María Eugenia Flores hops out of a bright yellow capsule halfway down a La Paz hillside and pauses to ponder the benefits of the latest addition to the city’s vertiginous skyline.

Despite views that induce awe – or acute nausea, jittery sweats and the sudden rediscovery of religious faith depending on your tolerance of heights – what impresses her most about the cable car system that now links La Paz and its nearby sister city, El Alto, is its sheer tranquility and cleanliness.

“I used to have to take the minibus to get to work and that was horrible,” says the 37-year-old businesswoman. “The cable car is quicker but, best of all, you don’t arrive at work with a headache from all the traffic fumes.”

The newfound freedom to float safely and quietly over Bolivia’s administrative capital, far above the taxis and gaudy buses that pump black clouds of smoke into the already thin air is cherished by the people of La Paz and El Alto alike.

For Gabriela González, a 21-year-old student from El Alto, the cable car – or teleférico – has provided a welcome alternative to the two or three buses she had to take from home to university in La Paz. With her old, hour-long commute now halved, she has more time to stay in bed.

“It seems really safe, the views are great and it’s really fast,” she says. “I thought it would take ages to build like everything else they promise in La Paz, but they did it really quickly.”

González’s sense of mild incredulity comes as little surprise to the man tasked with delivering the $234m (£149m) scheme.

“People here didn’t believe that, as Bolivians, we could deliver this kind of project,” says César Dockweiler, chief executive of the state-run company Mi Teleférico (My cable car).

“There was an impression that metro systems and the like were only for Europe and the US – not for us – so knowing we can do this economically and technically has created a real sense of pride.”

Seven months after it opened, the cable car system has three lines - yellow, red and green in homage to Bolivia’s tricolor flag - which have to date carried 10 million passengers. On Christmas day alone, they were used by more than 162,000 people.

While he acknowledges that the cable car system cannot compete with a metro when it comes to passenger numbers, Dockweiler says it was the quickest, best and greenest option for La Paz and El Alto, which sit at respective altitudes of 3,650m and 4,510m.

“It’s worth stressing just what a unique city La Paz is: it’s basically in a big hole, so people often go, ‘Who on Earth decided to put a city here?’” he says. “Almost all the space here is covered by houses or roads or squares, so it’s densely populated.”

The network, which cost $20m a kilometre, was built by the Austrian firm Doppelmayr after the government of president Evo Morales decided that cable cars would best suit the unusual urban topography.

Dockweiler, who is carrying out a routine inspection of the system clad in a Mi Teleférico fleece and hard hat, becomes more voluble as he describes how the system went from presidential authorisation to completion in under two years.

“How did we do it? First, there was a very clear political will behind the project. President Morales took the decision and it started to happen straight away. Second, we were very, very thorough when it came to researching and budgeting. Third, we found the right company after checking them all out and seeing which ones deliver on time and on budget – there was a lot of internet detective work. The fourth element was the Bolivian workforce: we had 1,200 people working on it full time and we showed that Bolivians can do this kind of thing.”

There were doubters, says Dockweiler, but they were proved wrong by the speed and passion with which the system was forged. “The Bolivian hands that built this worked day and night, weekends and holidays because they believed in it as a national project.”

It remains to be seen, however, precisely how the advent of Mi Teleférico will affect the cities it links and whether it will narrow the gap between middle class La Paz and the predominantly working class and indigenous El Alto.

A glance around the 10-seater cars reveals a mix of young and old, of traditional, bowler-hatted women and men in suits, and of proud locals and stunned tourists.

“What we want is for the cable car system to create greater integration and unity for people in both cities,” he says. “We want people who live in El Alto to be able to come into the centre of La Paz to eat or to see a film and for them then to be able to get home safely and comfortably. We also want people in La Paz to be able to go to El Alto to enjoy the restaurants and views there.”

Such mingling, he hopes, will yield not just a greater sense of unity and equality, but also help the two cities work together to tackle shared problems such as transport, rubbish, sewerage, landfill and crime.

The system’s flat-rate fare of three bolivianos – or $0.40 – is designed to undercut the cities’ buses and put safe and quick aerial travel well within the reach of El Alto residents who pay five bolivianos to travel to the lower city by road.

But perhaps Mi Teleférico’s greatest appeal in a country where symbolism is as potent as it is ubiquitous lies in its transformative possibilities.

Inaugurated five months before Morales won a consecutive third term in office, the cable car joins other national icons, from the glowering, rifle-clutching statue of Che Guevara trampling an eagle high in El Alto to the clock on the congress building on La Paz whose numerals have been reversed and hands set to run anticlockwise in a defiant display of Andean identity.

“It’s become a symbol of pride and empowerment,” says Dockweiler – and one that will continue to grow.

Although finance is already in place for a further five lines, he believes there could be as many as 16 criss-crossing the cities’ shared skies by 2030.

Asked what the colour options will be given that the hues of the tricolor have already been exhausted, Dockweiler laughs. Bolivia, he points out, is fortunate in also having the multi-coloured, diagonal Wiphala that is shared by Andean nations.

“That means we can have a dark blue line, an orange line, a white line and a purple line, so we’ll see if we can’t use all the colours on that flag too.”