Linha 4 Amarela do Metrô (Metro Line 4 Yellow) is the city's newest metro line. Currently running between Luz and Butantã stations, and with stations still under construction, it features futuristic driverless trains which allow passengers a great view front or rear. The project suffered a tragedy in 2007 when, during the construction of Pinheiros station which is particularly deep, the site's tunnel collapsed pulling houses and vehicles into the hole resulting in seven deaths. Tragedy aside, the new route has drastically cut travel times for many thousands of daily commuters, myself included, and for that we're certainly thankful.
