Buses or trams for Latin America's cities?

There was a time when tram services were critical to public transport in many of the largest cities of Latin America; however, trams disappeared about fifty years ago, for a number of reasons. They are back now, especially in the cities of the more developed world, in a modern version usually known as light rail transit. Latin America has developed its own concept of urban mass transit, namely, high-capacity buses operating in special lanes as an integral component of the overall mass transit system. As a general rule, this Latin American solution seems to be the best suited to the needs of the region, given its flexibility, cost and capacity. Each situation must be assessed separately, however, and in some cases, a modernized version of the tramway may be the best solution.