London's inauguration, in 1863, of the world's first subway was quite literally a groundbreaking development. Since then, cities across the globe have followed suit and gone all-in on underground public transportation systems. Still, the question remains: Just how worthwhile are they?

Developed countries like Germany, China and the United States each have more than 15 cities with successfully developed subway networks, while Spain has metro systems for eight of its cities. The big industrial countries thus have a solid network of metropolitan railways, in part because of increasing sprawl in their cities.

Subways can be indispensable in large cities (those with upwards of one million residents) where services are concentrated in central districts and surface mobility is difficult. Not only do they provide a much needed public transport service, but metro systems are also, in those circumstances, cost-effective, since they need at least 10,000 travelers per hour (in either direction) to cover their high upfront investment costs.

There also also considerable social benefits: Metros improve mobility for everyone, cut harmful emissions by reducing car usage, and help free up surface spaces for city dwellers to enjoy. All of this, in turn, helps boost economic activity and productivity.

In Latin America, many of the region's big cities are familiar with these benefits, as evidenced by a gradual trend over recent decades to implant urban rail networks. The oldest — the iconic Subte, in Buenos Aries — has been around for more than a century. The Mexico City metro, which carries 1.7 billion people every year and began operating in the late 1960s, is another exemplary system, as are the metros in Sao Paulo (Brazil) and Santiago (Chile), which date back to the mid 1970s.

Subte in the Argentine capital is the star subway in Latin America — Photo: Rodrigo Quezada

The 1980s were something of a "lost decade" for subway building — only Caracas inaugurated a system — but metro plans have picked up again since the turn of the century. Lima (Peru), Panama City (Panama), Salvador de Bahía (Brazil) and Santo Domingo (Dominican Republic) are just some of the cities that have inaugurated rail systems in recent years. In the meantime, the most established and widely used networks, like those in Mexico City, Santiago and Sao Paulo, have added lines, with all signs pointing to even more expansions in the future.

Pollution, traffic jams and enhanced environmental awareness, and the positive track records these systems have shown so far (once the construction nuisance is over) have convinced policymakers that metros, while expensive, are excellent, sustainable investments that enhance the mobility and lives of their constituents.

Next stop... Bogota

Perhaps nowhere has the need become more painfully obvious than in Bogota. With 8 million residents and limited space for developing new urban zones, the Colombian capital is desperately in need of a solution to its considerable mobility problems. Over the past 30 years, Bogota's population has grown more than 90%. And the impact of all that growth is visible and palpable every day in the city's endless and starling traffic jams.

The city is responding with plans for an above-grand light rail that will operate in conjunction with its already existing regular bus system and soon-to-be-expanded TransMilenio (fixed track buses) system. While these projects have so far developed separately, the city is working now on a more coordinated public transportation policy that includes all relevant actors.

The city government's transport office recently compiled a study on how transportation could evolve in the next 14 years. It found that by 2030, residents would make 10.5 million trips a day, which translates into a daily demand for the metro of 960,000 passengers — more than enough to justify construction.

The city hopes, by then, to have 25 trains, and perhaps doubled soon afterwards. These will serve 15 stations along the 31 kilometers of the metro's Line One, set to link southwestern Bogota (Portal de las Américas) to the northeastern residential districts (Caracas Avenue at 72nd Street). Line One will thus become a broad, north-south axis functioning on an elevated structure (a solution imposed by terrain geology) 12 meters above ground. Trains will run at a maximum speed of 41 km per hour along tracks measuring 1.435 meters (international track gauge).

The project's estimated cost is over $13 billion, with inauguration scheduled for 2022. A study commissioned by the Inter-American Development Bank and the professional services firm Deloitte found that the Bogota metro could bring major economic benefits for the city, including a drop in the cost of personal mobility, savings due to reduced greenhouse gases and fewer road accidents, as well as a huge reduction in the time people spend traveling (up to a billion hours saved by 2052). Commuting in the Colombian capital, it seems, will never be the same again.