A study of 167 European cities lays out the positive effects—and limits—of investing in more cycling infrastructure.
European cities could reap huge rewards for building out their cycling infrastructure, but perhaps no incentive is as important as this: By expanding bike networks, they could prevent 10,000 premature deaths each year.
That’s the finding from a new European Commission-funded study by the Barcelona Institute for Global Health that seeks to assess the relationship between cycling’s popularity and death rates. The findings, compiled from 167 cities and published in the journal Preventive Medicine, are striking. If 24.7 percent of all journeys were taken by bike, London could see 1,210 fewer premature deaths annually, Rome could see 433 fewer, and Barcelona could see 248 fewer. Spread across the entire network of cities investigated, that’s a substantial drop in mortality. But how exactly could cycle network expansions make this happen?
Improving bike infrastructure (thus boosting cycling’s modal share) can reduce urban deaths by three key factors: air quality, public health, and collisions. By encouraging more people to switch from other forms of transit (other than walking, whose modal share the study predicts would remain stable), installing more bike lanes increases physical activity and provides health benefits. This modal shift slashes the volume of particulate-emitting vehicles on the road, meaning the air people breathe is less damaging to their health. And finally, as the modal share for motor vehicles drops, the number of people these vehicles kill in collisions drops off.
Reduced premature death rates are a destination anyone would want to reach, but getting there can be costly. To get 24.7 percent of journeys carried out by bike, the report estimates that cities need 315 kilometers of bike lanes per 100,000 inhabitants. In effect, they would need to install a lane on every road. As for how much that would cost, the report finds that in the Netherlands, every new kilometer of bike lane costs around €2 million (that might sound high, but it includes the cost of remodeling an entire road, rather than just laying paint for a bike lane). For cities with rudimentary bike lane networks, making the infrastructural leap could require a very large injection of cash. London’s current bike modal share is just 3 percent of all journeys, Barcelona’s is 2 percent and Rome’s only 1 percent. In cities like these, the cash needed to jump to 24.7 percent would be huge.
Thankfully, this money could be more than recouped, the study finds. By reducing premature deaths through improvements in air quality, public fitness, and a drop in fatal road collisions, the benefits of a larger modal share more than outweigh the costs—quite strikingly so, in some cities. If Rome increased its cycling modal share by even 10 percent of its current level—still a major improvement—it could save €70 for every euro spent on bike lanes. Barcelona could save €35 for every euro spent on infrastructure, and London could save the pound equivalent of €8 for every euro spent.
So how far should this investment go? Intriguingly, the study finds that there is an upper limit to the effect that constructing bike lanes can have on increasing cycling’s modal share—and notes that the most dramatic improvements happen at the lower end. When a city has very few bike lanes, installing more can produce a striking increase in cycling. This is why Rome could make such large cost savings from expanding its network—because its lanes are so rudimentary that even a modest expansion could flush a substantial number of cyclists on to the streets.
Once a city’s cycling modal share reaches over a quarter of all journeys, however, more lanes won’t necessarily yield the same results. The study found this by looking at Antwerp and the Swedish city of Örebro, both cities with unusually healthy proportions of cyclists on their streets. While Örebro had over 2.5 times more kilometers of cycle lanes per inhabitant than Antwerp, its cycling modal share of 25 percent of all journeys was only slightly higher than Antwerp’s, which stands at 23 percent. If there is an upper limit after which more lanes make little difference, Antwerp seems to have reached it.
It’s important to be clear what this upper limit signifies. It in no way means that the 25 percent mark is the maximum that any city’s potential bike modal share can reach. Indeed, Copenhagen and Amsterdam have reached far beyond this point. What is does mean, however, is that after the 25 percent modal share mark has been breached, cities seeking to get even more people on bikes might want to focus on other measures instead, such as banning cars or substantially reducing the road space allotted to them.
This is intriguing for cities who already see more than a quarter of all journeys taken by bike. Even in Europe, however, this group remains small. In cities such as London, the push to increase the number of bike lanes is a constant fight—albeit one more fought against a reactionary media than against the public at large. To the decision-making powers in some municipalities, they can be an attractive but costly distraction from the real business of keeping a city housed, healthy, working, and on the move.
This report provides a valuable response to this position. It shows that good bike infrastructure is in fact an integral part of keeping a city functioning—not only keeping transit fluid, but also reducing the burden on health services and making urban spaces altogether cleaner and more livable.