1. A method, comprising: determining, using a processor, segments for a plurality of trajectories, wherein each trajectory comprises radio frequency (RF) data from a communication device; determining, using the processor, RF features for the segments; forming, using the processor, clusters of the segments according to the RF features; and generating, using the processor, routes for a map using the clusters; wherein: the RF data comprises Wi-Fi data; the RF features comprise Wi-Fi features; and each Wi-Fi feature comprises a wireless access point identifier and a trend for the wireless access point identifier located at a particular distance along one of the segments.