Tijuana's population has grown from about 150,000 in 1960 to almost 1.4 million in 2014. The city's public transportation system has struggled to keep pace with this rapid growth, with multiple transportation firms offering patchy service, often on secondhand American school buses. In this audio slideshow, Patrick Reilly takes a look at these buses and at the new bus rapid transit (BRT) system that's meant to offer a better commute.