A Bus Rapid Transit – BRT – system is coming to Washington, DC in the spring of 2014. The proposed corridor will connect Crystal City in Arlington with the Potomac Yard in Alexandria.
 
This is good news for DC residents, who are currently dealing with the worst traffic in the country. DC commuters lose an average of 67 hours per year because of congestion, resulting in an additional 32 gallons per year per commuter of gasoline wasted.
 
BRT systems address traffic problems by creating dedicated lanes for buses. As shown in the above photo of Delhi, cars are physically restricted from bus lanes. This allows buses to travel faster than cars, making them a more attractive transport option for commuters and reducing car usage. Basically, a BRT is an aboveground subway, except that it costs 1/10th the price. Washington, DC is following in the footsteps of many developing world cities that have already put in BRT systems. Curitiba, Brazil, was the first to implement a BRT system in the 1970s. Many other cities have also put in similar systems: Bogota, Colombia; Buenos Aires, Argentina; Guangzhou, China; Delhi, India; Jakarta, Indonesia; Dar es Salaam, Tanzania; and many more. These cities have benefited from BRTs in many ways. In Bogota, the Transmilenio BRT system has reduced greenhouse gas emissions by 330,000 tons per year. BRT systems also improve air quality, increase mobility for the urban poor, and decrease road deaths.
 
Listing only these direct benefits misses the broader impact that reformed transportation systems can have on a city. David Roberts has an excellent piece on "widgets vs. systems" for background on this idea. In short, if you change the "widgets" of our transportation systems – by, for example, improving the fuel efficiency of cars – there will be a real, but modest benefit. But if you modify the system itself, the changes can be transformational. If a city is walkable and accessible with good public transportation, fewer people will live in the suburbs, there will be less urban sprawl, and fewer people will buy cars.
 
Compare US Western cities like Denver, Colorado or Los Angeles, California to a city like New York City. While highways and car traffic are important to New York's transportation system, the Big Apple isn't entirely dependent on cars. As a result, the average person in New York City emits 1.37 tons of CO2 per year from transport, while the average person in Denver emits 6.31 tons – more than 4 times as much!
 
As cities in Latin America, Asia, and Africa explode with growing populations, their reliance on cars will be greatly shaped by urban planning done today. If we make smart urban transportation investments (public transportation, mixed-use zoning codes, high density zoning around transportation hubs, pedestrian friendly spaces) instead of traditional ones (more and bigger roads), we'll end up with cities that are easier to live in. Plus, better planning will also reduce green house gas emissions, helping to address one of our greatest global problems.