Vélotropolis: a bike lane supply-demand visual analytics tool

Phil Tinn

Vélotropolis is a prototype supply-demand visualization tool designed with the aim to quickly highlight the gap in the provision of bike lanes across the city. Using available origin-destination data of shared bike systems, the tool derives the theoretical shortest travel path for each journey and overlays its trajectory on the city map. The aggregated layers of cycling trajectories, in turn, form a visual “demand density” on the road network, which can then be easily compared to the presence of bike lanes based on data typically made available through city governments’ open data platforms. The user can also integrate other information, such as the locations of bike accidents as a way to further inform the prioritization of investment on bike lanes in particular areas of the city.  

Based on traffic data analyst INRIX’s latest study in 2019, average Americans lost 99 hours—an equivalent of $1,377 per driver—to congestion, costing $88 billion in annual time lost across the country. Time loss across major cities, such as in Paris, Rome and Sao Paulo, have reached above 160 hours, and in Bogota and Rio de Janeiro, 190 hours. 

As city mayors around the world look for ways to reduce congestion and dependency on cars, cycling has become an indispensable part of their plans, due to its low emissions, space efficiency, and health benefits. The arrival of shared bike systems has made bikes ever-more accessible to existing and new cyclists, contributing to rapid growth in the usage of roads that were designed predominately for cars and the safety of drivers. To ensure the safety and positive riding experience of cyclists, cities need to move quickly to expand their cycling road networks. But given the constraints of time and public funding, how might city governments better prioritize their efforts?