Like, I said, there are two things: 1. The theoretical throughput limits of cars on highways vs trains, for transporting people, is drastically in the favor of

Like, I said, there are two things: 1. The theoretical throughput limits of cars on highways vs trains, for transporting people, is drastically in the favor of trains. Generally 1 car per 2 secs per lane - 1.5 people per car on average = 3 people per sec on a 4 lane highway. On the other hand a 15mpg train, moves 6m per sec, with a width of 2 meters = 12 m^2 per sec = 12 people comfortably per sec. While this is a relatively slow train, and we are comparing a train (land mass = 1 highway lane) with a 4 lane highway, the math is still drastically in favor of trains. this still holds, even if autonomous cars can achieve a 100% increase to highway throughput limits. 2. Seattle may not need the level of throughput only achievable by trains. You're probably right that currently Seattle does not and will not need more throughput than cars on highways can achieve. However, I don't think this holds true as time continues indefinitely into the future.