Harvard economist Edward L. Glaeser is working on a series of posts analysing the costs and benefits of high speed rail.
So far his results have not been encouraging for rail advocates, though his results are riddled with loose assumptions and figures that are easily challenged.
Today he tackles the environmental benefits of high speed rail.
The environmental and [reduced traffic death] benefits of rail are real, but the magnitude of the social benefits from switching modes seems is quite small relative to the cost of the system.
His cost calculations are pretty loose, though, and Ryan Avent at the StreetsBlog, thinks his conclusion is meaningless:
Today, Glaeser seeks to estimate the environmental and congestion benefits of high-speed rail, and he quickly stumbles into error once again. Once more, he fails to take into account population growth, despite that variable’s crucial importance to this analysis.
Instead, he assumes that rail will merely poach riders from the ranks of current drivers and fliers. Not only does this miss that in the coming decades millions of additional travellers will move to the area, but it also ignores the effect of population growth on congestion costs at highways and airports.
Houston and Dallas are among the most congested of the country’s largest cities, and growth in annual delays per traveller in Houston and Dallas has dwarfed increases in delays in peer cities over the past decade, rising by about 50 per cent between 1997 and 2007 compared to increases of around a third or less for the country’s other large metropolitan areas.
Rapid population growth is overwhelming existing infrastructure between the two cities. Even if the rate of population growth slows, significant new capacity will have to be constructed to prevent major increases in congestion costs.
In that case, one must either update the environmental analysis to include significantly higher congestion costs for roads and airports, or one must set the emission costs of new road and airport construction and set the numbers for new capacity against the emission costs of rail. Or one can simply do as Glaeser does, and ignore the whole issue.
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