Electric bike or electric car? How our mobility choices will impact public health

Léo Moutet, Aurélien Bigo, Kévin Jean, Laura Temime, Philippe Quirion, December 2024

The Conversation

The transport sector, which accounts for one-third of greenhouse gas (GHG) emissions in France, plays a crucial role in the ecological transition that must be implemented to address climate change.

Among the solutions for decarbonising transport, i.e. limiting the use of fossil fuels, active transport, which includes walking and cycling (both conventional and electric), stands out for its health benefits.

These modes of transport not only help improve air quality and reduce CO2 emissions, but also encourage regular physical activity. From an individual perspective, someone who replaces their car with a bicycle for their daily commute for 200 days can reduce their CO2 emissions by 0.5 tonnes per year, while enjoying numerous health benefits.

We have assessed the health impact of the four transition scenarios proposed by the French Agency for Ecological Transition (ADEME).

Five levers for reducing transport emissions

In 2021, the French Agency for Ecological Transition (ADEME) presented the results of the Transition(s) 2050 project, which explores four scenarios for achieving carbon neutrality by 2050 in mainland France:

• S1 (‘Frugal generation’);

• S2 (‘Territorial cooperation’);

• S3 (‘Green technologies’);

• S4 (‘Repairing bet’).

Each scenario is based on distinct societal choices, illustrating different possible paths towards a decarbonised society. All describe the evolution of the main factors influencing energy and material consumption, in particular transport demand, which includes active modes. These estimates also take into account the distances travelled on foot to access public transport.

In parallel, a trend scenario extends current societal trends without achieving the carbon neutrality objective (BAU scenario, for ‘Business As Usual’).

In this forward-looking exercise, five levers are used to reduce transport emissions (reducing transport demand, shifting to lower-emission modes, increasing vehicle occupancy, increasing energy efficiency and decarbonising energy production), with each scenario activating the various levers in order to meet the transport demand of the population by 2050.

Where S1 and S2 focus more on efficiency levers through demand reduction, modal shift and better vehicle occupancy, S3 and S4 rely mainly on technological levers for energy efficiency and decarbonisation of energy production.

In our study, we modelled the health effects of active transport in France under the Transition(s) 2050 scenarios, based on the quantitative health impact assessment method.

Improved health

Taking into account the current distribution of active transport by age group, we estimated the health benefits, such as the number of deaths avoided and the years of life gained by the population.

Changes in demand for active transport between 2021 and 2050 show distinct trends depending on the scenarios explored. In 2015, active modes of transport in France generated an average of 80 minutes of moderate physical activity per person per week.

Under scenario S2, these levels reach 150 minutes per week from 2035, which is equivalent to the World Health Organisation (WHO) minimum recommendations for physical activity. Scenario S1 achieves this only 15 years later, in 2050.

However, scenario S3 remains insufficient to achieve these objectives. Scenarios S4 and the trend scenario (‘business as usual’, i.e. no change from current trends) predict limited changes in active transport. These results, broken down by age group, illustrate uneven trajectories for promoting physical activity in France.

Depending on the scale of the modal shift, the projected health impacts, regardless of age, vary considerably and increase over time. By 2035, 19,000 deaths could be avoided if scenario S2 is followed. Conversely, if scenario S4 is chosen, 2,000 additional deaths (attributed to a decrease in walking) could be recorded each year compared to the trend scenario.

These health indicators can be translated into life expectancy for the population: in both cases S2 and S4, it could then increase by 3 months or decrease by 0.2 months, respectively.

A largely positive risk-benefit ratio

To accurately assess the health consequences of modal shift, it is crucial to consider certain additional factors, such as exposure to air pollution and the risk of road injuries (particularly for cyclists).

In our study, these impacts are considered indirectly in the calculation, as it is based on ‘all-cause’ mortality.

Furthermore, various studies have shown that the absolute benefits of physical activity generated by active transport far outweigh the negative effects of exposure to pollution or road accidents during physical activity.

Thus, in general, exposure to air pollution tends to be lower for public transport users and cyclists than for motorists, while pedestrians are exposed to the lowest levels.

As for cycling accidents, they are expected to decrease with increased use, a phenomenon known as ‘safety through numbers’.

Indirect benefits

Beyond the direct health benefits, increasing the modal shift in urban centres would also help reduce noise pollution, thereby improving residents’ sleep quality.

Furthermore, dedicating more space to cycling infrastructure, particularly by limiting the space allocated to cars, and encouraging a shift towards active modes of transport also optimises the use of public space.

Finally, physical activity also improves quality and performance at work, thereby enhancing employee well-being and productivity.

Achievable targets

In all the scenarios studied, the majority of health benefits come from a significant increase in cycling, particularly thanks to the rise of electric bikes.

The most optimistic scenario envisages that by 2050, each French person will travel an average of 20 kilometres by bicycle and 7 kilometres on foot per week, representing approximately 20 minutes of moderate physical activity (walking and/or cycling) per day, compared with 11 minutes in 2015. Although this increase is significant compared to pre-2020 levels, it remains below that seen in other European countries.

In the Netherlands, for example, active transport already accounts for between 24 and 28 minutes per day, with more than 50% of journeys of less than 2 kilometres made by bicycle. In France, only 5% of the population uses a bicycle for journeys of less than 5 kilometres, while 60% choose to travel by car.

If the government’s roadmap (National Low-Carbon Strategy) remains on track, physical activity generated by cycling could prevent around 5,000 deaths in 2030 (compared to 2019 levels).

However, achieving the current cycling levels of our Danish and Dutch counterparts by 2030 would double and quadruple these benefits respectively.

These figures highlight the potential for improvement in our country and confirm that the levels projected in scenarios S1 and S2 are entirely achievable.

The evolution of cycling practices could therefore be more ambitious, as shown by the analysis of cycling frequency data in certain cities.

Encouraging active transport: where to start?

Among the levers known to be effective in encouraging active transport is the improvement of urban planning. Improving accessibility and providing safe infrastructure promotes these modes of transport.

In addition, when suitable infrastructure exists, the high cost of car ownership encourages users to abandon their cars in favour of walking or cycling.

The health benefits of cycling are considerable and can also encourage decision-makers to implement public policies to promote cycling. They can even convince the population to convert to cycling.

Unfortunately, although the government had promised an ambitious €2 billion cycling plan for 2023, with a particular focus on rural and peri-urban areas, this seems to have disappeared from the 2025 budget.

Local authorities that have committed to cycling policies could see an essential financial lever disappear. If the measures essential to the transition to a more resilient society were to be undermined, this would have consequences for both the environment and health.

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