What If? 160 - "Transatlantic Car Rental"

[LingEarth]

https://what-if.xkcd.com/160/

I'm gonna use this trick to go visit our European forumites.

Just a week until what if 2 comes out!

[somitomi]

she jokingly suggested that given a sufficient quantity of rental vehicles, she could eventually get to Europe by driving east repeatedly. The question is, how many vehicles would it take to build a vehicle-bridge across the Atlantic?

Let's see what number we get if we apply this method (drive east until it stops working) to other vehicles:
- ships: 1 (might be 2 if you encounter severe weather)
- airplanes: 1 (might be 2 if you encounter severe weather)
- trains: the volume of the average boxcar is somewhere around 20-30 times that of a road-going car, so assuming a stack of railway cars and locomotives has similar dynamics to a car-heap [I'm not aware of any actual such heap, although I've seen photos of scrapped LA streetcars stacked 3 levels high], you'd need at least a couple hundred million just for the continental shelf. In reality a significant number of those cars isn't a boxcar, but some variation of a gondola or a flatcar, the actual number is probably higher. Unfortunately, there are only about 1.6 million railroad cars in the US [1]. You should probably take a shortcut through the Channel Tunnel.
Another small hurdle in this plan is the fact that trains need tracks to go anywhere beyond a few meters.
- submarines: 1