COMMENT OF THE DAY: WHAT IT WOULD TAKE TO BUILD A SUBWAY IN HOUSTON “A subway WILL work in Houston, albeit at a significantly higher cost. I’m a civil engineer who builds tunnels, nationwide. They’re not even significantly more expensive in Houston than elsewhere. Tunnels in LA, NY, Chicago, Montreal, London etc all have to deal with bedrock — which is very expensive to tunnel through. Instead, Houston uses open-cut excavation and massive soil amendments + ground water pumping to tunnel. For example — the depressed portions of US-59 from Shepherd to Montrose (or the depressed portion of Beltway 8 from Boheme to I-10) are essentially a tunnel with no roof because they’re lower than the bayou and the ground water table; it took expensive soil amendments and pumps to build that, the same as a subway. Our commuter rail tunnel projects in LA are bidding for between $18M-$20M per mile of track, while the at-grade portions are only about $4M per mile. We consistently find that tunnels cost about 4x-5x as much as at-grade track. Meanwhile, elevated track costs roughly $25M a mile (6x at-grade costs). . . .” [Ornlu, commenting on Comment of the Day: How About a Rail Line Along the Bayou?] Illustration: Lulu