(1)Consultant, TRENMO Engenharia SA
(2)Associate Professor, Faculty of Engineering of the University of Porto & Research Centre for Territory, Transport and Environment
Dozens of cities have integrated urban cable cars into their public transportation networks. Advantages of cable cars include fast implementation, relatively low construction costs and environmental impact. However, due to the negative public perceptions, cable cars remain a sensitive subject.
For decades, vehicles used in urban mobility were limited to trams, metros, buses, cars, bicycles, and ferryboats, while the sight of cable cars was reserved for mountain peaks. Recently, cable cars have been integrated into urban areas as ‘urban cable cars’. This is a relatively new addition to public transportation modes, with the first urban cable car inaugurated in 2004, in Medellin. Since then, dozens of cities worldwide have introduced cable cars.
In the mid-80s, the travel demand between La Paz and El Alto was identified as the highest in the Metropolitan Area of La Paz. Given the difference of 420 meters, a cable car system was suggested. However, the network was designed only in 2012, and the construction was finished in 2014. Once completed, the cable car in La Paz has shortened travel time by 70 minutes connecting the richer city of La Paz with the poorer one in El Alto (Martinez et al., 2018). Currently, the city’s cable car network includes 10 lines with 36 stations, and a total length of 30.60 km. In 2018, La Paz won the Guinness World Record of the largest cable car system in the world (Martinez et al., 2018).
Besides geographical reasons, the choice of adding cable cars into urban landscapes rather than a railway system has other benefits. The biggest drivers in opting for cable cars include relatively low construction costs, minimum changes to the urban structure, and significantly low environmental impact. The traditional metro project generally requires land acquisition, urban changes, and lengthy and costly construction works, and even then, the possibility of running into cost overruns that lengthen the project implementation and delivery is quite usual.
In environmental terms, cable cars are less harmful to the environment than the traditional railway-based transportation systems. While the operation of metro and light railway transit can be achieved without emissions, the construction phase causes high greenhouse gas (GHG) emissions. The average reported emission of a tunnelled railway line is 20 695 tCO2 per kilometre line, whereas at-grade constructions cause 1 400 tCO2 per kilometre line (Olugbenga, Kalyviotis, & Saxe, 2019). Due to the difficulties in securing the required at-grade space for railways in urban areas, and the desire for a minimal disruption to the urban structure, tunnelled options are more common than at-grade constructions. Respectively, the emitted amount of GHG emissions from the construction of one kilometre of a tunnelled railway is equivalent to 1 million journeys, wherein each journey extension is 150 km, made by private cars, or half a million private car journeys between Lisbon and Porto. Once the built line replaces the corresponding number of journeys made by private cars, or other fuel-based public transportation means, that’s when the metro or LRT line becomes worthwhile in environmental terms. In comparison to tunnelled railway systems, emissions from cable cars are insignificant.
Additionally, the implementation time of cable cars is relatively short. In Medellin, each of the three lines, K, J, and L, extending between 2 km and 4.5 km, was completed within 10-15 months (Dávila & Daste, 2013). In La Paz, the completion of three cable car lines with a total of 10 km in length was also finished in less than three years. Considering the limitation of 3-5 years in the office for a mayor or a Prime Minister, successfully completing a transportation project that would lead to significant improvements in quality of life is appealing to politicians.
In the midst of climate change concerns, the cable car solution offers not only an overall prompt reduction of GHG emissions after its construction, but also fast implementation.
After considering these advantages, it is not surprising that hilly cities are not the only ones contemplating the addition of cable cars into their landscapes. In 2016, Greater Mexico City introduced Mexicable on a busy road in Ecatepec. In comparison to the road transportation, Mexicable shortened the journey time by 17 minutes. In 2016, Brest became the first French city to adopt urban cable cars. Providing a connection between two sides of Penfeld River, the Brest Cable car was built with the intention of relieving the congestion on the city’s two bridges. In the opening ceremony, the French environment minister praised cable cars as “…the solution of the future to reduce pollution on the planet” (DW, 2016).
Initially launched in developing countries, there are more and more politicians worldwide considering cable cars as a solution to urban mobility problems in their cities. Politicians are entitled to protect scarce resources including land, and non-renewable resources, as well as public money. Considering these concerns, cable cars seem to be a comparably better alternative to the traditional modes of travel. While some developing countries have paved the way on integrating cable cars into the city’s public transportation network, the idea of cable cars in urban areas is still unacceptable to the general public, especially in the developed countries. Despite conceptual solutions, technological advancements, and design improvements, passenger experience including fear of heights, and cable car’s interference with the urban aesthetics make this means of transportation a sensitive subject for the public perception.
Given the advantages, is it possible to overcome the public backlash against cable cars over aesthetical issues for the sake of sustainability?
References
Dávila, J. D., & Daste, D. (2013). Pobreza, participación y Metrocable. Estudio del caso de Medellín. Boletín CF+ S, (54), 121-131.
Deutsche Welle (2016). France’s first urban cable car opens for business in Brest. Deutsche Welle, 19 November 2016. [Accessed on September 2022]. Available on: https://www.dw.com/en/frances-first-urban-cable-car-opens-for-business-in-brest/a-36452689.
Martinez, S., Sanchez, R., & Yañez-Pagans, P. (2018). Getting a lift: The impact of aerial cable cars in La Paz, Bolivia. IDB Working Paper Series, No. IDB-WP-00956.
Olugbenga, O., Kalyviotis, N., & Saxe, S. (2019). Embodied emissions in rail infrastructure: a critical literature review. Environmental Research Letters, 14(12), 123002.