1. A method comprising: identifying, using a processor, a potential roundabout location from a plurality of probe data points received from a plurality of mobile devices, wherein each of the plurality of probe data points is represented by a location, a heading vector and a velocity; selecting, using the processor, a subset of the plurality of probe data points for the potential roundabout location; normalizing, using the processor, a vector length of the selected subset of the plurality of probe data points; performing, using the processor, a vector fit for the subset of the plurality of probe data points; detecting a roundabout location from the vector fit, and updating a geographic database based on the roundabout location.