Driverless cars – autonomous vehicles – are coming. The topic is a constant presence in media; The New York Times Magazine recently devoted most of an issue to it.
The technological imperative is strong: if we have the technology, we have to use it. The economic imperative is even stronger. Many industries see big dollar signs. Governments want to be somewhat cautious, but they don’t want to be left behind.
The sales pitches are becoming clear: driverless cars will free drivers to do other things; driverless cars will reduce congestion because they can travel closer together; driverless cars will create massive economic opportunities.
We are also told driverless cars will be much safer, because human error causes more than 90% of crashes.
Understanding how cars affect our health
Human-operated cars affect health in three main ways, all negatively. How might driverless cars be healthier?
Safety improvements will depend on the technology in the cars, which is currently being developed and tested. Safety also depends on how the surrounding environments are engineered or re-engineered to keep people and things from darting in front of driverless cars.
Second, cars kill people by creating pollution. Cars with internal combustion engines produce gases and particulates, which cause lung disease. Motor vehicles are also one of the biggest sources of carbon dioxide worldwide, which causes climate change.
The polluting effects of electric cars depend on how the electricity they use is generated. Thus, the pollution-related benefits of driverless cars depend on the mix of petroleum-powered versus electric-powered vehicles.
This mix is difficult to predict and likely to differ by country. The pollution effects of driverless cars will also depend on whether they travel more or fewer total kilometres than today’s cars.
Third, cars kill people because we sit while we drive, reducing healthier modes of transport like walking, cycling, or even taking public transport. Public transport is a healthy mode of travel because people generally have to walk or cycle to, from and between stops and stations.
Little physical activity and too much sitting independently contributes to the chronic diseases that kill most people in the world. Those diseases are usually heart diseases, strokes, multiple cancers, and diabetes.
Driverless cars will do nothing to reduce the effects of cars on chronic diseases unless they are introduced in a way that reduces the time people spend sitting in cars.
More than 90% of the negative health impacts of cars result from the effects on physical activity, sitting, and chronic disease.
For example, modelling found that if 10% of motorised transport in Melbourne was shifted to walking or cycling, improvements in disability-adjusted life-years for every 100,000 people (an indicator of quantity and quality of life) would be -34 (worse) for road trauma (mainly because cyclists might not be protected from cars), +2 for lung diseases, and +708 for the combination of heart diseases and type 2 diabetes.
Models for five other cities (Boston, Copenhagen, Delhi, London and Sao Paulo) supported the same conclusion.
Virtually all of the health impacts of cars are due to increasing risks for very common chronic diseases. Therefore it will not matter if people are sitting in driverless or people-driven cars.
One of the implications of these findings is that the people planning for driverless cars should explicitly consider the health consequences of driverless cars. Injuries from crashes and air pollution are routinely considered in transportation planning, but impacts on physical activity and chronic diseases are not.
Further reading: How do we restore the public’s faith in transport planning?
Transportation planning goals and methods need to incorporate chronic disease impacts generally, but especially when planning a major disruption like accommodating driverless cars. Ideally, public health professionals will be at the table as questions are asked and decisions are made.