| I see why you'd say that, but the difference between (a) commuter rail lines between the urban core and every suburban edge city [1] vs. (b) high-speed intercity rail between high-population city-pairs ~300 miles apart [2] is one of scale. The commuter rail operates on the scale of the primary city's own metropolitan area, encouraging activity nodes around those stations that are better placed than others. The idealized role of commuter rail is to provide reliability, predictability, and throughput, so that travelers want to concentrate their trips to the same transportation modes and nodes. Meanwhile, intercity rail must balance its need to compete with air travel [3] with its desire to serve larger towns along the line. If it opts to serve fewer intermediate stops, it can deliver a better value proposition for long-distance city-to-city travelers, assuming there's transit or car rental options on the other end, like airports have today. But if it opts to serve more stops along the route, those towns may turn into far-flung exurbs themselves, since they offer quick access to much larger job market. If that happens, you will get sprawl anyway [4]-- the spread of low-rise development on greenfield land as a "cheaper now, don't think about later" response to increased housing demand -- but you'll get the kind of sprawl that's typical of a bedroom community, instead of the kind typical of a mixed-used edge city. This is because the rail will out-range the reach of personal cars from the commuting zone, so the economic integration of the town into the adjacent metropolitan area will be be partial and asymmetric. In California, the decision to route the SF-LA high speed rail through the Central Valley was a sensible one, because the terrain in the Central Valley is more conducive to high speed rail than up the coast through Santa Barbara and San Luis Obispo, and the Valley has significantly larger metropolitan areas than the locales along the coast. Both options require multiple challenging mountain range crossings. It's the SF-LA link itself that's tenuous to justify, because there's perfectly fine airports available today to anyone who wants to hop between the two. [1] https://en.wikipedia.org/wiki/Edge_city [2] The approximate distance of Chicago-Detroit, Chicago-St Louis, Chicago-Cincinnati. [3] Air travel is the most direct competitor of intercity rail, because both will discharge you at your destination with no car, and compared to a commuter scenario, the intended destinations of passengers will vary greatly within the broader geographical area. [4] Sprawl spreads because cheap greenfield land exists at the momentary edge of all but the most geographically-constrained areas, many developers prefer these these cheap-to-build sites, and many people do prefer low-rise single-family homes with yards. Sprawl will always spread if housing demand outpaces supply unless you forbid it by law or ordinance, because new construction on greenfield land confers tangible benefits to those who can afford it. |
availability of land is a lesser factor for sprawl compared to reach. practically no one lives in suburban lands (like intraurban mountainscapes) unserviced by roads. sprawl is directly correlated to where we put roads, and less so to where there is open land. further, roads (and other infrastructure) are heavily subsidized, both directly and due to uninternalized externalities.
internalize all those externalities and we'd have much less debate on this topic. folks could simply choose what they prefer relative to actual costs.