Access is obtained to call data records (or other data) for a plurality of mobile telephony users. The call data records (or other data) include location-time sequences. For each of the mobile telephony users, corresponding ones of the location-time sequences are segmented into trips; a home-work-school classification model is used to determine a home location and a work-school location, based on the trips; and a trip purpose classification model is used to assign each of the trips a purpose label, based at least on comparing at least one of a start location and an end location for each one of the trips to at least one of the home location and the work-school location determined using the home-work-school classification model. The trips are aggregated into purpose based origin-destination categories based at least on the purpose labels, time ranges of the location-time sequences, and the start and end locations.