Your likely image of Mexico City traffic is one of immobile gridlock, an intractable smog haze, fire-eaters at traffic lights. It’s true enough — it’s what I saw on a trip there — but it’s out of date. Consider the formula: 18 million people, 6 million cars, and 600 new vehicles hitting the streets every day. Public transit was an unavoidable adventure.

Here's a resident talking about the way public transit used to be: "At peak hours and on weekends between jostles and shouts from mobile vendors, breathing is difficult, but even so, public transportation is something our children should know. It's part of their reality. It's part of their city."

But believe it or not, Mexico City — which had the worst score on an IBM “driver pain” index as recently as 2011 — is on the mend. Last year, it actually had 248 days with “good” air quality. Traffic is easing. It’s becoming “Mexsicko City” no more.

Mexico City’s woes have been compounded by geography, because it’s in a trapped high-altitude valley that concentrates pollution. In 1992, it had just eight good air days. It was better not to breathe outside in Mexico’s capital, and the problem appeared beyond a practical solution.

Riding on a bus in Mexico City

Only it wasn’t. The New York Times reports, “Mexico City has emerged as an aspiring environmental model citizen in recent years as the left-leaning local government has introduced everything from barter markets for recyclables to bicycle-sharing arrangements to zero-emissions bus corridors.”

Mexico City (which is also benefiting from a lower birth rate) committed $2 billion to ease the traffic problem, and it ramped up its collaboration with a useful nonprofit called EMBARQ, which works (in Brazil, China, India, Turkey and the Andes as well as Mexico) on sustainable transportation solutions. So a year after coming in last in IBM’s driver study, the city won a Sustainable Transport Award. Here’s what they did.

Graphic breakdown of Mexico City's traffic

It starts with bus rapid transit, which has turned the city of Curitiba, Brazil, into the poster child for sensible urban traffic control. Some 70 percent of Curitiba’s commuters travel on buses that travel in dedicated and otherwise traffic-free corridors (see photo below). Mexico City’s system, Metrobus (supported with a $49 million World Bank grant), launched in 2005, and has expanded rapidly (including to the airport), and now serves 315,000 passengers a day (about half the number who ride Washington, D.C.’s Metro system). If you want to use a major artery to get into the historic downtown area now, you either ride a Metrobus or walk.

Graphic of Metrobus use in Mexico City

Each year, Metrobus (which operates a fleet of hybrids and Euro V clean diesels with 95 percent less particulate emissions than earlier buses) cuts nitrogen oxide emissions by 690 tons, particulate by 2.8 tons, and hydrocarbons by 144 tons. According to EMBARQ, the bus rapid transit (BRT) system has improved mobility by 50 percent, cut accidents by 30 percent, and moved 6 percent of travelers from private cars to public transportation.

There’s more: A bike-sharing service called Ecobici is popular enough to have developed a waiting list. The city also developed the “Hoy No Circula” program, which limits the travel of older, pre-2005 cars and trucks. Tougher emission laws were also introduced and — critically important — protected against endemic corruption.

traffic-free corridor in Mexico City

Minister of Environment Tanya Müller Garcia says the bike program is definitely having an impact on Mexico City’s pollution levels. “The number is quite shocking,” she said. From the start of the bike program in 2010 to 2011, some 105 tons of carbon dioxide emissions were avoided.

There’s even a parking meter pilot program called ecoParq, designed to reduce the amount of time cars spend circling in search of a free spot. The city’s subway system, which has suffered from over-crowding, was recently expanded with a nine-mile “Golden Line.” And people are switching to the Metrobus, because according to EMBARQ it can cut a two-hour trolley ride to 55 minutes. Here's EMBARQ on video, explaining how it's done:

It looks like we’ll have to revise our preconceived notions about one of the world’s most populous third world capital cities. There’s still lots to be done, but Mexico City is on a roll.

Related post on MNN: 7 cities that rallied after natural disasters

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.

A greener Mexico City tries eco-transit
mexico city public transit