The model was tested in Rio de Janeiro during the period when the Transoeste expressway was being created. The data shows a change in travel patterns among residents, who started to use the new route, from Barra da Tijuca to Madureira. (Before Transoeste was built, they probably used other routes, such as via the city’s south zone.) Accordingly, a way of tracking movements across cities based on cell phone data was developed. This kind of monitoring demonstrated its potential to improve analyses of mobility in Brazil. The matrix based on cell phone data usage permits analysis of two things: events and mobility. In the first case, it is possible to estimate the number of people at a location (at an event) and their origins. The second type of analysis is directly geared at transport engineering decisions. Cell phone data enables faster and more precise analysis of urban mobility, compared with traditional methods, such as interviews, which are expensive, time consuming, slow and hard to predict. From the study, we can conclude that the methodologies developed are innovative and they have the advantage of being easily replicated in various cities. They have the potential to become an important input for planning events and decisions related to traffic engineering.