BRT vs Metro

By Neil Padukone

When Bogota, the cradle of the world’s Bus-Rapid Transit (BRT) thinking, explored a metro system, debates over preferability raged.

Transit demand depends not only on population and demography, but also on spatial distribution. If people live far away from a metro station, that “last mile” might make traveling so difficult and time-costly that taking the metro is not worth it at all.

Of course, an argument for a metro is that, over the long-term, big infrastructure like metros would induce demand for high-density (potentially mixed-use) living and business investment. In the 1920s, New York’s subway system extended to a barren and unsettled Queens, NY (see Figure 1). That changed tremendously when Manhattan boomed and its residents needed new housing; the area has become one of the highest density areas in the country (see Figure 2).

Fig 1. Queens in 1920s

Fig 1. Queens in 1920s

But the potential for induced demand depends on migration & growth patterns: it won’t happen if there isn’t enough growth to underwrite it. The “People Mover” in Detroit was supposed to induce demand in a contracting Detroit economy. But that wasn’t sufficient; it wound up being a glossy project that wasted money — designed for 15m people, it only served about 2m, and the cost per passenger mile was $4, compared with the New York subway’s $0.30 per passenger-mile.

Fig 2 Queens Today

Fig 2 Queens Today

The thinking in Detroit — and elsewhere — evokes another perennial consideration for the development of metro systems: aesthetics. Metros give off an appearance of legitimacy, sexiness, investment, and stability that buses may not. This sexy infrastructure may well attract other investment, but it often comes at the huge expense of massive state subsidies and deficits: Metros are almost never financially solvent. The only two subway systems in the world whose operating costs are covered by the system are in Hong Kong, which covers operating costs through real estate, and Singapore, which has long had an aggressive car-restriction policy that drove the metro’s farebox ratio up to 126% of operating costs. (Capital costs everywhere require subsidies).

For a long time, metro systems were the only technologies capable of providing the sort of scale for longer-distance urban mobility. But with the improvement of bus technology — segregated lanes, GPS-based sensoring, and tinier capital costs — BRT generates comparable (though admittedly unequal) scale with the long-term ancillary benefit of lowering traffic congestion by taking up space and dis-incentivizing car usage.

The respective capital (costs) of metros and BRTs are another consideration. During its construction and development, the problems that afflict any burgeoning BRT would also afflict the Metro: the time for implementation would bring little short-term respite, and in fact cause greater delays in the interim. And in the long-term, BRT corridors are far more flexible and mutable: If demand for a corridor increases or diminishes, it can simply be deconstructed and redirected for an extremely low cost — relative to subway systems, which are fixed and can’t be redirected quite as easily.