Transport routing algorithms have a silent yet vast impact on transport behaviour. Now, with a few taps on a smartphone or clicks on a computer one can find the fastest path between A and B. With the ‘real time’ routing options of services like Google Maps, Graphhopper and the Open Source CycleStreets.net, it’s even possible to receive instructions during the journey. As I discovered during a cycle ride from Lulow to Hereford, this voice guidance can be hugely useful if one has neither a paper map nor the time to carefully plan an optimal route before the trip. Now people are talking about using crowd-sourced data to inform the suggested route, as demonstrated in this paper. See below for insight into developments that will help transport planners and geographers select the best routes in case of disruption to the network.