BRT has become commonplace now in the U.S., with cities large and small either planning or having already implemented BRT.

The mode is also being used for a wide variety of applications, as trunk routes, feeders and circulators. In fact, the biggest implementation challenge, which I’ll discuss in a moment, is that there is no single definition of BRT.

The fastest growing mode in history?
In many ways, BRT is not a new concept. We have had dedicated lanes in city downtowns and busways for years in the U.S. and even longer in other countries. The first systems to be called BRT occurred in the early 1970s in Curitiba, Brazil; the first policies were started in the U.S. in the late 1990s.

Since then, more than 3,300 miles of BRT have been launched in more than 200 cities throughout the world, according to EMBARQ, an international group that has tracked this. And that number is an undercount, because it only counts those systems with a majority of its network in dedicated lanes or separated busways. The most common type of BRT in the U.S., of course, has less than a majority of the route length in dedicated lanes, but has all of the other elements that define BRT.

Why BRT is difficult to understand
Other elements that define BRT, such as such as branded, visible stations and shelters and branded buses with higher-tech amenities, have also been around for a while. Perhaps the newest twist is giving buses traffic signal priority or advanced propulsion, such as all-battery power. What really defines BRT is how these elements are used together, but even that is a large number because these elements are applied according to what the situation dictates, making it a very flexible mode. Which is why BRT might confuse the general public, and why clear, consistent communication is so essential to implementing a successful BRT service.

Federal transportation policy since 2012 places BRT in two basic groups: “fixed-guideway BRT” and “corridor-based BRT.” Yet the only real difference is that fixed-guideway BRT has a majority of the project in dedicated lane, while the other doesn’t; all of the other elements, such as branded stations and buses and faster, longer and more frequent service, are the same.

Because each city defines what it means by its version of BRT, having all of the advocates on the same page, especially through a development process that takes years, is often the difference between success and failure when it comes to any public transportation project, but especially with BRT.