Do bike lanes really cause more traffic congestion? Here's what the research says

The subject of bike lanes can be a contentious one, particularly in a busy city like Toronto. Last week, the Ontario government proposed legislation that would require municipalities to get provincial approval to install any bike lanes that would remove a lane of vehicle traffic, which resulted in a firestorm of debate and protests. 

The legislation was introduced on Monday.

While advocates look at dedicated bicycle lanes as encouraging more people to travel by bike — resulting in less traffic congestion, safer commutes for cyclists and reduced greenhouse gas emissions — some motorists blame them for causing more congestion.

But research shows that dedicated bicycle lanes are not behind perceived traffic congestion and can have many benefits.

One would think that building more roads with more lanes for cars would reduce congestion, but research shows that's not the case, thanks to something called induced demand. The more traffic lanes that are put in, the more it appeals to people who may not otherwise have chosen to drive, thereby putting more cars on the roads and increasing congestion. 

"So for a short period of time, there might be a slightly improved [reduction], but within a year or two, or perhaps three, traffic is as bad or worse than it was before the lanes were added in the first place," said David Beitel, data services lead at Eco-Counter, a Montreal company that collects and analyzes pedestrian and bicycle traffic data.

Conversely, if you put in more dedicated bike lanes, people tend to feel safer and demand for use increases, said Shoshanna Saxe, an assistant professor at the University of Toronto's department of civil and mineral engineering and Canada Research Chair in sustainable infrastructure.

"As soon as you build a bike lane, within a year, two years, the latent demand shows up," she said.

Bike Share Toronto statistics show that ridership on its network of shared bikes has increased dramatically since 2015, when 665,000 bike trips were made annually. In 2023, that shot up to 5.7 million trips.

In 2016, the European Commission's CIVITAS program published a study examining traffic congestion that looked at several cities around the world.

For example, in New York City, the authors shared figures from the city's transportation department that showed in 2010, before bike lanes were installed on a major midtown thoroughfare, it took the average car 4.5 minutes to travel from 96th Street to 77th Street. After the bike lanes were installed, it took just three minutes — a 35 per cent decrease. One of the reasons they cited for the change was the installation of a left-turn lane, which not only kept cyclists moving but also stopped cars from holding up traffic.

In Copenhagen, which introduced its first "green wave" meant to encourage cycling in 2007, the city reported that "the large number of bicycles, for example, makes it easier for necessary basic motor transport such as tradesmen, goods transport and buses to get through more easily." In fact, there is so much bike use that the city has had to add more bike corridors to cut down on bicycle congestion.

Other case studies found either no impacts on traffic, or minimal delays — anywhere from a few seconds to just over a minute.

Then there's Paris. The city saw a 54 per cent increase in bike use from 2018 to 2019. And for the first time, car use decreased by five per cent between 2010 and 2018.