According to a new study, adding bike lanes to urban roads can increase the number of cyclists in an entire city, not just on the streets with new bike lanes. The result contributes to a growing body of research suggesting that investing in bicycle infrastructure can encourage more people to commute by bicycle, which will help reduce greenhouse gas emissions and improve health.

“It’s the first evidence we’re trying on a larger scale to connect bike infrastructure – those pop-up bike lanes and the built things – to bike levels during Covid,” said Ralph Buehler, chairman of urban affairs and planning at the school of Public and International Affairs at Virginia Tech, which was not involved in the study.

The study, published online Monday in the Proceedings of the National Academy of Sciences, found that cities where cycling infrastructure was added saw cycling up as much as 48 percent faster than cities where bike lanes were not added were.

Dense cities where public transport was already popular tended to see the greatest increases. In cities with lower density, more cars per capita, and higher traffic speeds, the increase in cycling was more modest. Paris, which launched its cycle path program early and had the largest pop-up cycle path program of any city surveyed, saw one of the largest increases in riders.

“It almost seems like a law of nature that the more infrastructure you have, the more cycling you have,” said Sebastian Kraus, the study’s lead author.

Updated

April 1, 2021, 7:58 a.m. ET

However, in research on public transport, the impact of adding bike lanes is controversial.

“It’s like a chicken and egg problem,” said Kraus, a doctoral student in economics at the Mercator Research Institute for Global Commons and Climate Change in Berlin. “There can be this reverse causation that if you have a lot of cyclists, they actually require better infrastructure, and it’s not really the infrastructure that creates more cycling.”

The researchers collected data, including the length of new bike lanes and data from bike counters, from 106 cities across Europe. At the bike counters, the researchers were able to measure the number of cyclists across the city, not just on the new bike paths. They analyzed the number of cyclists from March to July and found that cities where bike lanes were added, cycling increased by 11 to 48 percent more than cities where no bike lanes were added.

The researchers found that the increase was seen in the control of weather and changes in the supply and demand of local public transport.

In contrast to cars, bicycles do not emit greenhouse gases. Matthew Raifman, a PhD student in environmental health at Boston University School of Public Health, found in a separate study that investing in infrastructure for cycling and walking has more than paid off given the health benefits.

“They increase our physical activity, reduce greenhouse gas emissions and improve air quality, all of which have an impact on health,” said Raifman.

Mr Kraus warned that the results of his study only apply to the pandemic as public health officials encouraged cycling to reduce the risk of coronavirus transmission and cities around the world added cycling infrastructure to their roads. But it might not be difficult to imagine that more people could keep cycling after the pandemic ended.

Research on strikes in transit has shown that forcing you to experiment with new routes and modes of transit can lead to new routines.

“There are indications from mobility behavior research that you could actually stick to it as soon as you find another way to get around,” said Kraus. “So I’m confident that if you keep the infrastructure, people will keep cycling.”