Policy Update

Busway vs. Rail Capacity

Separating Myth from Fact


One of the major misconceptions in U.S. transportation planning is the claim that rail has inherently higher capacity and provides better service than buses. Rail supporters aim to exclude bus modes from the list of alternatives as early as possible in any feasibility analysis. That is because buses almost always look good once they are properly analyzed for several primary reasons:

  • The right of way-typically a lane of asphalt-is invariably cheaper than an assemblage of rails and power supplies and signals;
  • Buses themselves are mass-produced by highly competitive manufacturers whereas rail cars are custom-designed by a handful of companies worldwide; and
  • Like other motor vehicles, buses are adaptable and can take people from close to the actual beginning of their trip to close to the end of their trip. Moreover, as traffic and demographic patterns change, so too can bus routes. Rail, by contrast, is much more static and is substantially more limited in its ability to offer “door to door” service.

In an era of downsizing and economic decentralization away from core urban hubs, the small scale of the bus and its adaptability are a huge advantage over rail.

Veteran transportation analyst John F. Kain of Harvard summed it up: “With few exceptions studies of the cost-effectiveness of alternative modes have found that some form of express bus system, operating on either an exclusive right of way or a shared facility, would have lower costs and higher performance than either light or heavy rail systems in nearly all, if not all U.S. cities. The tendency of policymakers to ignore the abundant evidence on the superiority of high-performance bus systems is explained by a prior commitment to rail and a willingness to ‘cook the numbers’ until they yield the desired result.” Other scholars and researchers have come to the same conclusion: rubber-tired transit on roadway lanes is, in nearly all cases, more cost-effective, more flexible, and enables a higher level of service to riders than rail.