoOnly if you build tunnels that no one can get to. Road tunnels still need to obey grade and (horizontal and vertical) curvature restrictions. For example, every story down you push a tunnel, every city block longer an access ramp needs to be. And the deeper you make tunnels, the more difficult ventilation and pumping becomes.
- zootam 9y agotheoretically one could avoid vertical curvature issues by connecting the tunnels with large shafts, similar to elevators in skyscrapers.
- chiefofgxbxl 9y agoThis may slow down traffic, based on the vertical speed of the elevators and how quickly people in cars can board the elevator. I'm not sure which one would be quicker: having a really long access ramp (long because of the tunnel's depth), or having to wait in line to board an elevator that moves quite slowly.
- aedron 9y agoMusk's system uses elevators.
- thatfrenchguy 9y agoLook at Paris, this is not true.
- thatfrenchguy 9y agoLook at Paris, this is not true.
- vidarh 9y agoNow figure out how to get people up and down, and how to cool them. Places like London has problems with both already.
- qu1j0t3 9y ago> you could possibly make a city where driving is king and there is effectively no congestion. It would just be absurdly expensive and hostile to everyone who doesn't have access to car. This is exactly what has been done in most of North America, except for the "no congestion" part.