Data-driven bike lane planning
For years, cities have expanded their cycling networks in response to growing demand. But figuring out exactly where new bike lanes should go has often relied on simplified planning methods, public pressure, or political compromise.
Prof. Sheng Liu, an author of a new study highlights the main issue with this approach. “Ignoring traffic dynamics when designing bike lanes can needlessly worsen congestion,” he said. And sometimes, without a solid plan in place, the expected uptick in cycling just doesn’t happen.
Now it seems there may be a better way of doing things. Working with two other academics from University of Toronto, they pulled data and talked to city planners in Vancouver and Chicago to develop a model that helps municipalities choose optimal locations as they expand their cycling lane networks.
“Our model provides a systematic decision-making tool for municipalities to design new bike lanes using existing data. It helps policymakers better quantify and evaluate the potential benefits and risks of bike lane construction. In particular, it can predict whether and where traffic will get better or worse and if emissions will go down,” said Liu.
Increased cycling, shorter travel time, lower emissions
The new model uses a city’s real traffic and commuter mobility data to predict how both cycling and driving will change depending on where new lanes are placed. It estimates changes in driving travel times based on traffic volume, road features, and bike lane locations. It also predicts how attractive a route will be to cyclists versus drivers.
By analysing all of these factors, the model suggests which roads will get the most cycling use and cause the least congestion if bike lanes are added. The researchers applied the model to one of the most traffic-congested cities in the US, Chicago. This city faces the same challenges as other urban centres, balancing road space between cars and bikes without making traffic worse.
Their model made promising predictions. Adding 40 km of bike lanes would increase downtown cycling ridership from 3,6% to 6,1%. Meanwhile, driving times would go up by no more than 9,4%.
“As bike lanes expand, some roads may observe more congestion, and some roads may actually see improved traffic. On the network level, we find that the overall travel time for all commuters is shorter under the proposed bike lane expansion plan. This implies lower emissions as well,” said Liu.
Let the data speak
Bike lanes often spark heated debates. Some argue they slow down traffic. Others insist they’re the future of clean, healthy cities. Liu offers a third way: “We should let data speak and follow a scientific approach” to evaluate their effectiveness. “Simply taking out bike lanes from the streets would not solve our congestion problem and could likely make it worse.”
