&gt; Even Tokyo has most of it&#x27;s trains above ground. See Yamanote line with 29 stations versus the 16 cumulative underground stations that both the Tokyo Waterfront Area Rapid Transit and Saitama Rapid Railway Line serve.<p>I&#x27;ve lived in Tokyo for a year, and this comment is grossly ignorant.<p>First of all, Tokyo Metro is just <i>one</i> subway <i>company</i> in the region. Tokyo Metro according to Wikipedia has 142 unique stations, most of which are underground.<p>For surface trains, the Yamanote loop line circles central Tokyo, with Chuo-Sobu cutting through the center. There are other surface trains that <i>feed</i> into central Tokyo but don&#x27;t necessarily take you <i>through</i> Tokyo. There are some trains that also run along sections of the Yamanote line like the Keihin-Tohoku line and Saikyo line.<p>Other than those lines, if you want to travel around central Tokyo (within the area circled by Yamanote, you will most likely ride a Tokyo Metro subway (underground) or a Toei Subway (underground). Toei is the other major subway company in the region.<p>If anything, Japan and Tokyo is proof that SF and LA have no reason to <i>not</i> build subways despite their seismically active areas. Remember, Japan, including the Tokyo region, was hit with a 9.0 magnitude earthquake recently and many other high magnitude earthquakes in the last century alone. Tokyo is proof that earthquakes can be mitigated.<p>If there&#x27;s one engineering failure of Tokyo it would be reclaimed land. A large portion of Tokyo (famously Odaiba, and Haneda Airport) are built on reclaimed land. This type of land shows problems especially due to earthquakes. For this reason residents tend to shy away from purchasing houses in these areas because there&#x27;s a high risk of issues with the soil and foundations. But this makes perfect sense, reclaimed land is basically dumping dirt into what used to be water to make more land.<p>---<p>The only way this comment gets remotely close to accurate is if it is counting for the entire Tokyo <i>region</i> and not just Central Tokyo. But this would be the equivalent of comparing the entire Bay area. Outside of central Tokyo, the trains do run on the surface. But Tokyo uses trains as a primary means of transportation so lines can continue for hours as they go into remote areas of Tokyo or connect to other lines despite different ownership of the track. For example it is possible to take a single train (no transfers) from Haneda airport to Narita airport. The ride will take over 2 hours but you will have technically traveled on 3 separate lines operated by 3 separate rail companies. Oh and one of those lines is a subway line.