That's assuming you only have 1 train. Trains leave between Osaka and Tokyo every few minutes at rush hours, and travel at speeds upto 300 km/h. They are timed to nearly 1 second accuracy, monitored precisely by computers, and each station has multiple tracks to buffer the traffic.

Tokyo's station serves 3000 trains daily and some 415K passengers per day as of 2013.

The Chinese high-speed rail system also deals with similar levels of passenger traffic. Shanghai's Hongqiao station for instance has no less than 30 tracks, can hold 10K passengers at the same time, and comfortably serves an average of 210K passengers per day (much more on holidays), and it is only one of a few railway stations serving the area.

Trains scale well if you do them right. Technology has come a long way.

The assumption was that you have 800 train cars and that you would load roughly 33 cars every 10 minutes.

But let's take your numbers: 415K passengers per day. Let's keep the same three day evacuation period. That's ~1.2 million people. Leaving 5 million in Houston.

Here's the point: Evacuating millions of people over a weekend is a gargantuan task. Magic words like "train", "plane", or "automobile" don't instantly solve the problem.

Tokyo and Shanghai has MUCH more people compared to Houston and it makes more economical sense to have more train infrastructure

Tokyo's population is about 4 times that of Houston. So fine, instead of running 3000 trains a day from the central station, you can run at least 750?

That's what life would look like if people in the US actually used trains on a regular basis.

In any case, all I'm saying is that if a massive number of people need to be moved, trains can scale well, additional reserve capacity can be deployed during evacuations, and it's also a lot safer than having hundreds of thousands of people taking to the roads in bad weather.

Googling Houston metropolitan population gives 6.5 million. For Tokyo you get over 37 million. So Tokyo is 5.7 times Houston. Having been both places, Houston is much smaller. Houston also can't build subways, they'd always be flooding.

If you include the entire metropolitan area, then there are many, many more train stations to factor in than just the central stations. But in any case, order-of-magnitude wise you get the idea. Houston isn't that small and many cities around the world with even 1 million people have excellent public transportation.

One word: cars. No other explanation needed. Car culture and car manufacturers' interests play a big part in the current inadequacy (by western standards) of the US infrastructure.

Two words: population density

Tokyo is crammed and that's why trains work great over there. They wouldn't work in US city with suburban sprawl.

suburban sprawl is arguably a result of the obsession with cars

The city I live in is in suburban sprawl mode right now. The main reason is apartments in city cost a fortune if you want reasonable amount of space. For family or hobbies or whatever. 1 bedroom apartment close to city centre == 2 bedroom apartment within city limits == 3-4 bedroom house with proper backyard and garage and everything just outside city limits.

this. A lot of Berlin's public transport infrastructure (a city that definitively sprawls in the suburb, compared to other EU capitals) was built in the late 1800/early 1900. Check density stats for Berlin.

If "population density" was really the dominant reason, then New Jersey would have a public transportation system far better than most countries in Europe.

SHINKANSEN!