1. A computer-implemented method for generating textual directions based on positional data, the method comprising the following steps, performed by one or more processors: receiving positional information comprising a plurality of positional data elements, the plurality of positional data elements specifying corresponding longitudes and latitudes at corresponding ones of a plurality of times; processing the received information to generate a routing graph, the routing graph comprising a plurality of nodes and one or more route links that connect the nodes, the one or more route links being associated with corresponding link information, wherein the processing comprises: identifying, from the received information, a first data element and a second data element, the time specified by the first data element being subsequent to the time specified by the second data element; selecting a first road corresponding to the longitude and latitude specified by the first data element, and a second road corresponding to the longitude and latitude specified by the second data element; determining whether the first and second roads correspond to a common route link, based on at least a portion of the link information; and constructing a portion of the routing graph that includes the common route link, when the first and second roads correspond to the common route link; and generating, based on the corresponding link information, textual directions for traversing a path representative of the routing graph.