The city of La Paz in Bolivia provides a good example of how the improvement of public transport can be beneficial for its citizens, the environment and tourism. La Paz has around 800.000 inhabitants and is located in a steep valley. At the edge of this valley, at 4000 m altitude, its suburbs expanded quickly over the Altiplano (high flat) and grew into the sister city El Alto. It is estimated that El Alto has now around one million inhabitants. For their public transport the two poor cities used to rely only on old school buses from the USA and Asian Mini Vans. With so many people living and working in La Paz and El Alto and only limited access to travel in and out of the valley, traffic jams and chaos on the roads was very common.
Former president Evo Morales wanted to solve these traffic problems and together with a Swiss company he started the construction of a cable car network (Teleférico in Spanish). The first (Red) line started operating between La Paz and El Alto in 2014. Now there are already eleven lines with different colors, connecting many different locations in La Paz and El Alto. Because the Teleférico is so well connected, saves travel time and is very affordable (3 Bolivianos, around 0.40 USD each ride) it has become a popular form of public transport and has improved the traffic situation. In 2019 the Teleférico received its 200 millionth customer, a sixty year old indigenous Ayamara women traveling the Red Line. But besides being just a form of public transport, the Teleférico also became one of one of the main tourist attractions of La Paz.
Personally I can highly recommend taking at least the Red Line from La Paz to El Alto. Then a motor taxi to the station of the Yellow Line in El Alto and use this line to travel down into the city center of La Paz. The views of the snowcapped Illimani Volcano and the Cordillera Real around La Paz are amazing!