The Propensity to Cycle Tool (PCT) has revolutionised strategic cycle planning in England and Wales. This evidence-based tool quantifies cycling potential at national, city and street scales, leading to the creation of joined-up networks available to millions of people. The PCT has been used by {$>$}35,000 transport planners, consultants, advocates and members of the public, directly influencing the design and construction of cost-effective cycle networks worth {$>$}GBP500,000,000. The tool informed the majority of UK local authority applications to the GBP250,000,000 government COVID-19 Emergency Active Travel Fund. Planners across Europe, USA, Australia and New Zealand have adopted the approach internationally.