Using electric vehicles (EVs) for public transport is not just plugging in carbon-free power; municipalities also need to prepare for greater wear and tear on roads caused by the heavy batteries EVs need.
Studies in 2023 by London’s Daily Telegraph and the University of Leeds in the UK showed that road damage by EVs is double that of vehicles powered by internal combustion engines (ICEs), because of the weight of the batteries. Leeds researchers found that EVs were on average 312kg heavier than similar ICE versions. In a country as riddled with potholes as South Africa, the interest in converting to EVs needs to be balanced with a smart road maintenance strategy.
Cape Town has taken an approach that considers roads as well as energy efficiency and carbon reduction in converting public transport. In October 2023, the city reported that the results of a three-year EV pilot project case study, conducted by green economy development agency GreenCape, supported the conversion of municipal vehicle fleets to EVs.
Rob Quintas, member of the mayoral committee for urban mobility, tells the FM the city is taking a “conservative approach” in which the additional weight of EV buses has been taken into account at the procurement phase. “At this stage, the city’s corporate fleet management is the only department that has piloted the use of EV vehicles,” he says. The rollout of EV buses is expected to take place in the second half of 2027.
Quintas says road longevity is subject to several factors besides loading magnitude, which depends on vehicle axle loads and the number of load repetitions that a road must support. These other factors include the quality of road construction, the materials used, water penetration and preventive maintenance.
Studies in 2023 showed that road damage by EVs is double that of vehicles powered by internal combustion engines
“Our red roads are continuously reinforced concrete,” he says, referring to the lanes used exclusively by the MyCiTi buses. So far, “apart from some strengthening at some of the intersections, the traffic loading imposed by the electric buses has not significantly changed the design and, by implication, the design life”.
Quintas refers to Cape Town’s road network — close to 10,700km — as “one of our biggest assets … we have allocated R2.6bn of the directorate’s operational budget over the next three years to road maintenance”.
The city’s feasibility study considered a range of alternative power sources, including compressed natural gas (CNG), hydrogen electric, battery electric and hybrid. It also took into account Euro VI limits on emissions for new cars and commercial vehicles sold in Europe.
“Key recommendations from this study advocate for the adoption of a dual strategy, involving the acquisition of both Euro VI diesel buses and battery electric buses for the upcoming procurement cycle for the rollout of the second phase of the MyCiTi bus service,” Quintas says.
Initial capital costs, as well as the cost of infrastructure and battery replacement during the life cycle of electric buses, were expected to be “considerably [higher] than that of a diesel bus. However, the maintenance and energy costs are significantly cheaper,” he says.
In GreenCape’s “Electric Vehicles Market Intelligence Report” for 2024, average procurement prices for EV buses and minibuses (at up to R8.1m and R1.5m respectively) were given as more than double that of their ICE counterparts (at R2.7m and R680,900). But the operational costs of EVs per 100km were R227.70 and R115, compared with R966.40 and R241.60 for ICEs. Average annual mileage remained the same for both categories. GreenCape’s calculations for fluctuating diesel prices are updated annually. While current prices were accurate at the time of publishing, they do not reflect the latest price updates.
Quintas says once the plan for EV public transport is rolled out, “the city will keep on investigating alternative fuel options given the continuous technology changes within the zero- and low-emissions industry … to ensure the city procures the best available technology at the time of procurement”.
In November 2022 the national department of transport released a Green Transport strategy presentation for 2018-2050, “to convert 5% of the public and national sector fleet in the first seven years of the implementation of this strategy and an annual increase of 2% thereafter, to cleaner alternative fuel and efficient technology vehicles (ideally powered through renewable energy) and environmentally sustainable low carbon fuels by 2025, including the use of CNG, biogas and biofuels and the use of renewable energy to provide electricity for transport”.
Questions to the South African National Roads Agency Ltd on plans to mitigate the possible impact of EVs on national road infrastructure did not receive a response.
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